R1202x Series PWM Step-up DC/DC Converter for White LED/PMOLED and General Use with shutdown function The R1202x Series are CMOS-based PWM step-up DC/DC converters, which are optimized to drive white LEDs and PMOLED with constant current. There are two types. The A/B versions are optimized for the general use or the drive of PMOLED, and the D version is optimized for the serial drive of white LED with constant current. The R1202x includes an under-voltage lockout circuit (UVLO), a soft-start circuit, and an over-voltage protection circuit (OVP), a thermal shutdown circuit. By simply using an inductor, divider resistors, and capacitors as external components, PMOLED and white LEDs can be driven with high efficiency. At the standby mode, the internal NPN transistor can separate the output from the input. (Shutdown function) The A/B version with auto-discharge function is selectable. D Version can set the LED current with feedback resistor (R1). The brightness of the LEDs and the soft-start time can be adjusted by applying a PWM signal (200Hz to 300kHz) to the CE pin. In addition to DFN1616-6B, 0.95mm thickness TSOT-23-6 is available. FEATURES * Supply Current (IDD) ***************************** Typ. 800A (No switching) * Standby Current (Istandby)*********************** Max. 5A (CE="L") * Input Voltage Range (VIN) ******************** 2.3V to 5.5V (A/B Version) * Coil-current Limit Circuit *****************Current Limit Typ. 350mA / Typ. 700mA selectable * Over Voltage Protection Circuit (OVP) * Soft Start Time (tstart) ***********************Typ. 2ms (A/B Version) 1.8V to 5.5V (D Version) ********************** 1.0V (A/B Version) 0.2V (D Version) Feedback Voltage Accuracy **************** 15mV (A/B Version) 10mV (D Version) Oscillator Frequency (fosc)******************** 1.2MHz Oscillator Maximum Duty Cycle (Maxduty)******** Min. 86%, Typ. 91% UVLO Detect Voltage (VUVLO) ************** Typ. 2.0V (A/B Version) Typ. 1.6V (D Version) * Feedback Voltage (VFB) * * * * * * * * * Controllable by PWM signal to the CE pin (D Version) Thermal Shutdown Circuit **************Stops at 150C Auto-discharge Function*****************A Version Shutdown Function LED High-speed Dimming Control *******D Version Packages ****************************************DFN1616-6B, TSOT-23-6 BLOCK DIAGRAMS R1202xxxxA R1202xxxxB R1202xxxxD (With Auto-discharge function, VFB=1.0V) (Without Auto-discharge function, VFB=1.0V) (Without Auto-discharge function, VFB=0.2V) VFB VIN LX VFB VOUT VIN UVLO Q Vref Slope Compensation Driver Control R Current Sense Chip Enable OVP Slope Compensation OSC OVP EN Current Limit Slope Compensation Shutdown delay Current Sense Thermal Shutdown Part No. R1202L.x$.1. -TR DFN1616-6B 5,000 pcs R1202L.y$.1.# -TR R1202N.x$.3. -TR-FE TSOT-23-6 3,000 pcs R1202N.y$.3.# -TR-FE R1202xxxxA/B C1 1F C1 1F VIN C3 GND 4 5 6 GND VIN VOUT 1 2 3 CE VOUT VIN GND VFB R1202N713D 5LEDs (10H) 5 2 4 3 4 5 6 ) The tab is substrate level (GND). LX VOUT VFB R1 10 TYPICAL CHARACTERISTICS Lx GND VFB Efficiency (%) 1 3 R3 CE C2 1F R1 2 VOUT R2 TSOT-23-6 6 C2 0.22F VIN LX CE PACKAGES (Top View) 4 R1202xxxxD L1 10H to 22H L1 10H to 22H .x. : Specify the OVP voltage. (.3.) 14V, (.4.) 17V, (.5.) 19V, (.6.) 21V, (.7.) 23V .y. : Specify the OVP voltage. (.3.) 14V, (.7.) 23V .$. : Specify the Coil Current limit. (.1.) Typ. 350mA, (.2.) Typ. 700mA . : (.A.) with auto-discharge function, VFB=1.0V. (.B.) without auto-discharge function, VFB=1.0V. .#. : (.D.) without auto-discharge function, VFB=0.2V. 5 GND TYPICAL APPLICATIONS Q'ty per Reel DFN1616-6B CE GND Efficiency vs. Output Current 5LEDs (22H) 90 90 85 85 80 80 Efficiency (%) Package CE VFB Lx PWM Cntrl Thermal Shutdown Chip Enable CE SELECTION GUIDES 1 2 3 Current Sense GND 1 Current Limit Chip Enable CE 6 Driver Control Q S OSC Halogen Free R Vref Vref Soft Start Thermal Shutdown VOUT Switch Control PWM Comp. Driver Control Q S OVP Current Limit LX Error Amp. Switch Control PWM Comp. OSC Soft Start VIN UVLO Error Amp. Switch Control PWM Comp. S VFB VOUT UVLO Error Amp. R LX 75 70 65 VIN=5.0V VIN=4.2V VIN=3.6V VIN=3.0V 60 55 50 0 5 10 15 Output Current IOUT (mA) 75 70 65 VIN=5.0V VIN=4.2V VIN=3.6V VIN=3.0V 60 55 20 50 0 5 10 15 Output Current IOUT (mA) 20 APPLICATIONS * PMOLED power supply for hand-held equipment No.EK-255-121001 * White LED backlight for hand-held equipment Step-up DC/DC Converter R1202x Series Step-up DC/DC Converter PWM Step-up DC/DC Converter for White LED/PMOLED and General Use with shutdown function R1202x Version Lineup Product Name Application VFB Voltage Input Voltage Range OVP Voltage Function Output Capacitor Comment R1202xxxxA/B PMOLED, General Use 1.0V 2.3V to 5.5V Select from 14V, 17V, 19V, 21V, 23V Thermal Shutdown Circuit Shutdown Function Auto-discharge Function 1F to 4.7F The Method of Output Voltage Setting R1202xxxxD White LED (Serial drive) 0.2V 1.8V to 5.5V Select from 14V, 23V Thermal Shutdown Circuit Shutdown Function LED High-speed Dimming Control 0.22F to 1F LED Current setting When CE pin input is "H" (Duty=100%), LED current can be set with feedback resistor (R1). Output Voltage= (R1+ R2) / R1 L1 10H L1 10H ILED=0.2 / R1 C1 1F C1 1F VIN CE VOUT C3 R2 GND C2 0.22F VIN LX R3 C2 1F CE GND V FB R1 The total value of R1 and R2 should be equal or less than 300k. Voltage rating of capacitor (C2) is recommended to use 1.5 times or more the output setting voltage. Soft-Start Time The soft start time is set to Typ. 2ms within the IC. LX VOUT V FB R1 10 LED Dimming Control The LED brightness can be controlled by inputting the PWM signal to the CE pin. The current of LEDs when High-Duty of the CE input is "Hduty" reaches the value as in next formula. ILED=Hduty x VFB / R1 The frequency of the PWM signal is using the range between 200Hz to 300kHz. When controlling the LED brightness by the PWM signal of 20kHz or less, the increasing or decreasing of the inductor current might be make a sounds in the hearable sound wave area. In that case, please use the PWM signal in the high frequency area. In case of 6 lights or more, we recommends the R1205x Series and R1218x Series*. More than 5 lights of R1218x Series requires an external diode and OVP Voltage is set up to 31.5V. (Maximum rating of VOUT pin is 34V) ) For detail, please check our website. The currently available information as of October 2012 is provided in this New Product News. EK-255-121001