Texas Instruments
Texas Instruments MAX3232CDR RS-232 transceiver, full duplex, 2/2 drivers/receivers, 250 kbps data rate, 3 V to 5.5 V supply, 16-SOIC package, 0°C to 70°C operating temperature.
MOQ 1 · Tape & Reel (TR); Cut Tape (CT) · RoHS · EIA-481 · DAP/DDP · T/T
| Parameter / Attribute | Specification / Value |
|---|---|
| Type | Transceiver |
| Mounting | Surface Mount |
| Supply voltage | 3V ~ 5.5V |
| Protocol | RS232 |
| Operating temperature | 0°C~70°C |
| Duplex | Full |
| Package | Tape & Reel (TR); Cut Tape (CT) |
| Data rate | 250kbps |
| Case | 16-SOIC (0.154\", 3.90mm Width) |
| Receiver hysteresis | 300 mV |
| Number of drivers (Receivers) | 2/2 |
Package: DIP-16 / SOIC-16 · Pin-compatible replacements with immediate Shenzhen spot stock
The MAX232 is the chip that taught two generations of engineers what a charge pump does: a 5V RS-232 transceiver that generates its own positive and negative rails for the serial port with four capacitors and nothing else. Its long life produced three capacitor generations that get mixed freely at the bench - the original MAX232 with 1uF caps, the MAX232A at 0.1uF, and the MAX3232 which is pin-compatible, runs from 3.3V as well, and draws a tenth of the current. The substitution works in the good direction almost always; the failure mode is fitting 0.1uF caps to a genuine original MAX232 and wondering why the port is dead.
The 0.1uF Generation
Shenzhen Spot Stock (24-48h Dispatch)
The second-generation die: same pinout and function, faster charge pump, higher slew rate (200kbps class), designed around 0.1uF capacitors instead of 1uF.
5V supply with the same internal +/-rail generation; verify the rail voltages at pins 2 and 6 after fitting (about +9V and -9V on a working part).
3.3V Capable, 10x Lower Current
Shenzhen Spot Stock (24-48h Dispatch)
The modern member: 3.0V to 5.5V supply (works from 3.3V logic rails directly), 0.1uF caps, supply current in the 0.3mA class against about 5mA for the original.
3.0V to 5.5V - fits both 5V legacy and 3.3V boards; the RS-232 side still meets the +/-5V output requirement.
The Second-Source Row
Shenzhen Spot Stock (24-48h Dispatch)
The classic second-source generation of the MAX232 function: ICL232, ST232, SP232, ADM232 and HIN232 all occupy the same DIP-16 as the original.
5V supply; capacitor generation varies by vendor - older second sources want 1uF, so read the datasheet of the exact part fitted.
Q: Can I replace a MAX232 with a MAX3232?
A: Yes - pin-identical drop-in that adds 3.3V capability and cuts supply current about tenfold. Use 0.1uF capacitors and check the C3 wiring figure; the RS-232 side still meets the +/-5V output requirement.
Q: Why did my MAX232 stop working after a capacitor change?
A: Likely a capacitor-generation mismatch: the original MAX232 needs 1uF charge-pump caps, while MAX232A/MAX3232 use 0.1uF. Verify the die fitted, match the caps to it, and confirm the rails at pins 2 and 6 (about +9V and -9V).
Q: What is the difference between MAX232 and MAX232A?
A: The A is the second-generation die: same pinout and function but faster charge pump and higher slew rate, designed around 0.1uF capacitors against 1uF for the original. The A works in every MAX232 socket; the reverse needs the original capacitors restored.
The 250 kbps data rate covers standard serial port speeds up to 115200 baud with margin; if your application needs 1 Mbps or faster, this is not the part.
The internal charge pump generates the RS-232 voltage levels from the single supply rail, so no external ±12 V supply is needed. Receiver hysteresis is 300 mV, which helps reject noise on longer cable runs.
