The MAX232AESE+T is the E-grade (extended temperature) variant of Maxim's high-speed MAX232A RS-232 transceiver, qualified across the full -40°C to +85°C industrial range. Where the commercial C-grade tops out at +70°C, this E-grade keeps RS-232 links reliable in cold-start, outdoor and high-ambient enclosures - making it the part to specify when board temperature is not controlled.

Functionally it is the same proven circuit: two transmitters, two receivers and an integrated dual charge pump that generates ±10V from a single +5V rail. As an A-grade device it is guaranteed to 200kbps and uses compact 0.1µF capacitors, so the only practical change versus a standard MAX232 design is the wider temperature window and faster data.

Because it shares the universal MAX232 16-pin pinout, the MAX232AESE is a straight drop-in for designs that need to survive the extended industrial range. Typical homes are factory-floor controllers, outdoor telemetry, transport electronics and instrumentation that see ambient swings well beyond the commercial band.

Note: Refer to the official Maxim MAX220-MAX249 datasheet for full electrical parameters. Subject to change without notice; verify all parameters before final design.

The MAX232AESE+T is supplied in a 16-pin SO package, indicated by the ESE suffix (E = extended-temperature grade). It uses the industry-standard MAX232 16-pin footprint, so the extended-temp part drops into existing RS-232 layouts unchanged.

The "+" suffix indicates lead-free, RoHS-compliant finish and the "T" suffix tape-and-reel packing. Standard 16-lead SO land patterns and reflow profiles apply; place the four 0.1µF charge-pump capacitors (C1-C4) close to the device and bypass VCC. The diagram below shows the typical operating circuit (the figure covers MAX220/MAX232/MAX232A; use the 0.1µF column for the MAX232A).

The MAX232AESE uses the classic MAX232 16-pin RS-232 pinout (top view):

• Pin 1 - C1+ / Pin 3 - C1- / Pin 4 - C2+ / Pin 5 - C2-: Charge-pump capacitor connections.
• Pin 2 - V+ / Pin 6 - V-: Charge-pump outputs (+10V / -10V).
• Pin 11 - T1IN / Pin 10 - T2IN: Driver (transmitter) TTL/CMOS inputs.
• Pin 14 - T1OUT / Pin 7 - T2OUT: Driver RS-232 outputs.
• Pin 13 - R1IN / Pin 8 - R2IN: Receiver RS-232 inputs.
• Pin 12 - R1OUT / Pin 9 - R2OUT: Receiver TTL/CMOS outputs.
• Pin 15 - GND / Pin 16 - VCC: Ground and +5V supply.

Connect C1-C4 (0.1µF), route T_IN/R_OUT to the UART and T_OUT/R_IN to the RS-232 connector. Across the full -40°C to +85°C range the same connections apply. Confirm the exact pin assignment against the datasheet image below before layout.

The following parts are listed for reference. Verify temperature grade, data rate and package before substituting.

Maxim Integrated, now part of Analog Devices (NASDAQ: ADI), originated the industry-standard MAX232 RS-232 family and offers it across commercial, extended and automotive temperature grades. The MAX232AESE extended-temperature, high-speed grade serves rugged industrial and outdoor designs.

Maxim/ADI provides complete datasheets, application notes and long-term supply, with authorized distribution and technical support across China for both prototype and volume programs.