Click here for production status of specific part numbers. MAX3222/MAX3232/ MAX3237/MAX3241* General Description The MAX3222/MAX3232/MAX3237/MAX3241 transceivers have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a 3.0V to 5.5V supply with a dual charge pump. The devices require only four small 0.1F external charge-pump capacitors. The MAX3222, MAX3232, and MAX3241 are guaranteed to run at data rates of 120kbps while maintaining RS-232 output levels. The MAX3237 is guaranteed to run at data rates of 250kbps in normal operating mode and 1Mbps in the MegaBaudTM operating mode. The MAX3222/MAX3232 have 2 receivers and 2 drivers. The MAX3222 and MAX3232 are pin, package, and functionally compatible with the industry-standard MAX242 and MAX232, respectively. The MAX3241 has 5 receivers and 3 drivers, while the MAX3237 has 3 receivers and 5 drivers. Receivers R1 (MAX3237/MAX3241) and R2 (MAX3241) have extra outputs in addition to their standard outputs. These extra outputs are always active, allowing external devices to be monitored without forward biasing the protection diodes in circuitry that may have VCC completely removed. The MAX3222, MAX3232, and MAX3241 are available in space-saving TSSOP and SSOP packages with operating temperatures of either -40C to +85C or 0C to 70C. Applications Battery-Powered Equipment Hand-Held Equipment Peripherals Datacom Equipment 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Benefits and Features Integrated Features Saves Board Space and Simplifies Design * Charge Pump Circuitry Eliminates the Need for a Bipolar 12V Supply * Wide Single-Supply Operation From +3V to +5.5V Supply * Always-On Extra Outputs Enable Monitoring of External Devices Power Saving Extends Battery Life * 1A Supply Current in Shutdown Mode While Receiver is Active (MAX3222, MAX3237, MAX3241) Ordering Information PINPACKAGE PKG CODE PART TEMP RANGE MAX3222CUP+ 0C to +70C 20 TSSOP MAX3222CAP+ 0C to +70C 20 SSOP A20+1 MAX3222CWN+ 0C to +70C 18 SO W18+1 MAX3222CPN+ 0C to +70C 18 Plastic Dip P18+5 U20+2 +Denotes lead-free package. Ordering Information continued at end of data sheet. Pin Configurations TOP VIEW EN 1 18 SHDN C1+ 2 17 VCC V+ 3 16 GND C1- 4 C2+ 5 MAX3222 15 T1OUT 14 R1IN C2- 6 13 R1OUT V- 7 12 T1IN T2OUT 8 11 T2IN R2IN 9 10 R2OUT DIP/SO Typical Operating Circuits appear at end of data sheet. Pin Configurations continued at end of data sheet. MegaBaud and UCSP are trademarks of Maxim Integrated Products, Inc. *Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending. 19-0273; Rev 8; 6/18 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Absolute Maximum Ratings VCC...........................................................................-0.3V to +6V V+ (Note 1)...............................................................-0.3V to +7V V- (Note 1)................................................................+0.3V to -7V V+ + V- (Note 1)...................................................................+13V Input Voltages T_IN, SHDN, EN..................................................-0.3V to +6V MBAUD.................................................. -0.3V to (VCC + 0.3V) R_IN.................................................................................25V Output Voltages T_OUT...........................................................................13.2V R_OUT................................................... -0.3V to (VCC + 0.3V) Short-Circuit Duration T_OUT....................................................................Continuous Continuous Power Dissipation (TA = +70C) 16-Pin TSSOP (derate 6.7mW/C above +70C).........533mW 16-Pin Narrow SO (derate 8.70mW/C above +70C).....696mW 16-Pin Wide SO (derate 9.52mW/C above +70C)....762mW 16-Pin Plastic DIP (derate 10.53mW/C above +70C)...842mW 18-Pin SO (derate 9.52mW/C above +70C)..............762mW 18-Pin Plastic DIP (derate 11.11mW/C above +70C)....889mW 20-Pin SSOP (derate 7.00mW/C above +70C).........559mW 20-Pin TSSOP (derate 8.0mW/C above +70C).........640mW 28-Pin TSSOP (derate 8.7mW/C above +70C).........696mW 28-Pin SSOP (derate 9.52mW/C above +70C).........762mW 28-Pin SO (derate 12.50mW/C above +70C)...................1W Operating Temperature Ranges MAX32_ _C_ _....................................................0C to +70C MAX32_ _E_ _ ............................................... -40C to +85C Storage Temperature Range............................. -65C to +150C Lead Temperature (soldering, 10s).................................. +300C Note 1: V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (VCC = +3.0V to +5.5V, C1-C4 = 0.1F (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS MIN TYP MAX UNITS MAX3222/MAX3232/ MAX3241 0.3 1.0 MAX3237 0.5 2.0 1.0 10 A 0.8 V DC CHARACTERISTICS VCC Power-Supply Current No load, VCC = 3.3V or 5.0V, TA = +25C Shutdown Supply Current SHDN = GND, TA = +25C mA LOGIC INPUTS AND RECEIVER OUTPUTS Input Logic Threshold Low (Note 3) T_IN, EN, SHDN, MBAUD Input Logic Threshold High (Note 3) VCC = 3.3V 2.0 VCC = 5.0V 2.4 Input Leakage Current T_IN, EN, SHDN, MBAUD 0.01 1.0 A Output Leakage Current Receivers disabled 0.05 10 A Output Voltage Low IOUT = 1.6mA 0.4 V Output Voltage High IOUT = -1.0mA VCC 0.6 V VCC - 0.1 V RECEIVER INPUTS Input Voltage Range -25 Input Threshold Low TA = +25C Input Threshold High TA = +25C www.maximintegrated.com 25 VCC = 3.3V 0.6 1.2 VCC = 5.0V 0.8 1.5 V V VCC = 3.3V 1.5 2.4 VCC = 5.0V 1.8 2.4 V Maxim Integrated 2 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Electrical Characteristics (continued) (VCC = +3.0V to +5.5V, C1-C4 = 0.1F (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS MIN Input Hysteresis Input Resistance TYP MAX 0.3 TA = +25C 3 5 UNITS V 7 k TRANSMITTER OUTPUTS Output Voltage Swing All transmitter outputs loaded with 3k to ground 5.0 5.4 V Output Resistance VCC = V+ = V- = 0V, VOUT = 2V 300 10M Output Short-Circuit Current Output Leakage Current 35 VOUT = 12V, VCC = 0V or 3V to 5.5V, transmitters disabled 60 mA 25 A MOUSE DRIVEABILITY (MAX3241) Transmitter Output Voltage T1IN = T2IN = GND, T3IN = VCC, T3OUT loaded with 3k to GND, T1OUT and T2OUT loaded with 2.5mA each 5.0 V Timing Characteristics--MAX3222/MAX3232/MAX3241 (VCC = +3.0V to +5.5V, C1-C4 = 0.1F (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS MIN TYP 120 235 MAX UNITS Maximum Data Rate RL = 3k, CL = 1000pF, one transmitter switching Receiver Propagation Delay R_IN to R_OUT, CL = 150pF Receiver Output Enable Time Normal operation 200 ns Receiver Output Disable Time Normal operation 200 ns Transmitter Skew | tPHL - tPLH | 300 ns Receiver Skew | tPHL - tPLH | 300 ns Transition-Region Slew Rate VCC = 3.3V, RL = 3k to 7k, +3V to -3V or -3V to +3V, TA = +25C, one transmitter switching www.maximintegrated.com tPHL 0.3 tPLH 0.3 kbps s CL = 150pF to 1000pF 6 30 CL = 150pF to 2500pF 4 30 V/s Maxim Integrated 3 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Timing Characteristics--MAX3237 (VCC = +3.0V to +5.5V, C1-C4 = 0.1F (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) PARAMETER CONDITIONS Maximum Data Rate MIN RL = 3k, CL = 1000pF, one transmitter switching, MBAUD = GND 250 VCC = 3.0V to 4.5V, RL = 3k, CL = 250pF, one transmitter switching, MBAUD = VCC 1000 VCC = 4.5V to 5.5V, RL = 3k, CL = 1000pF, one transmitter switching, MBAUD = VCC 1000 TYP MAX UNITS kbps tPHL 0.15 tPLH 0.15 s Receiver Propagation Delay R_IN to R_OUT, CL = 150pF Receiver Output Enable Time Normal operation 200 ns Receiver Output Disable Time Normal operation 200 ns | tPHL - tPLH |, MBAUD = GND 100 ns | tPHL - tPLH |, MBAUD = VCC 25 ns | tPHL - tPLH | 50 ns Transmitter Skew Receiver Skew CL = 150pF to 1000pF VCC = 3.3V, RL = 3 to 7k, +3V to -3V or -3V to +3V, TA = +25C Transition-Region Slew Rate MBAUD = GND 6 30 MBAUD = VCC 24 150 4 30 CL = 150pF to 2500pF, MBAUD = GND V/s Note 2: MAX3222/MAX3232/MAX3241: C1-C4 = 0.1F tested at 3.3V 10%; C1 = 0.047F, C2-C4 = 0.33F tested at 5.0V 10%. MAX3237: C1-C4 = 0.1F tested at 3.3V 5%; C1-C4 = 0.22F tested at 3.3V 10%; C1 = 0.047F, C2-C4 = 0.33F tested at 5.0V 10%. Note 3: Transmitter input hysteresis is typically 250mV. Typical Operating Characteristics (VCC = +3.3V, 235kbps data rate, 0.1F capacitors, all transmitters loaded with 3k, TA = +25C, unless otherwise noted.) MAX3222/MAX3232 SLEW RATE vs. LOAD CAPACITANCE 22 FOR DATA RATES UP TO 235kbps 20 40 35 2 1 0 -1 -2 -3 SUPPLY CURRENT (mA) 18 16 14 -SLEW 12 10 +SLEW 8 6 -4 4 VOUT- -5 0 0 1000 2000 3000 4000 LOAD CAPACITANCE (pF) www.maximintegrated.com 5000 235kbps 30 25 120kbps 20 15 20kbps 10 5 2 -6 MAX3222-03 4 3 MAX3222/MAX3232 SUPPLY CURRENT vs. LOAD CAPACITANCE WHEN TRANSMITTING DATA MAX3222-02 VOUT+ MAX3222-01 6 5 SLEW RATE (V/s) TRANSMITTER OUTPUT VOLTAGE (V) MAX3222/MAX3232 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE 0 150 1000 2000 3000 4000 LOAD CAPACITANCE (pF) 5000 0 1000 2000 3000 4000 5000 LOAD CAPACITANCE (pF) Maxim Integrated 4 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Typical Operating Characteristics (continued) (VCC = +3.3V, 235kbps data rate, 0.1F capacitors, all transmitters loaded with 3k, TA = +25C, unless otherwise noted.) MAX3241 SLEW RATE vs. LOAD CAPACITANCE 5.0 24 22 1 TRANSMITTER AT 235kbps 2 TRANSMITTERS AT 30kbps 0 -2.5 VOUT- -5.0 0 1000 2000 3000 4000 14 12 +SLEW 10 30 120kbps 25 20 20kbps 15 8 10 6 5 5000 0 1000 0 2000 3000 4000 0 5000 1000 2000 3000 4000 5000 LOAD CAPACITANCE (pF) LOAD CAPACITANCE (pF) LOAD CAPACITANCE (pF) MAX3237 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (MBAUD = GND) MAX3237 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE (MBAUD = VCC) MAX3237 SLEW RATE vs. LOAD CAPACITANCE (MBAUD = GND) 0 -2.5 -5.0 -7.5 2.5 1 TRANSMITTER AT FULL DATA RATE 4 TRANSMITTERS AT 1/16 DATA RATE 3k + CL LOAD, EACH OUTPUT VCC = 3.3V 0 -2.5 1000 2000 3000 4000 5000 4 1Mbps SUPPLY CURRENT (mA) 1 TRANSMITTER AT FULL DATA RATE 4 TRANSMITTERS AT 1/16 DATA RATE 3k + CL LOAD EACH OUTPUT VCC = 3.3V 0 2000 500 1000 1500 LOAD CAPACITANCE (pF) www.maximintegrated.com 70 2000 3000 20kbps 20 1 TRANSMITTER AT FULL DATA RATE 4 TRANSMITTERS AT 1/16 DATA RATE 3k + CL LOADS VCC = 3.3V 0 1000 2000 3000 4000 LOAD CAPACITANCE (pF) AVERAGE; 10 PARTS 30 20 0 5000 MAX 40 30 4000 1 TRANSMITTER AT 512kbps 4 TRANSMITTERS AT 32kbps 3k + CL LOADS VCC = 3.3V MBAUD = VCC 60 50 120kbps 40 1000 MAX3237 SKEW vs. LOAD CAPACITANCE (tPLH - tPHL) 240kbps 10 2000 0 LOAD CAPACITANCE (pF) MAX3222-11 50 30 0 1500 60 MAX3222-10 40 10 1000 MAX3237 SUPPLY CURRENT vs. LOAD CAPACITANCE (MBAUD = GND) -SLEW, 1Mbps +SLEW, 1Mbps -SLEW, 2Mbps +SLEW, 2Mbps 20 500 MAX3237 SLEW RATE vs. LOAD CAPACITANCE (MBAUD = VCC) 50 1 TRANSMITTER AT 240kbps 4 TRANSMITTERS AT 15kbps 3k + CL LOADS VCC = 3.3V 0 0 LOAD CAPACITANCE (pF) 60 MAX3222-09 6 2 LOAD CAPACITANCE (pF) 70 +SLEW 8 -7.5 0 -SLEW 1.5Mbps 2Mbps -5.0 10 1.5Mbps MAX3222-12 1 TRANSMITTER AT 240kbps 4 TRANSMITTERS AT 15kbps 3k + CL LOADS VCC = 3.3V 2Mbps SLEW RATE (V/s) 2.5 1Mbps 5.0 12 MAX3222-08 5.0 7.5 TRANSMITTER OUTPUT VOLTAGE (V) MAX3222-07 7.5 TRANSMITTER OUTPUT VOLTAGE (V) -SLEW 16 35 4 -7.5 SLEW RATE (V/s) 18 235kbps 40 SUPPLY CURRENT (mA) SLEW RATE (V/s) 20 2.5 45 MAX3222-05 VOUT+ MAX3222-04 TRANSMITTER OUTPUT VOLTAGE (V) 7.5 MAX3241 SUPPLY CURRENT vs. LOAD CAPACITANCE WHEN TRANSMITTING DATA MAX3222-06 MAX3241 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE 10 MIN 0 5000 0 500 1000 1500 2000 2500 LOAD CAPACITANCE (pF) Maxim Integrated 5 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Pin Description PIN MAX3222 MAX3232 MAX3237 MAX3241 NAME FUNCTION DIP/SO SSOP 1 1 -- 13 23 EN Receiver Enable. Active low. 2 2 1 28 28 C1+ Positive Terminal of Voltage-Doubler Charge-Pump Capacitor 3 3 2 27 27 V+ +5.5V Generated by the Charge Pump 4 4 3 25 24 C1- Negative Terminal of Voltage-Doubler Charge-Pump Capacitor 5 5 4 1 1 C2+ Positive Terminal of Inverting Charge-Pump Capacitor 6 6 5 3 2 C2- Negative Terminal of Inverting Charge-Pump Capacitor 7 7 6 4 3 V- 8, 15 8, 17 7, 14 5, 6, 7, 10, 12 9, 10, 11 T_OUT 9, 14 9, 16 8, 13 8, 9, 11 4-8 R_IN 10, 13 10, 15 9, 12 18, 20, 21 15-19 R_OUT TTL/CMOS Receiver Outputs 11, 12 12, 13 10, 11 17, 19, 22, 23, 24 12, 13, 14 T_IN TTL/CMOS Transmitter Inputs 16 18 15 2 25 GND Ground 17 19 16 26 26 VCC +3.0V to +5.5V Supply Voltage 18 20 -- 14 22 SHDN Shutdown Control. Active low. -- 11, 14 -- -- -- N.C. -- -- -- 15 -- MBAUD MegaBaud Control Input. Connect to GND for normal operation; connect to VCC for 1Mbps transmission rates. -- -- -- 16 20, 21 R_OUTB Noninverting Complementary Receiver Outputs. Always active. www.maximintegrated.com -5.5V Generated by the Charge Pump RS-232 Transmitter Outputs RS-232 Receiver Inputs No Connection Maxim Integrated 6 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Detailed Description The MAX3222/MAX3237/MAX3241's output stage is turned off (high impedance) when the device is in shutdown mode. When the power is off, the MAX3222/ MAX3232/MAX3237/MAX3241 permit the outputs to be driven up to 12V. Dual Charge-Pump Voltage Converter The MAX3222/MAX3232/MAX3237/MAX3241's internal power supply consists of a regulated dual charge pump that provides output voltages of +5.5V (doubling charge pump) and -5.5V (inverting charge pump), regardless of the input voltage (VCC) over the 3.0V to 5.5V range. The charge pumps operate in a discontinuous mode; if the output voltages are less than 5.5V, the charge pumps are enabled, and if the output voltages exceed 5.5V, the charge pumps are disabled. Each charge pump requires a flying capacitor (C1, C2) and a reservoir capacitor (C3, C4) to generate the V+ and V- supplies. RS-232 Transmitters The transmitters are inverting level translators that convert CMOS-logic levels to 5.0V EIA/TIA-232 levels. The MAX3222/MAX3232/MAX3241 transmitters guarantee a 120kbps data rate with worst-case loads of 3k in parallel with 1000pF, providing compatibility with PC-to-PC communication software (such as LapLinkTM). Typically, these three devices can operate at data rates of 235kbps. Transmitters can be paralleled to drive multiple receivers or mice. The transmitter inputs do not have pullup resistors. Connect unused inputs to GND or VCC. MAX3237 MegaBaud Operation In normal operating mode (MBAUD = GND), the MAX3237 transmitters guarantee a 250kbps data rate with worstcase loads of 3k in parallel with 1000pF. This provides compatibility with PC-to-PC communication software, such as LapLink. For higher speed serial communications, the MAX3237 features MegaBaud operation. In MegaBaud operating mode (MBAUD = VCC), the MAX3237 transmitters guarantee a 1Mbps data rate with worst-case loads of 3k in parallel with 250pF for 3.0V < VCC < 4.5V. For 5V 10% operation, the MAX3237 transmitters guarantee a 1Mbps data rate into worst-case loads of 3k in parallel with 1000pF. LapLink is a trademark of Traveling Software, Inc. VCC VCC 0.1F 0.1F VCC C1+ C1 C1C2+ C2 C2- C3 MAX3222 MAX3232 MAX3237 MAX3241 C2+ V- C4 C2 C2- T_ OUT 0V 5k GND V+ C3 MAX3222 MAX3232 MAX3237 MAX3241 VC4 T_ OUT R_ IN R_ OUT EN* SHDN* VCC T_ IN R_ IN R_ OUT VCC C1 C1- T_ IN 0V C1+ V+ 3k 2500pF VCC EN* 5k SHDN* GND 7k 150pF *MAX3222/MAX3237/MAX3241 ONLY MINIMUM SLEW-RATE TEST CIRCUIT MAXIMUM SLEW-RATE TEST CIRCUIT Figure 1. Slew-Rate Test Circuits www.maximintegrated.com Maxim Integrated 7 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers RS-232 Receivers The receivers convert RS-232 signals to CMOS-logic output levels. The MAX3222/MAX3237/MAX3241 receivers have inverting three-state outputs. In shutdown, the receivers can be active or inactive (Table 1). The complementary outputs on the MAX3237 (R1OUTB) and the MAX3241 (R1OUTB, R2OUTB) are always active, regardless of the state of EN or SHDN. This allows for Ring Indicator applications without forward biasing other devices connected to the receiver outputs. This is ideal for systems where VCC is set to 0V in shutdown to accommodate peripherals, such as UARTs (Figure 2). VCC PREVIOUS RS-232 VCC Rx PROTECTION DIODE 5k UART Tx GND MAX3222/MAX3237/MAX3241 Shutdown Mode SHDN = GND Supply current falls to less than 1A in shutdown mode (SHDN = low). When shut down, the device's charge pumps are turned off, V+ is pulled down to VCC, V- is pulled to ground, and the transmitter outputs are disabled (high impedance). The time required to exit shutdown is typically 100s, as shown in Figure 3. Connect SHDN to VCC if the shutdown mode is not used. SHDN has no effect on R_OUT or R_OUTB. a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE RECEIVER OUTPUT IN SHUTDOWN. VCC TO P LOGIC TRANSITION DETECTOR MAX3222/MAX3237/MAX3241 Enable Control The inverting receiver outputs (R_OUT) are put into a high-impedance state when EN is high. The complementary outputs R1OUTB and R2OUTB are always active, regardless of the state of EN and SHDN (Table 1). EN has no effect on T_OUT. MAX3237 MAX3241 R1OUTB VCC Rx R1OUT PROTECTION DIODE EN = VCC UART T1IN Tx GND R1IN T1OUT SHDN = GND b) NEW MAX3237/MAX3241: EN SHUTS DOWN RECEIVER OUTPUTS (EXCEPT FOR B OUTPUTS), SO NO CURRENT FLOWS TO UART IN SHUTDOWN. B OUTPUTS INDICATE RECEIVER ACTIVITY DURING SHUTDOWN WITH EN HIGH. Figure 2. Detection of RS-232 Activity when the UART and Interface are Shut Down; Comparison of MAX3237/MAX3241 (b) with Previous Transceivers (a). www.maximintegrated.com Applications Information Capacitor Selection 5k The capacitor type used for C1-C4 is not critical for proper operation; polarized or nonpolarized capacitors can be used. The charge pump requires 0.1F capacitors for 3.3V operation. For other supply voltages, refer to Table 2 for required capacitor values. Do not use values lower than those listed in Table 2. Increasing the capacitor values (e.g., by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be increased without changing C1's value. However, do not increase C1 without also increasing the values of C2, C3, and C4, to maintain the proper ratios (C1 to the other capacitors). When using the minimum required capacitor values, make sure the capacitor value does not degrade excessively with temperature. If in doubt, use capacitors with a higher nominal value. The capacitor's equivalent series resistance (ESR), which usually rises at low temperatures, influences the amount of ripple on V+ and V-. Maxim Integrated 8 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Table 1. MAX3222/MAX3237/MAX3241 Shutdown and Enable Control Truth Table Power-Supply Decoupling SHDN EN T_OUT R_OUT R_OUTB (MAX3237/ MAX3241) 0 0 High-Z Active Active 0 1 High-Z High-Z Active 1 0 Active Active Active 1 1 Active High-Z Active Table 2. Required Minimum Capacitor Values V CC (V) C1 (F) C2, C3, C4 (F) MAX3222/MAX3232/MAX3241 3.0 to 3.6 0.1 0.1 4.5 to 5.5 0.047 0.33 3.0 to 5.5 0.1 0.47 MAX3237 3.0 to 3.6 0.22 0.22 3.15 to 3.6 0.1 0.1 4.5 to 5.5 0.047 0.33 3.0 to 5.5 0.22 1.0 5V/div In most circumstances, a 0.1F bypass capacitor is adequate. In applications that are sensitive to powersupply noise, decouple VCC to ground with a capacitor of the same value as charge-pump capacitor C1. Connect bypass capacitors as close to the IC as possible. Operation Down to 2.7V Transmitter outputs will meet EIA/TIA-562 levels of 3.7V with supply voltages as low as 2.7V. Transmitter Outputs when Exiting Shutdown Figure 3 shows two transmitter outputs when exiting shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 levels (one transmitter input is high, the other is low). Each transmitter is loaded with 3k in parallel with 2500pF. The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that the transmitters are enabled only when the magnitude of V- exceeds approximately 3V. Mouse Driveability The MAX3241 has been specifically designed to power serial mice while operating from low-voltage power supplies. It has been tested with leading mouse brands from manufacturers such as Microsoft and Logitech. The MAX3241 successfully drove all serial mice tested and met their respective current and voltage requirements. Figure 4a shows the transmitter output voltages under increasing load current at 3.0V. Figure 4b shows a typical mouse connection using the MAX3241. T2 2V/div T1 50s/div VCC = 3.3V C1-C4 = 0.1F Figure 3. Transmitter Outputs when Exiting Shutdown or Powering Up www.maximintegrated.com Maxim Integrated 9 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers 6 5 4 3 VOUT+ VCC = 3.0V 2 1 T1 0 -1 T2 MAX3222-04 TRANSMITTER OUTPUT VOLTAGE (V) MAX3222/MAX3232/ MAX3237/MAX3241 VOUT+ -2 -3 VCC VOUT- T3 VOUT- -4 -5 -6 0 1 2 3 4 5 6 7 LOAD CURRENT PER TRANSMITTER (mA) Figure 4a. MAX3241 Transmitter Output Voltage vs. Load Current per Transmitter VCC = 3V to 5.5V 28 C1 C2 C1+ 0.1F 26 VCC V+ 27 C3 24 C11 C2+ 2 C214 T1IN COMPUTER SERIAL PORT MAX3241 V- 3 C4 T1OUT 9 13 T2IN T2OUT 10 12 T3IN T3OUT 11 +V VCC -V 21 R1OUTB GND 20 R2OUTB 19 R1OUT R1IN 4 18 R2OUT 5k R2IN 5 17 R3OUT 5k R3IN 6 16 R4OUT 5k R4IN 7 R5IN 8 15 R5OUT 23 EN +V 5k MOUSE 5k GND 25 Tx SHDN 22 Figure 4b. Mouse Driver Test Circuit www.maximintegrated.com Maxim Integrated 10 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers VCC 0.1F V+ C3 C1C2+ C2 C2- 5V/div T1OUT 5V/div R1OUT 5V/div VCC C1+ C1 T1IN MAX3222 MAX3232 MAX3237 MAX3241 VC4 5s/div VCC = 3.3V T_ OUT T_ IN Figure 6. MAX3241 Loopback Test Result at 120kbps R_ IN R_ OUT 0V VCC EN* SHDN* 5k 1000pF T1IN 5V/div T1OUT 5V/div R1OUT 5V/div GND * MAX3222/MAX3241 ONLY Figure 5. Loopback Test Circuit High Data Rates The MAX3222/MAX3232/MAX3241 maintain the RS-232 5.0V minimum transmitter output voltage even at high data rates. Figure 5 shows a transmitter loopback test circuit. Figure 6 shows a loopback test result at 120kbps, and Figure 7 shows the same test at 235kbps. For Figure 6, all transmitters were driven simultaneously at 120kbps into RS-232 loads in parallel with 1000pF. For Figure 7, a single transmitter was driven at 235kbps, and all transmitters were loaded with an RS-232 receiver in parallel with 1000pF. The MAX3237 maintains the RS-232 5.0V minimum transmitter output voltage at data rates up to 1Mbps. Figure 8 shows a loopback test result at 1Mbps with MBAUD = VCC. For Figure 8, all transmitters were loaded with an RS-232 receiver in parallel with 250pF. 2s/div VCC = 3.3V Figure 7. MAX3241 Loopback Test Result at 235kbps +5V T_IN 0V +5V T_OUT = R_IN 5k + 250pF 0V -5V +5V R_OUT 150pF 0V 200ns/div VCC = 3.3V Figure 8. MAX3237 Loopback Test Result at 1000kbps (MBAUD = VCC) www.maximintegrated.com Maxim Integrated 11 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Interconnection with 3V and 5V Logic Table 3. Logic-Family Compatibility with Various Supply Voltages The MAX3222/MAX3232/MAX3237/MAX3241 can directly interface with various 5V logic families, including ACT and HCT CMOS. See Table 3 for more information on possible combinations of interconnections. SYSTEM POWERSUPPLY VOLTAGE (V) MAX32_ _ V CC SUPPLY VOLTAGE (V) 3.3 3.3 5 5 5 3.3 COMPATIBILITY Compatible with all CMOS families. Compatible with all TTL and CMOS-logic families Compatible with ACT and HCT CMOS, and with TTL. Incompatible with AC, HC, and CD4000 CMOS. Typical Operating Circuits +3.3V +3.3V 17 0.1F C1 0.1F 2 C1+ 4 5 C2 0.1F 6 C1- V+ MAX3222 C2+ V- 3 0.1F C4 0.1F 0.1F T2OUT 8 TTL/CMOS OUTPUTS 5k 10 R2OUT R2IN 9 V+ C2+ V- GND 16 SHDN 6 C2- C4 0.1F T1OUT 14 RS-232 OUTPUTS T2OUT 7 R1IN 13 12 R1OUT TTL/CMOS OUTPUTS 5k 9 R2OUT R2IN 8 5k EN C3* 0.1F MAX3232 10 T2IN RS-232 INPUTS 2 TTL/CMOS INPUTS R1IN 14 13 R1OUT 5 C1- VCC 11 T1IN RS-232 OUTPUTS 11 T2IN 3 4 T1OUT 15 TTL/CMOS INPUTS 1 1 C1+ C3* 0.1F 7 C2- 12 T1IN 16 0.1F VCC RS-232 INPUTS 5k 18 GND 15 PIN NUMBERS REFER TO DIP/SO PACKAGES. * C3 CAN BE RETURNED TO EITHER VCC OR GROUND. * C3 CAN BE RETURNED TO EITHER VCC OR GROUND. SEE TABLE 2 FOR CAPACITOR SELECTION www.maximintegrated.com Maxim Integrated 12 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Typical Operating Circuits (continued) 0.1F +3.3V 26 0.1F 28 C1+ 3 C2+ 27 0.1F MAX3237 V- 4 23 T2IN 22 T3IN 19 T4IN T1 T2 T3 0.1F T4 T1OUT 5 T2OUT 6 T3OUT 7 28 C1+ TTL/CMOS INPUTS RS-232 OUTPUTS VCC V+ 2 C2+ MAX3241 T5 14 T1IN T1OUT 9 13 T2IN T2OUT 10 12 T3IN T3OUT 11 RS-232 OUTPUTS 21 R1OUTB 19 R1OUT R1IN 4 5k R2IN 18 R2OUT 5 R1IN 8 R1 TTL/CMOS OUTPUTS R2IN R2 9 R3IN 11 R3 RS-232 INPUTS 5k 17 R3OUT R3IN 6 16 R4OUT R4IN 7 5k 15 R5OUT MBAUD 13 EN GND SHDN RS-232 INPUTS 5k 5k R5IN 8 15 14 2 * C3 CAN BE RETURNED TO EITHER VCC OR GROUND. www.maximintegrated.com C4 0.1F T5OUT 12 5k 18 R3OUT 3 T4OUT 10 5k 20 R2OUT V- C2- 16 R1OUTB LOGIC OUTPUTS C3* 0.1F 20 R2OUTB 17 T5IN 21 R1OUT 27 24 C11 0.1F C2- 24 T1IN LOGIC INPUTS V+ 25 C11 0.1F VCC 26 0.1F 0.1F 5k 23 EN GND SHDN 22 25 * C3 CAN BE RETURNED TO EITHER VCC OR GROUND. Maxim Integrated 13 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Pin Configurations (continued) TOP VIEW EN 1 20 SHDN C1+ 2 19 VCC C1+ 1 V+ 3 18 GND V+ 2 15 GND C1- 4 17 T1OUT C1- 3 14 T1OUT C2+ 5 16 R1IN C2+ 4 C2- 6 15 R1OUT C2- 5 V- 7 14 N.C. V- 6 11 T1IN T2OUT 8 13 T1IN T2OUT 7 10 T2IN R2IN 9 12 T2IN R2IN 8 R2OUT 10 11 N.C. MAX3222 + 16 VCC MAX3232 13 R1IN 12 R1OUT 9 R2OUT DIP/SO/TSSOP SSOP/TSSOP C2+ 1 + GND 2 + C2+ 1 27 V+ C2- 2 27 V+ V- 3 26 VCC 28 C1+ 28 C1+ C2- 3 26 VCC V- 4 25 C1- R1IN 4 25 GND 24 T1IN R2IN 5 24 C1- 23 T2IN R3IN 6 22 T3IN R4IN 7 22 SHDN R1IN 8 21 R1OUT R5IN 8 21 R1OUTB R2IN 9 20 R2OUT T1OUT 9 20 R2OUTB 19 T4IN T2OUT 10 19 R1OUT 18 R3OUT T3OUT 11 18 R2OUT 17 T5IN T3IN 12 17 R3OUT 16 R1OUTB T2IN 13 16 R4OUT 15 MBAUD T1IN 14 15 R5OUT T1OUT 5 T2OUT 6 MAX3237 T3OUT 7 T4OUT 10 R3IN 11 T5OUT 12 EN 13 SHDN 14 SSOP www.maximintegrated.com MAX3241 23 EN SO/SSOP/TSSOP Maxim Integrated 14 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Ordering Information (continued) PART TEMP RANGE PINPACKAGE PKG CODE PART TEMP RANGE PINPACKAGE PKG CODE MAX3222EUP+ -40C to +85C 20 TSSOP U20+2 MAX3232EWE+ -40C to +85C 16 Wide SO W16+1 MAX3222EAP+ -40C to +85C 20 SSOP A20+1 MAX3232EPE+ -40C to +85C 16 Plastic DIP P16+1 MAX3222EWN+ -40C to +85C 18 SO W18+1 MAX3237CAI+ 0C to +70C 16 SSOP A28+2 MAX3222EPN+ -40C to +85C 18 Plastic Dip P18+5 MAX3237EAI+ -40C to +85C 28 SSOP A28+1 -- MAX3241CUI+ 0C to +70C 28 TSSOP U28+2 MAX3222C/D 0C to +70C Dice* MAX3232CUE+ 0C to +70C 16 TSSOP U16+1 MAX3241CAI+ 0C to +70C 28 SSOP A28+1 MAX3232CSE+ 0C to +70C 16 Narrow SO S16+1 MAX3241CWI+ 0C to +70C 28 SO W28+6 MAX3232CWE+ 0C to +70C 16 Wide SO W16+1 MAX3241EUI+ -40C to +85C 28 TSSOP U28+2 MAX3232CPE+ 0C to +70C 16 Plastic DIP P16+1 MAX3241EAI+ -40C to +85C 28 SSOP A28+1 MAX3232EUE+ -40C to +85C 16 TSSOP U16+1 MAX3241EWI+ -40C to +85C 28 SO W28+6 MAX3232ESE+ -40C to +85C 16 Narrow SO S16+5 *Dice are tested at TA = +25C, DC parameters only. +Denotes lead-free package. 3V-Powered EIA/TIA-232 and EIA/TIA-562 Transceivers from Maxim PART POWERSUPPLY VOLTAGE (V) NO. OF TRANSMITTERS/ RECEIVERS NO. OF RECEIVERS ACTIVE IN SHUTDOWN GUARANTEED DATA RATE (kbps) EIA/ TIA-232 OR 562 MAX212 3.0 to 3.6 3/5 5 120 232 Drives mice MAX218 1.8 to 4.25 2/2 2 120 232 Operates directly from batteries without a voltage regulator MAX562 2.7 to 5.25 3/5 5 230 562 Wide supply range MAX563 3.0 to 3.6 2/2 2 230 562 0.1F capacitors MAX3212 2.7 to 3.6 3/5 5 235 232 AutoShutdown, complementary receiver, drives mice, transient detection MAX3222 3.0 to 5.5 2/2 2 120 232 0.1F capacitors MAX3223 3.0 to 5.5 2/2 2 120 232 0.1F capacitors, AutoShutdown MAX3232 3.0 to 5.5 2/2 N/A 120 232 0.1F capacitors MAX3237 3.0 to 5.5 5/3 3 250/1000 232 0.1F capacitors, 1 complementary receiver, MegaBaud operation MAX3241 3.0 to 5.5 3/5 5 120 232 0.1F capacitors, 2 complementary receivers, drives mice MAX3243 3.0 to 5.5 3/5 1 120 232 0.1F capacitors, AutoShutdown, complementary receiver, drives mice www.maximintegrated.com FEATURES Maxim Integrated 15 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. U20+2 21-0066 90-0116 20 SSOP A20+1 21-0056 90-0094 18 SO W18+1 21-0042 90-0181 18 Plastic Dip P18+5 21-0043 -- -- -- -- U16+1 21-0066 90-0117 16 Narrow SO S16+1 21-0041 90-0097 16 Wide SO W16+1 21-0042 90-0107 20 TSSOP Dice* 16 TSSOP 16 Plastic DIP P16+1 21-0043 -- 16 Narrow SO S16+5 21-0041 90-0097 16 SSOP A28+2 21-0056 90-0095 28 SSOP A28+1 21-0056 90-0095 28 TSSOP U28+2 21-0066 90-0171 28 SO W28+6 21-0042 90-0109 28 TSSOP U28+2 21-0066 90-0171 www.maximintegrated.com Maxim Integrated 16 MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Revision History REVISION NUMBER REVISION DATE 7 1/07 General updates 1, 15, 16, 17 8 6/18 Updated Package Information and Ordering Information 1, 15, 16, 17 DESCRIPTION PAGES CHANGED For delivery, and ordering information, please visit Maxim Integrated's online storefront at https://www.maximintegrated.com/en/storefront/storefront.html. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2018 Maxim Integrated Products, Inc. 17