MAX3221CAE

MAX3221CAE is Maxim’s single-channel RS-232 transceiver (one driver and one receiver). It bridges a microcontroller’s TTL/CMOS UART to RS-232 lines and back, enabling a MCU to talk to PCs, modems, or other RS-232 devices. It runs from a single supply of 3.0 V to 5.5 V and uses an internal charge pump to generate RS-232 voltage levels, so no external +/- rails are needed. The device typically requires a few external capacitors for the pump and is offered in compact 8-pin packages. The CAE suffix denotes a specific variant (package/temperature grade) in the MAX3221 family—check the datasheet for exact details. Key advantages: simple, low-power RS-232 interface with minimal external parts. Typical use cases: MCU-to-PC serial links, data loggers, serial peripherals, modems.

Equivalent products are other dual RS-232 transceivers (2 drivers, 2 receivers) in 3–5.5 V. Typical substitutes:
- TI MAX3232/MAX232
- Analog Devices ADM232
- Renesas/Intersil SP3222/SP3223
- STMicroelectronics ST3232
In practice, any 2-channel RS-232 transceiver with similar voltage and speed specs can replace MAX3221CAE.

MAX3221CAE features (single-channel RS-232 transceiver):
- 1 transmitter and 1 receiver (single-channel RS-232 transceiver)
- Operates from a single 3V to 5.5V supply
- On-chip charge-pump voltage generator; external capacitors required (typ. 1 µF each)
- TTL/CMOS-compatible input/output levels
- RS-232 voltage swing typically ±6V to ±7V
- Standard RS-232 data rates up to about 115.2 kbps
- Low quiescent current for better battery life
- EIA/TIA-232C compliant
- Small 8-pin package; CAE suffix denotes extended temperature variant (industrial range: -40°C to +85°C)
- Suitable for surface-mount or through-hole applications (depending on package).

- Pin count: 16 pins (SOIC/SSOP package).
- Function: Dual RS-232 transceiver (two drivers and two receivers) with an internal charge-pump. It converts TTL/CMOS UART signals to RS-232 voltage levels and RS-232 signals back to TTL/CMOS.

Manufacturer: Maxim Integrated Products (now part of Analog Devices, Inc., ADI).
About the company: Maxim is an American multinational semiconductor company that designs and manufactures analog and mixed-signal integrated circuits.

MAX3221CAE comes in an 8-pin SOIC package.