MAX3221EUE

MAX3221EUE is Maxim Integrated’s RS-232 transceiver chip. It provides a single-chip interface between TTL/CMOS logic levels and RS-232 signals (driver and receiver). Key points:
- Converts TTL/CMOS TX to RS-232 levels and RS-232 RX to TTL/CMOS.
- Single-supply operation (typically 3.0–5.5 V) with an onboard charge-pump to generate RS-232 voltages, using external capacitors.
- Usually offered in small packages (e.g., 8-pin or similar) and suitable for microcontroller serial interfaces.
- Requires external charge-pump capacitors (values per datasheet; commonly around 0.1–1 µF).
- Supports RS-232 data rates suitable for typical serial links (often up to ~1 Mbps, depending on variant).
- Features like ESD protection and standard RS-232 signaling levels; easy interface to microcontrollers and UARTs.
Common uses: connecting a microcontroller to a PC serial port, modems, or other RS-232 devices. For exact pinout, voltage ranges, cap values, and performance, refer to the specific MAX3221EUE datasheet.

Equivalent RS-232 transceivers (2-channel, charge-pump) from other vendors include:
- STMicroelectronics SP3232/SP3232E
- Analog Devices ADM232/ADM3202
- Texas Instruments SN75C3220/SN75C3223
- Maxim MAX3232
Note: check pinout, supply voltage (3.3V/5V) and temperature grade for compatibility.

Here are the typical features of the MAX3221EUE RS-232 transceiver:
- 1 driver and 1 receiver (single-channel RS-232 transceiver)
- Wide supply range: operates from a single 3V to 5.5V supply
- On-chip charge-pump generator requiring four external capacitors
- Generates RS-232 level signals on TXOUT/RXIN (typical ±6V swing)
- TTL/CMOS-compatible input thresholds
- Small 8-pin package; RoHS compliant
- ESD protection on I/O pins
- Low quiescent current for battery-powered applications
- Suitable for full-duplex operation with standard RS-232 interface
Note: Exact voltage, current, and timing specifications are in the datasheet for precise design.

- Pin count: 8 pins (8-pin package).
- Function: Single-channel RS-232 transceiver with one driver and one receiver. Converts TTL/CMOS at T_IN to RS-232 at T_OUT and RS-232 at R_IN to TTL/CMOS at R_OUT, using an on-chip charge pump to generate RS-232 voltage levels from a single supply (VCC). Pin references: VCC, GND, TIN, TOUT, RIN, ROUT, V+, V-.

Manufacturer: Maxim Integrated Products, Inc. (MAXIM). Maxim is an American semiconductor company that designs and manufactures analog and mixed-signal integrated circuits. In 2021, Maxim was acquired by Analog Devices, so the MAX3221EUE is now part of Analog Devices’ product lines.

Typical application areas for MAX3221EUE:
- Embedded systems: MCU/UART to RS-232 interface
- Computer and communications: PC serial ports, modems, data-communications gear
- Industrial automation: PLCs, HMIs, sensors needing RS-232
- Networking equipment: console ports on routers/switches
- Portable/low-power devices: RS-232 at 1.8–3.3V supply
- Test, measurement, instrumentation, and point-of-sale terminals
( RS-232 transceiver with onboard charge pumps suitable for converting low-voltage logic to RS-232 levels.)

8-pin SOIC (Small Outline) package.