ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Member of the Applications Low voltage, high density systems with Intermediate Bus Architectures (IBA) Point-of-load regulators for high performance DSP, FPGA, ASIC, and microprocessors Desktops, servers, and portable computing Broadband, networking, optical, and communications systems Benefits Integrates digital power conversion with intelligent power management Eliminates the need for external power management components Completely programmable via industry-standard I2C communication bus One part that covers all applications Reduces board space, system cost and complexity, and time to market Family Features RoHS lead free and lead-solder-exempt products are available Wide input voltage range: 8V-14V High continuous output current: 40A Programmable output voltage range: 0.5V-3.65V Efficiency up to 94% Active digital current share Single-wire serial communication bus for frequency synchronization, programming, and monitoring Real time voltage, current, and temperature measurements, monitoring, and reporting Optimal voltage positioning with programmable slope of the VI line Overcurrent, overvoltage, undervoltage, and overtemperature protections with programmable thresholds and types Programmable fixed switching frequency 0.5-1.0MHz Programmable turn-on and turn-off delays Programmable turn-on and turn-off voltage slew rates with tracking protection Programmable feedback loop compensation Power Good signal with programmable limits Programmable fault management Start up into the load pre-biased up to 100% Current sink capability Industry standard size through-hole single-in-line package: 1.8"x0.55" Low height of 1.1" Wide operating temperature range: 0 to 70C UL60950, CSA C22.2 No. 60950-00, and TUV EN60950-1:2001 Description Power-One's point-of-load converters are recommended for use with regulated bus converters in an Intermediate Bus Architecture (IBA). The ZY8140 is an intelligent, fully programmable multiphase step-down point-of-load DCDC module integrating digital power conversion and intelligent power management. When used with ZM7000 Series Digital Power Managers, the ZY8140 completely eliminates the need for external components for sequencing, tracking, protection, monitoring, and reporting. All parameters of the ZY8140 are programmable via the industry-standard I2C communication bus and can be changed by a user at any time during product development and service. Reference Documents: ZM7300 Digital Power Manager. Data Sheet ZM7300 Digital Power Manager. Programming Manual Z-One(R) Graphical User Interface ZM00056-KIT USB to I2C Adapter Kit. User Manual ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 1 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 1. Ordering Information ZY 81 40 Product family: ZOne Module Series: Intelligent POL Converter Output Current: 40A y RoHS compliance: No suffix - RoHS compliant with Pb solder exemption1 G - RoHS compliant for all six substances - zz Packaging Option2: R1 - 30 pcs Tray Q1 - 1 pc sample for evaluation only Dash ______________________________________ 1 The solder exemption refers to all the restricted materials except lead in solder. These materials are Cadmium (Cd), Hexavalent chromium (Cr6+), Mercury (Hg), Polybrominated biphenyls (PBB), Polybrominated diphenylethers (PBDE), and Lead (Pb) used anywhere except in solder. 2 Packaging option is used only for ordering and not included in the part number printed on the POL converter label. 3 Z-One evaluation board is available in only one configuration: ZM7300-KIT-HKS. Example: ZY8140G-R1: A 30-piece tray of RoHS compliant POL converters. Each POL converter is labeled ZY8140G. 2. Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings may cause performance degradation, adversely affect longterm reliability, and cause permanent damage to the converter. 3. Parameter Conditions/Description Min Max Units Operating Temperature Controller case temperature 0 105 C Input Voltage 250ms Transient 15 VDC Environmental and Mechanical Specifications Parameter Conditions/Description Min Nom Max Units Ambient Temperature Range 0 70 C Storage Temperature (Ts) -55 125 C 15 grams 500 Hz G oct/min sweeps G ms Weight Frequency Range Magnitude Sweep Rate Repetitions in each axis (Min-Max-Min Sweep) Acceleration Duration Number of shocks in each axis 5 0.5 1 2 50 11 10 MTBF Calculated Per Telcordia Technologies SR-332 23 Peak Reflow Temperature ZY8140 Peak Reflow Temperature ZY8140G Lead Plating ZY8140 and ZY8140G 100% Matte Tin Moisture Sensitivity Level per JEDEC J-STD-020C ZY8140 ZY8140G 2 3 Operating Vibration (sinusoidal) Non-Operating Shock (half sine) ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com MHrs 245 220 C 260 C Page 2 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 4. Electrical Specifications Specifications apply at the input voltage from 8V to 14V, output load from 0 to 40A, ambient temperature from 0C to 70C, 110F ceramic output capacitance, and default performance parameters settings unless otherwise noted. 4.1 4.2 Input Specifications Parameter Conditions/Description Min Input voltage (VIN) Refer to Figure 1 8 Input Current (at no load) VIN=12V Maximum Input Current VIN=8V, VOUT=3.6V Nom Max Units 14 VDC 23 mADC 19.7 ADC Max Units 3.65 VDC VDC Output Specifications Parameter Output Voltage Range (VOUT) Output Voltage Setpoint Accuracy Conditions/Description Min Programmable1 Default (no programming) VIN=12V, IOUT=0.5*IOUT MAX, FSW=500kHz, room temperature 0.5 Nom 0.5 1.2% or 10mV whichever is greater -402 40 %VO.SET Output Current (IOUT) VIN MIN to VIN MAX ADC Line Regulation VIN MIN to VIN MAX 0.5 %VOUT Load Regulation 0 to IOUT MAX 0.5 %VOUT Dynamic Regulation Peak Deviation Settling Time Output Voltage Peak-to-Peak Ripple and Noise BW=20MHz Full Load 50% - 75% load step, Slew rate 1A/s COUT=330F, FSW=1MHz to 10% of peak deviation VIN=12V, VOUT=0.75V VIN=12V, VOUT=1.0V VIN=12V, VOUT=2.5V VIN=12V, VOUT=3.3V 200 25 15 20 25 30 mV s mV mV mV mV Efficiency FSW=500kHz Full Load Room temperature VIN=12V, VOUT=0.5V VIN=12V, VOUT=0.75V VIN=12V, VOUT=1.0V VIN=12V, VOUT=1.2V VIN=12V, VOUT=1.8V VIN=12V, VOUT=2.5V VIN=12V, VOUT=3.3V 75.3 81.9 85.3 87 90.2 92.1 93.5 % % % % % % % Temperature Coefficient VIN=12V, VOUT =2.5V, IOUT=0.5*IOUT MAX 35 ppm/C Switching Frequency (3 phases combined) Default Programmable, 250kHz steps Default Programmable, 0.5% steps 500 Duty Cycle 500 1,000 50 0 50 1 kHz kHz % % ZY8140 is a step-down converter, thus the output voltage is always lower than the input voltage as show in Figure 1. At the negative output current (bus terminator mode) efficiency of the ZY8140 degrades resulting in increased internal power dissipation. Therefore maximum allowable negative current under specific conditions is 20% lower than the current determined from the derating curves shown in paragraph 5.5. 2 ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 3 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Figure 1. Output Voltage as a Function of Input Voltage 4.3 Protection Specifications Parameter Conditions/Description Min Nom Max Units Output Overcurrent Protection Type Threshold Default Programmable Default Programmable in 11 steps Threshold Accuracy 40 Non-Latching, 130ms period Latching/Non-Latching 140 %IOUT 140 %IOUT -25 25 %IOCP.SET Output Overvoltage Protection Default Programmable Default Programmable in 10% steps 1101 Threshold Accuracy Measured at VO.SET=2.5V -2 Delay From instant when threshold is exceeded until the turn-off command is generated Type Threshold ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Non-Latching, 130ms period Latching/Non-Latching 130 %VO.SET 130 %VO.SET 2 %VOVP.SET 6 s Page 4 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Output Undervoltage Protection Default Programmable Default Programmable in 5% steps 75 Non-Latching, 130ms period Latching/Non-Latching 75 %VO.SET 90 %VO.SET Threshold Accuracy Measured at VO.SET=2.5V -2 2 Delay From instant when threshold is exceeded until the turn-off command is generated Type Threshold %VUVP.SET 6 s Overtemperature Protection Type Default Programmable Turn Off Threshold Temperature is increasing 120 C Turn On Threshold Temperature is decreasing after the module was shut down by OTP 110 C Threshold Accuracy Delay Non-Latching, 130ms period Latching/Non-Latching -5 From instant when the controller junction temperature reaches the OTP threshold until the turn-off command is generated 5 2 C ms Tracking Protection (when Enabled) Type Default Programmable Threshold Enabled during output voltage ramping up Threshold Accuracy Delay Disabled Latching/Non-Latching, 130ms period -50 From instant when threshold is exceeded until the turn-off command is generated 250 mVDC 50 mVDC 6 s 120 C Overtemperature Warning Threshold Always enabled, reported in Status register Threshold Accuracy -5 Hysteresis Delay From instant when threshold is exceeded until the warning signal is generated 5 C 3 C 6 s Power Good Signal (PGOOD pin) Logic Lower Threshold VOUT is inside the PG window VOUT is outside the PG window Default Programmable in 5% steps High Low 90 90 Upper Threshold Delay From instant when threshold is exceeded until status of PG signal changes Threshold Accuracy Measured at VO.SET=2.5V -2 N/A 95 110 %VO.SET 6 s 2 ___________________ 1 Minimum OVP threshold is 1.0V ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com %VO.SET %VO.SET Page 5 of 30 %VO.SET ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 4.4 Feature Specifications Parameter Conditions/Description Min Nom Max Units Current Share Type Current Share Accuracy Active, Single Line IOUT MIN20%*IOUT NOM 20 %IOUT 348.75 Degree degree Interleave Interleave (Phase Shift) Default Programmable in 11.25 steps 0 0 Sequencing Turn ON Delay Turn OFF Delay Default Programmable in 1ms steps Default Programmable in 1ms steps 0 0 255 0 0 63 ms ms ms ms Tracking Turn ON Slew Rate Turn OFF Slew Rate Default Programmable in 7 steps Default Programmable in 7 steps 0.1 -8.331 V/ms V/ms V/ms V/ms 0 3.02 mV/A mV/A Programmable 0.05 50 kHz Programmable 0.05 50 kHz Programmable 0.05 50 kHz Programmable 1 1000 kHz Programmable 1 1000 kHz 0.1 -0.1 -0.1 8.331 Optimal Voltage Positioning Load Regulation Default Programmable in 7 steps 0 Feedback Loop Compensation Zero1 (Effects phase lead and increases gain in mid-band) Zero 2 (Effects phase lead and increases gain in mid-band) Pole 1 (Integrator Pole, effects loop gain) Pole 2 (Effects phase lag and limits gain in mid-band) Pole 3 (High frequency low- pass filter to limit PWM noise) Monitoring Voltage Monitoring Accuracy 1 LSB=22mV -1%VOUT - 1 LSB 1%VOUT + 1 LSB mV Current Monitoring Accuracy 30%IOUT NOM <IOUTIOUT NOM 20 20 %IOUT Temperature Monitoring Accuracy Junction temperature of POL controller -5 +5 C 2 Remote Voltage Sense (+VS and -VS pins) Voltage Drop Compensation Between +VS and VOUT 300 mV Voltage Drop Compensation Between -VS and PGND 100 mV ___________________ 1 2 Achieving fast slew rates under specific line and load conditions may require feedback loop adjustment If the voltage sense outputs are connected remotely, it is recommended to place a 0.01-0.1F ceramic capacitor between +VS and -VS pins as close to the POL converter as possible. The capacitor improves noise immunity of the POL converter. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 6 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 4.5 Signal Specifications Parameter Conditions/Description Min Nom Max Units VDD Internal supply voltage 3.15 3.3 3.45 V 0.3 x VDD V VDD + 0.5 V 0.45 x VDD V 60 mA 300 ns 10 pF mA SYNC/DATA Line (SD pin) ViL_sd LOW level input voltage -0.5 ViH_sd HIGH level input voltage Vhyst_sd Hysteresis of input Schmitt trigger VoL LOW level sink current @ 0.5V Tr_sd Maximum allowed rise time 10/90%VDD Cnode_sd Added node capacitance Ipu_sd Pull-up current source at Vsd=0V 0.3 1.0 Freq_sd Clock frequency of external SD line 475 525 0.75 x VDD 0.25 x VDD 14 5 Tsynq Sync pulse duration 22 28 T0 Data=0 pulse duration 72 78 kHz % of clock cycle % of clock cycle ADDR0...ADDR4 Inputs ViL_x LOW level input voltage -0.5 0.3 x VDD V ViH_x HIGH level input voltage 0.7 x VDD VDD+0.5 V Vhyst_x Hysteresis of input Schmitt trigger 0.1 x VDD 0.3 x VDD V RdnL_ADDR External pull down resistance ADDRX forced low 10 kOhm Power Good and OK Inputs/Outputs Iup_PG Pull-up current source input forced low PG 25 110 A Iup_OK Pull-up current source input forced low OK 175 725 A ViL_x LOW level input voltage -0.5 0.3 x VDD V ViH_x HIGH level input voltage 0.7 x VDD VDD+0.5 V Vhyst_x Hysteresis of input Schmitt trigger 0.1 x VDD 0.3 x VDD V IoL LOW level sink current at 0.5V 4 20 mA Current Share Bus (CS pin) Iup_CS Pull-up current source at VCS = 0V 0.84 3.1 mA ViL_CS LOW level input voltage -0.5 0.3 x VDD V ViH_CS HIGH level input voltage VDD+0.5 V Vhyst_CS Hysteresis of input Schmitt trigger 0.45 x VDD V IoL LOW level sink current at 0.5V 60 mA Tr_CS Maximum allowed rise time 10/90% VDD 100 ns ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com 0.75 x VDD 0.25 x VDD 14 Page 7 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 5. Typical Performance Characteristics 5.1 95 Efficiency Curves 90 Efficiency, % Efficiency, % 95 90 85 80 85 Vo=0.75V Vo=1.0V Vo=1.2V Vo=1.8V Vo=2.5V Vo=3.3V Vin=9.6V 75 0.5 1 80 0 10 20 Vin=12V 30 1.5 2 2.5 Output Voltage, V 3 40 Output Current, A Figure 4. Efficiency vs. Output Voltage, Iout=40A, Fsw=500kHz Figure 2. Efficiency vs. Load. Vin=9.6V, Fsw=500kHz 95 Efficiency, % 95 Efficiency, % 90 85 90 80 Vo=0.75V Vo=1.0V Vo=1.2V Vo=1.8V Vo=2.5V Vo=3.3V 10 20 30 Vo=1.8V Vo=2.5V Vo=3.3V 85 8 75 0 Vo=1.0V 40 Output Current, A 9 10 11 12 Input Voltage, V 13 Figure 5. Efficiency vs. Input Voltage. Iout=40A, Fsw=500kHz Figure 3. Efficiency vs. Load. Vin=12V, Fsw=500kHz ZD-01977 Rev. 1.1, 01-Jul-10 14 www.power-one.com Page 8 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 94 92 Efficiency, % 90 88 86 Vo=1.0V Vo=1.8V Vo=2.5V Vo=3.3V 84 82 80 500 750 1000 Switching Frequency, kHz Figure 6. Efficiency vs. Switching Frequency. Vin=12V, Iout=40A 5.2 Figure 8. Turn-On with Different Rising Slew Rates. Rising Slew Rates are Programmed as follows: V1and V2-0.5V/ms, V3-0.2V/ms. Vin=12V, Ch1 - V1, Ch2 - V2, Ch3 - V3 Turn-On Characteristics Figure 7. Tracking Turn-On. Rising Slew Rate is Programmed at 0.5V/ms. Vin=12V, Ch1 - V1, Ch2 - V2, Ch3 - V3 ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Figure 9. Turn On with Sequencing and Tracking. Rising Slew Rate Programmed at 0.5V/ms, V1 and V2 delays are programmed at 5ms. Vin=12V, Ch1 - V1, Ch2 - V2, Ch3 - V3 Page 9 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Figure 10. Turn On into Prebiased Load. V1 and V2 are Prebiased by V3 via a Diode. Vin=12V, Ch1 - V1, Ch2 - V2, Ch3 - V3 Figure 12. Turn-Off with Tracking and Sequencing. Falling Slew Rate is Programmed at 0.5V/ms. Vin=12V, Ch1 - V1, Ch2 - V2, Ch3 - V3 5.3 5.4 Turn-Off Characteristics Transient Response The picture below shows the deviation of the output voltage in response to the 50-75-50% step load at 1A/s. In all tests the ZY8140 converters had the switching frequency of 1MHz and a total of 330F ceramic and tantalum capacitors connected across the output pins. Bandwidth of the feedback loop was programmed for faster transient response. Figure 11. Tracking Turn-Off. Falling Slew Rate is Programmed at 0.5V/ms. Vin=12V, Ch1 - V1, Ch2 - V2, Ch3 - V3 Figure 13. Vin=12V, Vout=2.5V ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 10 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 5.5 Thermal Derating Curves 40 Load Current, A 35 30 25 0 LFM 100 LFM (0.5 m/s) 200 LFM (1 m/s) 300 LFM (1.5 m/s) 400 LFM (2 m/s) 500 LFM (2.5 m/s) 20 15 25 35 45 55 65 75 Ambient Temperature, C Figure 14. Thermal Derating Curves. Vin=12V, Vout=3.3V, Fsw=500kHz 40 Load Current, A 35 30 25 0 LFM 100 LFM (0.5 m/s) 200 LFM (1 m/s) 300 LFM (1.5 m/s) 400 LFM (2 m/s) 500 LFM (2.5 m/s) 20 15 25 35 45 55 65 75 Ambient Temperature, C Figure 15. Thermal Derating Curves. Vin=12V, Vout=3.3V, Fsw=1MHz ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 11 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 6. Typical Application 2 Figure 16. Block Diagram of Typical Multiple Output Application with Digital Power Manager and I C Interface The schematic of a typical application of ZY8140 point-of-load converters (POL) is shown in Figure 16. The system includes a ZM7300 series Digital Power Manager (DPM), a ZY8140 POL, and may include additional ZY8140 POLs and other Z-One(R) series POLs. All POLs are connected to the DPM and to each other via a singlewire SD (sync/data) line. The line provides synchronization of all POLs to the master clock generated by the DPM and simultaneously performs data transfer between POLs and the DPM. Each POL has a unique 5-bit address programmed by grounding respective address pins. To enable the current share, CS pins of POLs connected in parallel are interconnected. In addition to the SD line, OK pins of the POLs are connected to the respective OK pins of the DPM. A number of POLs connected to the same OK pin of the DPM forms a group. Grouping of POLs enables users to program, control, and monitor multiple POLs simultaneously and execute advanced fault management schemes. The type, value, and the number of output capacitors shown in the schematic are required to meet the specifications published in the data sheet. However, ZY8140 POLs are fully operational with different parameters of output capacitors. The feedback loop compensation may need to be adjusted to optimize performance of the POLs for specific parameters of the output capacitors. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 12 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 7. Pin Assignments and Description Pin Name Pin Number Pin Type Buffer Type Pin Description Notes OK 6 I/O PU Fault/Status Condition Connect to OK pin of other Z-POL and/or DPM. Leave floating, if not used SD 4 I/O PU Sync/Data Line Connect to SD pin of DPM PGOOD 11 I/O PU Power Good CS 3 I/O PU Current Share Connect to CS pin of other Z-POLs connected in parallel ADDR4 5 I PU POL Address Bit 4 Tie to GND for 0 or leave floating for 1 ADDR3 10 I PU POL Address Bit 3 Tie to GND for 0 or leave floating for 1 ADDR2 9 I PU POL Address Bit 2 Tie to GND for 0 or leave floating for 1 ADDR1 8 I PU POL Address Bit 1 Tie to GND for 0 or leave floating for 1 ADDR0 7 I PU POL Address Bit 0 Tie to GND for 0 or leave floating for 1 -VS 18 I A Negative Voltage Sense Connect to the negative point close to the load +VS 15 I A Positive Voltage Sense Connect to the positive point close to the load VOUT 12, 13 P Output Voltage GND 2, 16, 17 P Power Ground VIN 1 P Input Voltage Legend: I=input, O=output, I/O=input/output, P=power, A=analog, PU=internal pull-up ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 13 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 8. Programmable Features Performance parameters of ZY8140 POL converters can be programmed via the industry standard I2C communication bus without replacing any components or rewiring PCB traces. Each parameter has a default value stored in the volatile memory registers detailed in Table 1. The setup registers 00h through 14h are programmed at the system power-up. When the user programs new performance parameters, the values in the registers are overwritten. Upon removal of the input voltage, the default values are restored. Table 1. ZY8140 Memory Registers Register PC1 PC2 PC3 DON DOF TC INT RUN ST VOS CLS DCL B1 B2 B3 C0L C0H C1L C1H C2L C2H C3L C3H VOM IOM TMP Content Protection Configuration 1 Protection Configuration 2 Protection Configuration 3 Turn-On Delay Turn-Off Delay Tracking Configuration Interleave Configuration and Frequency Selection RUN Register Status Register Output Voltage Setpoint Current Limit Setpoint Duty Cycle Limit Dig Controller Denominator z-1 Coefficient Dig Controller Denominator z-2 Coefficient Dig Controller Denominator z-3 Coefficient Dig Controller Numerator z0 Coefficient, Low Byte Dig Controller Numerator z0 Coefficient, High Byte Dig Controller Numerator z-1 Coefficient, Low Byte Dig Controller Numerator z-1 Coefficient, High Byte Dig Controller Numerator z-2 Coefficient, Low Byte Dig Controller Numerator z-2 Coefficient, High Byte Dig Controller Numerator z-3 Coefficient, High Byte Dig Controller Numerator z-3 Coefficient, Low Byte Output Voltage Monitoring Output Current Monitoring Temperature Monitoring Address 00h 01h 02h 05h 06h 03h 04h ZY8140 converters can be programmed using the Graphical User Interface or directly via the I2C bus by using high and low level commands as described in the `"DPM Programming Manual". ZY8140 parameters can be reprogrammed at any time during the system operation and service except for the digital filter coefficients, the switching frequency and the duty cycle limit, that can only be changed when the POL output is turned off. 8.1 Output Voltage The output voltage can be programmed in the GUI Output Configuration window shown in the Figure 17 or directly via the I2C bus by writing into the VOS register shown in Figure 18. 15h 16h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh Figure 17. Output Configuration Window 0Fh 10h 11h 12h 13h 14h 17h 18h 19h R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 VOS7 VOS6 VOS5 VOS4 VOS3 VOS2 VOS1 VOS0 Bit 7 Bit 0 Bit 7:0 VOS[7:0], Output voltage setting 00h: corresponds to 0.5000V 01h: corresponds to 0.5125V ... 77h: corresponds to 1.9875V 78h: corresponds to 2.0000V 79h: corresponds to 2.025V ... R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset ... BAh: corresponds to 3.650V Figure 18. Output Voltage Setpoint Register VOS ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 14 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 8.1.1 Output Voltage Setpoint The output voltage programming range is from 0.5V to 3.65V. To improve the resolution of the output voltage settings, the voltage range is divided into sub-ranges as shown in Table 2. Table 2. Output Voltage Adjustment Resolution VOUT MIN, V VOUT MAX, V Resolution, mV 0.500 2.000 12.5 2.025 2.75 25 VOUT Upper Regulation Limit Lower Regulation Limit Operating Point VI Curve Without Load Regulation VI Curve With Load Regulation Headroom without Load Regulation Headroom with Load Regulation Light Load IOUT Heavy Load Figure 19. Concept of Optimal Voltage Positioning 8.1.2 Output Voltage Margining If the output voltage needs to be varied by a certain percentage, the margining function can be utilized. The margining can be programmed in the GUI Output Configuration window or directly via the I2C bus using high level commands as described in the `"DPM Programming Manual". In order to properly margin POLs that are connected in parallel, the POLs must be members of one of the Parallel Buses. Refer to the GUI System Configuration Window shown in Figure 45. 8.1.3 Optimal Voltage Positioning Optimal voltage positioning increases the voltage regulation window by properly positioning the output voltage setpoint. Positioning is determined by the load regulation that can be programmed in the GUI Output Configuration window shown in Figure 17 or directly via the I2C bus by writing into the CLS register shown in Figure 28. Figure 19 illustrates optimal voltage positioning concept. If no load regulation is programmed, the headroom (voltage differential between the output voltage setpoint and a regulation limit) is approximately half of the voltage regulation window. When load regulation is programmed, the output voltage will decrease as the output current increases, so the VI characteristic will have a negative slope. Therefore, by properly selecting the operating point, it is possible to increase the headroom as shown in the picture. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Increased headroom allows tolerating larger voltage deviations. For example, the step load change from light to heavy load will cause the output voltage to drop. If the optimal voltage positioning is utilized, the output voltage will stay within the regulation window. Otherwise, the output voltage will drop below the lower regulation limit. To compensate for the voltage drop external output capacitance will need to be added, thus increasing cost and complexity of the system. The effect of optimal voltage positioning is shown in Figure 20 and Figure 21. In this case, switching output load causes large peak-to-peak deviation of the output voltage. By programming load regulation, the peak to peak deviation is dramatically reduced. Figure 20. Transient Response without Optimal Voltage Positioning Page 15 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 DON7 DON6 DON5 DON4 DON3 DON2 DON1 DON0 Bit 7 Bit 0 Bit 7:0 DON[7:0]: Turn-on delay time 00h: corresponds to 0ms delay after turn-on command has occurred ... FFh: corresponds to 255ms delay after turn-on command has occurred Figure 23. Turn-On Delay Register DON 8.2.2 Turn-Off Delay U U R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 --- --- DOF5 DOF4 DOF3 DOF2 DOF1 DOF0 Bit 7 Bit 0 Bit 7:6 Unimplemented, read as `0' Figure 21. Transient Response with Optimal Voltage Positioning 8.2 Bit 5:0 DOF[5:0]: Turn-off delay time 00h: corresponds to 0ms delay after turn-off command has occurred ... 3Fh: corresponds to 63ms delay after turn-off command has occurred Figure 24. Turn-Off Delay Register DOF Sequencing and Tracking Turn-on delay, turn-off delay, and rising and falling output voltage slew rates can be programmed in the GUI Sequencing/Tracking window shown in Figure 22 or directly via the I2C bus by writing into the DON, DOF, and TC registers, respectively. The registers are shown in Figure 23, Figure 24, and Figure 26. Turn-off delay is defined as an interval from the application of the Turn-Off command until the output voltage reaches zero (if the falling slew rate is programmed) or until both high side and low side switches are turned off (if the slew rate is not programmed). Therefore, for the slew rate controlled turn-off the ramp-down time is included in the turn-off delay as shown in Figure 25. User programmed turn-off delay, TDF Turn-Off Command Internal ramp-down command VOUT Calculated delay TD Ramp-down time, TF Falling slew rate dVF/dT Figure 22. Sequencing/Tracking Window 8.2.1 Turn-On Delay Turn-on delay is defined as an interval from the application of the Turn-On command until the output voltage starts ramping up. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Time Figure 25. Relationship between Turn-Off Delay and Falling Slew Rate As it can be seen from the figure, the internally calculated delay TD is determined by the equation below. V TD TDF OUT , dVF dT For proper operation TD shall be greater than zero. The appropriate value of the turn-off delay needs to be programmed to satisfy the condition. Page 16 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet If the falling slew rate control is not utilized, the turnoff delay only determines an interval from the application of the Turn-Off command until both high side and low side switches are turned off. In this case, the output voltage ramp-down process is determined by load parameters. 8.2.3 Rising and Falling Slew Rates The output voltage tracking is accomplished by programming the rising and falling slew rates of the output voltage. To achieve programmed slew rates, the output voltage is being changed in 12.5mV steps where duration of each step determines the slew rate. For example, ramping up a 1.0V output with a slew rate of 0.5V/ms will require 80 steps duration of 25s each. Duration of each voltage step is calculated by dividing the master clock frequency generated by the DPM. Since all POLs in the system are synchronized to the master clock, the matching of voltage slew rates of different outputs is very accurate as it can be seen in Figure 7 and Figure 11. During the turn on process, a POL not only delivers current required by the load (ILOAD), but also charges the load capacitance. The charging current can be determined from the equation below: ICHG CLOAD dVR U R/W-0 R/W-0 R/W-0 R/W-1 R/W-0 R/W-0 --- R2 R1 R0 SC F2 F1 Bit 7 Bit 7 F0 Bit 0 Unimplemented , read as `0' R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset Bit 6:4 R[2:0]: Value of Vo rising slope 0: corresponds to 0.1V/ms (default) 1: corresponds to 0.2V/ms 2: corresponds to 0.5V/ms 3: corresponds to 1.0V/ms 4: corresponds to 2.0V/ms 5: corresponds to 5.0V/ms 6: corresponds to 8.3V/ms 7: corresponds to 8.3V/ms Bit 3 R/W-0 SC, Slew rate control at turn-off 0: Slew rate control is disabled 1: Slew rate control is enabled Bit 2:0 F[2:0]: Value of Vo falling slope 0: corresponds to -0.1V/ms (default) 1: corresponds to -0.2V/ms 2: corresponds to -0.5V/ms 3: corresponds to -1.0V/ms 4: corresponds to -2.0V/ms 5: corresponds to -5.0V/ms 6: corresponds to -8.3V/ms 7: corresponds to -8.3V/ms Figure 26. Tracking Configuration Register TC 8.3 Protections ZY8140 Series converters have a comprehensive set of programmable protections. The set includes the output over- and undervoltage protections, overcurrent protection, overtemperature protection, tracking protection, overtemperature warning, and Power Good signal. Status of protections is stored in the ST register shown in Figure 27. dt Where, CLOAD is load capacitance, dVR/dt is rising voltage slew rate, and ICHG is charging current. When selecting the rising slew rate, a user needs to ensure that I LOAD ICHG IOCP Where IOCP is the overcurrent protection threshold of the ZY8140. If the condition is not met, then the overcurrent protection will be triggered during the turn-on process. To avoid this, dVR/dt and the overcurrent protection threshold should be programmed to meet the condition above. R-1 R-0 R-1 R-1 R-1 R-1 R-1 TP PG TR OT OC UV OV Bit 7 R-1 PV Bit 0 Bit 7 TP: Temperature Warning Bit 6 PG: Power Good Warning Bit 5 TR: Tracking Fault Bit 4 OT: Overtemperature Fault Bit 3 OC: Overcurrent Fault Bit 2 UV: Undervoltage Fault Bit 1 OV: Overvoltage Error Bit 0 PV: Phase Voltage Error (Not Active) R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset Note: - An activated warning/fault/error is encoded as `0' Figure 27. Protection Status Register ST Thresholds of overcurrent, over- and undervoltage protections, and Power Good limits can be programmed in the GUI Output Configuration window or directly via the I2C bus by writing into the CLS and PC2 registers shown in Figure 28 and Figure 29. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 17 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-0 R/W-1 R/W-1 LR2 LR1 LR0 TCE CLS3 CLS2 CLS1 CLS0 Bit 7 Bit 0 Bit 7:5 LR[2:0], Load regulation configuration 000: 0 V/A/Ohm 001: 0.39 V/A/Ohm 010: 0.78 V/A/Ohm 011: 1.18 V/A/Ohm 100: 1.57 V/A/Ohm 101: 1.96 V/A/Ohm 110: 2.35 V/A/Ohm 111: 2.75 V/A/Ohm Bit 4 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset TCE, Temperature compensation enable 0: disabled 1: enabled Bit 3:0 CLS[3:0], Current limit setting 0h: corresponds to 37% 1h: corresponds to 47% ... Bh: corresponds to 140% Values higher than Bh are translated to Bh (140%) Figure 30. Fault Management Window Figure 28. Current Limit Setpoint Register CLS U U U R/W-0 R/W-1 R/W-0 R/W-0 R/W-0 --- --- --- PGLL OVPL1 OVPL0 UVPL1 UVPL0 R/W-0 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-1 TRE PVE TRP OTP OCP UVP OVP Bit 7 TRE: Tracking fault enable 1 = enabled 0 = disabled Bit 6 PVE: Phase voltage error enable 1 = enabled 0 = disabled Bit 5 TRP: Tracking fault protection 1 = latching 0 = non latching Bit 4 OTP: Overtemperature protection configuration 1 = latching 0 = non latching Bit 3 OCP: Overcurrent protection configuration 1 = latching 0 = non latching Bit 2 UVP: Undervoltage protection configuration 1 = latching 0 = non latching Figure 29. Protection Configuration Register PC2 Bit 1 OVP: Overvoltage protection configuration 1 = latching 0 = non latching Note that the overvoltage and undervoltage protection thresholds and Power Good limits are defined as percentages of the output voltage. Therefore, the absolute levels of the thresholds change when the output voltage setpoint is changed either by output voltage adjustment or by margining. Bit 0 PVP: Phase Voltage Protection (Not Active) 1 = latching 0 = non latching Bit 7:5 Unimplemented , read as `0' PGLL: Set Power Good Low Level Bit 4 1 = 95% of Vo 0 = 90% of Vo (Default) Bit 3:2 OVPL[1:0] : Set Over Voltage Protection Level 00 = 110% of Vo 01 = 120% of Vo 10 = 130% of Vo (Default) 11 = 130% of Vo Bit 0 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset Bit 1:0 UVPL[1:0] : Set Under Voltage Protection Level 00 = 75% of Vo (Default) 01 = 80% of Vo 10 = 85% of Vo 11 = 90% of Vo In addition, a user can change type of protections (latching or non-latching) or disable certain protections. These settings are programmed in the GUI Fault Management window shown in Figure 30 or directly via the I2C by writing into the PC1 register shown in Figure 31. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com PVP Bit 0 Bit 7 Bit 7 R/W-1 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset Figure 31. Protection Configuration Register PC1 If the non-latching protection is selected, a POL will attempt to restart every 130ms until the condition that triggered the protection is removed. When restarting, the output voltages follow tracking and sequencing settings. If the latching type is selected, a POL will turn off and stay off. The POL can be turned on after 130ms, if the condition that caused the fault is removed and the respective bit in the ST register was cleared, or the Turn On command was recycled, or the input voltage was recycled. Page 18 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet All protections can be classified into three groups based on their effect on system operation: warnings, faults, and errors. 8.3.1 Warnings This group includes Overtemperature Warning and Power Good Signal. The warnings do not turn off POLs but rather generate signals that can be transmitted to a host controller via the I2C bus. 8.3.1.1 Overtemperature Warning The Overtemperature Warning is generated when temperature of the controller exceeds 120C. The Overtemperature Warning changes the PT bit of the status register ST to 0 and sends the signal to the DPM. Reporting is enabled in the GUI Fault Management window or directly via the I2C by writing into the PC3 register shown in Figure 33. When the temperature falls below 117C, the PT bit is cleared and the Overtemperature Warning is removed. 8.3.1.2 Power Good Power Good is an open collector output that is pulled low, if the output voltage is outside of the Power Good window. The window is formed by the Power Good High threshold that is equal to 110% of the output voltage and the Power Good Low threshold that can be programmed at 90 or 95% of the output voltage. The Power Good protection is only enabled after the output voltage reaches its steady state level. The PGOOD pin is pulled low during transitions of the output voltage from one level to other as shown in Figure 32. The Power Good Warning pulls the Power Good pin low and changes the PG bit of the status register ST to 0. It sends the signal to the DPM, if the reporting is enabled. When the output voltage returns within the Power Good window, the PG pin is pulled high, the PG bit is cleared and the Power Good Warning is removed. The Power Good pin can also be pulled low by an external circuit to initiate the Power Good Warning. Note: To retrieve status information, Status Monitoring in the GUI POL Group Configuration Window should be enabled (refer to Digital Power Manager Data Sheet). The DPM will retrieve the status information from each POL on a continuous basis. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com 8.3.2 Faults This group includes overcurrent, overtemperature, undervoltage, and tracking protections. Triggering any protection in this group will turn off the POL. 8.3.2.1 Overcurrent Protection Overcurrent protection is active whenever the output voltage of the POL exceeds the prebias voltage (if any). When the output current reaches the OC threshold, the output voltage will start decreasing. As soon as the output voltage decreases below the undervoltage protection threshold, the OC fault signal is generated, the POL turns off and the OC bit in the register ST is changed to 0. Both high side and low side switches of the POL are turned off instantly (fast turn-off). The temperature compensation is added to keep the OC threshold approximately constant at temperatures above room temperature. Note that the temperature compensation can be disabled in the GUI Output Configuration window or directly via the I2C by writing into the CLS register. However, it is recommended to keep the temperature compensation enabled. 8.3.2.2 Undervoltage Protection The undervoltage protection is only active during steady state operation of the POL to prevent nuisance tripping. If the output voltage decreases below the UV threshold and there is no OC fault, the UV fault signal is generated, the POL turns off, and the UV bit in the register ST is changed to 0. The output voltage is ramped down according to sequencing and tracking settings (regular turn-off). 8.3.2.3 Overtemperature Protection Overtemperature protection is active whenever the POL is powered up. If temperature of the controller exceeds 120C, the OT fault is generated, POL turns off, and the OT bit in the register ST is changed to 0. The output voltage is ramped down according to sequencing and tracking settings (regular turn-off). If non-latching OTP is programmed, the POL will restart as soon as the temperature of the controller decreases below the Overtemperature Warning threshold of 110C. Page 19 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 8.3.2.4 Tracking Protection Tracking protection is active only when the output voltage is ramping up. The purpose of the protection is to ensure that the voltage differential between multiple rails being tracked does not exceed 250mV. This protection eliminates the need for external clamping diodes between different voltage rails which are frequently recommended by ASIC manufacturers. When the tracking protection is enabled, the POL continuously compares actual value of the output voltage to its programmed value as defined by the output voltage and its rising slew rate. If absolute value of the difference exceeds 250mV, the tracking fault signal is generated, the POL turns off, and the TR bit in the register ST is changed to 0. Both high side and low side switches of the POL are turned off instantly (fast turn-off). The tracking protection can be disabled, if it contradicts requirements of a particular system (for example turning into high capacitive load where rising slew rate is not important). It can be disabled in the GUI Fault Management window or directly via the I2C bus by writing into the PC1 register. Vo Enable command 1 0 OTP continuously enabled 1 0 OCP enabled Power Good Signal 1 0 OVP Threshold OVP Threshold PG High=110%VOUT PG High=110%VOUT OVP Threshold Output Voltage 1.0V prebiased output Output Voltage PG High=110%VOUT PG Low Threshold Output Voltage PG Low Threshold UVP Threshold PG Low Threshold UVP Threshold UVP Threshold Tracking Thresholds Time Figure 32. Protections Enable Conditions 8.3.3 Errors The group includes overvoltage protection and the phase voltage error. The phase voltage error is not available in ZY8140. 8.3.3.1 Overvoltage Protection The overvoltage protection is active whenever the output voltage of the POL exceeds the pre-bias voltage (if any). If the output voltage exceeds the overvoltage protection threshold, the overvoltage error signal is generated, the POL turns off, and the OV bit in the register ST is changed to 0. The high side switch is turned off instantly, and simultaneously the low side switch is turned on to ensure reliable protection of sensitive loads. The low side switch provides low impedance path to quickly dissipate ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com energy stored in the output filter and achieve effective voltage limitation. The OV threshold can be programmed from 110% to 130% of the output voltage setpoint, but not lower than 1.0V. 8.3.4 Faults and Errors Propagation The feature adds flexibility to the fault management scheme by giving users control over propagation of fault signals within and outside of the system. The propagation means that a fault in one POL can be programmed to turn off other POLs and devices in the system, even if they are not directly affected by the fault. Page 20 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 8.3.4.1 Grouping of POLs Z-Series POLs can be arranged in several groups to simplify fault management. A group of POLs is defined as a number of POLs with interconnected OK pins. A group can include from 1 to 32 POLs. If fault propagation within a group is desired, the propagation bit needs to be checked in the GUI Fault Management Window. The parameters can also be programmed directly via the I2C bus by writing into the PC3 register shown in Figure 33. When propagation is enabled, the faulty POL pulls its OK pin low. A low OK line initiates turn-off of other POLs in the group. R/W-0 R/W-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 PTM PGM TRP OTP OCP UVP OVP Bit 7 R/W-1 PVP Bit 0 Bit 7 PTM : Temperature warning Message 1 = enabled 0 = disabled Bit 6 PGM: Power good message 1 = enabled 0 = disabled Bit 5 TRP : Tracking fault propagation 1 = enabled 0 = disabled Bit 4 OTP: Overtemperature fault propagation 1 = enabled 0 = disabled Bit 3 OCP: Overcurrent fault propagation 1 = enabled 0 = disabled Bit 2 UVP: Undervoltage fault propagation 1 = enabled 0 = disabled Bit 1 OVP : Overvoltage error propagation 1 = enabled 0 = disabled Bit 0 PVP : Phase voltage error propagation (Not Active) 1 = enabled 0 = disabled R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset Figure 34. Fault and Error Propagation Window In this case low OK line will signal DPM to pull other OK lines low to initiate shutdown of other POLs as programmed in the GUI Fault and Error Propagation window. If an error is propagated, the DPM can also generate commands to turn off a front end (a DC-DC converter generating the intermediate bus voltage) and trigger an optional crowbar protection to accelerate removal of the IBV voltage. 8.3.4.2 Propagation Process Propagation of a fault (OCP, UVP, OTP, and TRP) initiates regular turn-off of other POLs. The faulty POL in this case performs either the regular or the fast turn-off depending on a specific fault as described in section 8.3.2. Propagation of an error initiates fast turn-off of other POLs. The faulty POL performs the fast turn-off and turns on its low side switch. Figure 33. Protection Configuration Register PC3 In addition, the OK lines can be connected to the DPM to facilitate propagation of faults and errors between groups. One DPM can control up to 4 independent groups. To enable fault propagation between groups, the respective bit needs to be checked in the GUI Fault and Error Propagation window shown in Figure 34. Example of the fault propagation is shown in Figure 35 - Figure 36. In this three-output system (refer to the block diagram in Figure 16), the POL powering the output V3 (Ch 1 in the picture) encounters the undervoltage fault after the turn-on. When the fault propagation is not enabled, the POL turns off and generates the UV fault signal. Because the UV fault triggers the regular turn off, the POL meets its turnoff delay and falling slew rate settings during the turn-ff process as shown in Figure 35. Since the UV fault is programmed to be non-latching, the POL will attempt to restart every 130ms, repeating the process described above until the condition causing the undervoltage is removed. If the fault propagation between groups is enabled, the POL powering the output V3 pulls its OK line low and the DPM propagates the signal to the POL powering the output V1 that belongs to other group. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 21 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet The POL powering the output V1 (Ch3 in the picture) executes the regular turn-off. Since both V1 and V3 have the same delay and slew rate settings they will continue to turn off and on synchronously every 130ms as shown in Figure 36 until the condition causing the undervoltage is removed. The POL powering the output V2 continues to ramp up until it reaches its steady state level. 130ms is the interval from the instant of time when the output voltage ramps down to zero until the output voltage starts to ramp up again. Therefore, the 130ms hiccup interval is guaranteed regardless of the turn-off delay setting. Figure 36. Turn-On into UVP on V3. The UV Fault Is Programmed To Be Non-Latching and Propagate From Group C to Group A. Ch1 - V3 (Group C), Ch2 - V2, Ch3 - V1 (Group A) Summary of protections, their parameters and features are shown in Table 3 Figure 35. Turn-On into UVP on V3. The UV Fault Is Programmed To Be Non-Latching. Ch1 - V3 (Group C), Ch2 - V2, Ch3 - V1 (Group A) Table 3. Summary of Protections Parameters and Features Whenever VIN is applied Turn Off No Low Side Switch N/A Warning During steady state No N/A Tracking Fault During ramp up Fast OT Overtemperature Fault Whenever VIN is applied OC Overcurrent Fault UV Undervoltage OV Overvoltage Propagation Disable No Off Sends signal to DPM Sends signal to DPM Regular turn off Yes Regular Off Regular turn off No When VOUT exceeds prebias Fast Off Regular turn off No Fault During steady state Regular Off Regular turn off No Error When VOUT exceeds prebias Fast On Fast turn off No Code Name Type When Active PT Warning PG Temperature Warning Power Good TR ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 22 of 30 No ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 8.4 PWM Parameters Z-Series POLs utilize the digital PWM controller. The controller enables users to program most of the PWM performance parameters, such as switching frequency, interleave, duty cycle, and feedback loop compensation. 8.4.1 Switching Frequency The switching frequency can be programmed in the GUI PWM Controller window shown in Figure 37 or directly via the I2C bus by writing into the INT register shown in Figure 38. Note that the content of the register can be changed only when the POL is turned off. Switching actions of all POLs connected to the SD line are synchronized to the master clock generated by the DPM. Each POL is equipped with a PLL and a frequency divider so they can operate at multiples (including fractional) of the master clock frequency as programmed by a user. The POL converters can operate at 500kHz, 750kHz, and 1MHz. Although synchronized, switching frequencies of different POLs are independent of each other. It is permissible to mix POLs operating at different frequencies in one system. It allows optimizing efficiency and transient response of each POL in the system individually. R/W-0 R/W-0 R/W-0 R/W-0 1) R/W-0 1) R/W-0 1) R/W-0 1) R/W-0 1) FRQ2 FRQ1 FRQ0 INT4 INT3 INT2 INT1 INT0 Bit 7 Bit 0 Bit 7:5 FRQ[2:0] : PWM Frequency Selection 000: 500kHz 001: 750kHz 010: 1000kHz R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset Bit 4:0 INT[4:0] : Interleave position 00h: Ton starts with 0.0 Phase lag to SD Line 01h: Ton starts with 11.25 Phase lag to SD Line 02h: Ton starts with 22.50 Phase lag to SD Line ... 1Fh: Ton starts with 348.75 Phase lag to SD Line 1) Initial value depends on the state of the Interleave Mode ( IM) Input: IM=Open: At POR reset the 5 corresponding ADDRESS bits are loaded IM=Low: At POR reset a 0 is loaded Figure 38. Interleave Configuration Register INT 8.4.2 Interleave Interleave is defined as a phase delay between the synchronizing slope of the master clock on the SD pin and PWM signal of a POL. The interleave can be programmed in the GUI PWM Controller window or directly via the I2C bus by writing into the INT register. Every POL generates switching noise. If no interleave is programmed, all POLs in the system switch simultaneously and noise reflected to the input source from all POLs is added together as shown in Figure 39. Figure 39. Input Voltage Noise, No Interleave Figure 37. PWM Controller Window ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 23 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Figure 40 shows the input voltage noise of the threeoutput system with programmed interleave. Instead of all three POLs switching at the same time as in the previous example, the POLs V1, V2, and V3 switch at 67.5, 180, and 303.75, respectively. Noise is spread evenly across the switching cycle resulting in more than 1.5 times reduction. To achieve similar noise reduction without the interleave will require the addition of an external LC filter. Figure 41. Output Voltage Noise, Full Load, No Interleave Figure 40. Input Voltage Noise with Interleave Similar noise reduction can be achieved on the output of POLs connected in parallel. Figure 41 and Figure 42 show the output noise of two POLs connected in parallel without and with a 180 interleave, respectively. Resulting noise reduction is more than 2 times and is equivalent to doubling switching frequency or adding extra capacitance on the output of the POLs. ZY8140 interleave is independent of the number of POLs in a system and is fully programmable in 11.25 steps. It allows maximum output noise reduction by intelligently spreading switching energy. Note: Due to noise sensitivity issues that may occur in limited cases, it is recommended to avoid phase lag settings of 112.5 and 123.75 degrees, otherwise false PG and/or OV indications may occur. Figure 42. Output Voltage Noise, Full Load, 180 Interleave 8.4.3 Duty Cycle Limit The ZY8140 is a step-down converter therefore VOUT is always less than VIN. The relationship between the two parameters is characterized by the duty cycle and can be estimated from the following equation: V DC OUT , VIN .MIN Where, DC is the duty cycle, VOUT is the required maximum output voltage (including margining), VIN.MIN is the minimum input voltage. It is good practice to limit the maximum duty cycle of the PWM controller to a somewhat higher value compared to the steady-state duty cycle as expressed by the above equation. This will further ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 24 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet protect the output from excessive voltages. The duty cycle limit can be programmed in the GUI PWM Controller window or directly via the I2C bus by writing into the DCL register shown in Figure 43. R/W -1 R/W -1 R/W -1 R/W -0 R/W -1 R/W -0 R/W-0 DCL5 DCL4 DCL3 DCL2 DCL1 DCL0 HI Bit 7 R/W-0 LO Bit 0 Bit 7:2 DCL[5:0], Duty Cycle Limitation 00h: 0 01h: 1/192 ... 60h: 96/192 Bit 1: HI, ADC high saturation feed -forward 0: disabled 1: enabled Bit 0: LO, ADC low saturation feed -forward 0: disabled 1: enabled 8.4.5 Feedback Loop Compensation Feedback loop compensation can be programmed in the GUI PWM Controller window by setting frequency of poles and zeros of the transfer function. R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset The transfer function of the POL converter is shown in Figure 44. It is a third order function with two zeros and three poles. Pole 1 is the integrator pole, Pole 2 is used in conjunction with Zero 1 and Zero 2 to adjust the phase lead and limit the gain increase in mid band. Pole 3 is used as a high frequency lowpass filter to limit PWM noise. Magnitude[dB] Z1 50 P1 Z2 P2 P3 P1: Pole 1 P2: Pole 3 P3: Pole 3 Z1: Zero 1 Z2: Zero 2 40 Figure 43. Duty Cycle Limit Register 30 8.4.4 ADC Saturation Feedforward To speed up the PWM response in case of heavy dynamic loads, the duty cycle can be forced either to 0 or the duty cycle limit depending on the polarity of the transient. This function is equivalent to having two comparators defining a window around the output voltage setpoint. When an error signal is inside the window, it will produce gradual duty cycle change proportional to the error signal. If the error signal goes outside the window (usually due to large output current steps), the duty cycle will change to its limit in one switching cycle. In most cases this will significantly improve transient response of the controller, reducing amount of required external capacitance. Under certain circumstances, usually when the maximum duty cycle limit significantly exceeds its nominal value, the ADC saturation can lead to the overcompensation of the output error. The phenomenon manifests itself as low frequency oscillations on the output of the POL. It can usually be reduced or eliminated by disabling the ADC saturation or limiting the maximum duty cycle to 120140% of the calculated value. It is not recommended to use ADC saturation for output voltages higher than 2.0V. The ADC saturation feedforward can be programmed in the GUI PWM Controller window or directly via the I2C bus by writing into the DCL register. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com 20 10 0.1 1 10 100 1000 0.1 1 10 100 1000 Freq [kHz] Phase [] +45 0 Freq [kHz] -45 -90 -135 -180 Figure 44. Transfer Function of PWM Positions of poles and zeroes are determined by coefficients of the digital filter. The filter is characterized by four numerator coefficients (C0, C1, C2, C3) and three denominator coefficients (B1, B2, B3). The coefficients are automatically calculated when desired frequency of poles and zeros is entered in the GUI PWM Controller window. The coefficients are stored in the C0H, C0L, C1H, C1L, C2H, C2L, C3H, C3L, B1, B2, and B3 registers. Note: The GUI automatically transforms zero and pole frequencies into the digital filter coefficients. It is strongly recommended to use the GUI to determine the filter coefficients. Programming feedback loop compensation allows optimizing POL performance for various application conditions. For example, increase in bandwidth can significantly improve dynamic response. Page 25 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 8.5 Current Share The POL converters are equipped with the digital current share function. To activate the current share, interconnect the CS pins of the POLs connected in parallel. The digital signal transmitted over the CS line sets output currents of all POLs to the same level. When POLs are connected in parallel, they must be included in the same parallel bus in the GUI System Configuration window shown in Figure 45. In this case, the GUI automatically copies parameters of one POL onto all POLs connected to the parallel bus. It makes it impossible to configure different performance parameters for POLs connected in parallel except for interleave and load regulation settings that are independent. The interleave allows to reduce and move the output noise of the converters connected in parallel to higher frequencies as shown in Figure 41 and Figure 42. The load regulation allows controlling the current share loop gain in case of small signal oscillations. It is recommended to always add a small amount of load regulation to one of the converters connected in parallel to reduce loop gain and therefore improve stability. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com 8.6 Performance Parameters Monitoring The POL converters can monitor their own performance parameters such as output voltage, output current, and temperature. The output voltage is measured at the output sense pins, output current is measured using the ESR of the output inductor and temperature is measured by the thermal sensor built into the controller IC. Output current readings are adjusted based on temperature readings to compensate for the change of ESR of the inductor with temperature. An 8-Bit Analog to Digital Converter (ADC) converts the output voltage, output current, and temperature into a digital signal to be transmitted via the serial interface. The ADC allows a minimum sampling frequency of 700 Hz for all three values. Monitored parameters are stored in registers (VOM, IOM, and TMON) that are continuously updated. If the Retrieve Monitoring bits in the GUI Group Configuration window shown in Figure 46 are checked, those registers are being copied into the ring buffer located in the DPM. Contents of the ring buffer can be displayed in the GUI IBS Monitoring Window shown in Figure 47 or it can be read directly via the I2C bus using high and low level commands as described in the `"DPM Programming Manual". Page 26 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Figure 45. GUI System Configuration Window ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 27 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet Figure 46. POL Group Configuration Window 9. Safety The ZY8140 POL converters do not provide isolation from input to output. The input devices powering ZY8140 must provide relevant isolation requirements according to all IEC60950 based standards. Nevertheless, if the system using the converter needs to receive safety agency approval, certain rules must be followed in the design of the system. In particular, all of the creepage and clearance requirements of the end-use safety requirements must be observed. These requirements are included in UL60950 - CSA6095000 and EN60950, although specific applications may have other or additional requirements. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com The ZY8140 POL converters have no internal fuse. If required, the external fuse needs to be provided to protect the converter from catastrophic failure. Refer to the "Input Fuse Selection for DC/DC converters" application note on www.power-one.com for proper selection of the input fuse. Both input traces and the chassis ground trace (if applicable) must be capable of conducting a current of 1.5 times the value of the fuse without opening. The fuse must not be placed in the grounded input line. Abnormal and component failure tests were conducted with the POL converter's input protected by a fast-acting 32V, 25A, fuse. If a fuse rated Page 28 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet greater than 25A is used, additional testing may be required. In order for the output of the ZY8140 POL converter to be considered as SELV (Safety Extra Low Voltage), according to all IEC60950 based standards, the input to the POL needs to be supplied by an isolated secondary source providing a SELV also. Figure 47. IBS Monitoring Window ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 29 of 30 ZY8140 40A DC-DC Intelligent POL 8V to 14V Input 0.5V to 3.65V Output Data Sheet 10. Mechanical Drawings All Dimensions are in mm Tolerances: XX.X: 0.1 XX.XX: 0.05 Figure 48. Mechanical Drawing Figure 49. Recommended Footprint - Top View Notes: 1. NUCLEAR AND MEDICAL APPLICATIONS - Power-One products are not designed, intended for use in, or authorized for use as critical components in life support systems, equipment used in hazardous environments, or nuclear control systems without the express written consent of the respective divisional president of Power-One, Inc. 2. TECHNICAL REVISIONS - The appearance of products, including safety agency certifications pictured on labels, may change depending on the date manufactured. Specifications are subject to change without notice. 2 I C is a trademark of Philips Corporation. ZD-01977 Rev. 1.1, 01-Jul-10 www.power-one.com Page 30 of 30