The MAX232ACSE+T is the A-grade (high-speed) version of Maxim's industry-standard MAX232 RS-232 transceiver, part of the MAX220-MAX249 family for EIA/TIA-232E and V.28/V.24 interfaces. It provides two transmitters and two receivers with an integrated charge pump, running from a single +5V supply.

Compared with the original MAX232, the MAX232A is guaranteed to 200kbps and uses much smaller 0.1µF external capacitors instead of 1µF - saving board area and cost while supporting faster serial links. The on-chip dual charge pump (voltage doubler plus inverter) converts +5V to the ±10V required for RS-232 line levels.

Receivers translate incoming RS-232 levels to TTL/CMOS; the two independent driver/receiver pairs handle a standard TX/RX serial link. Pin-for-pin compatible with the MAX232, the MAX232A drops into existing designs and simply allows higher data rates with smaller capacitors. It operates over 0°C to +70°C in a narrow 16-pin SO.

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 MAX232ACSE+T is supplied in a narrow 16-pin SO package, indicated by the CSE suffix. It shares the industry-standard MAX232 16-pin footprint, so it drops into existing RS-232 designs (use 0.1µF capacitors for the MAX232A).

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 MAX232A 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 for the MAX232A) per the diagram, route T_IN/R_OUT to the UART and T_OUT/R_IN to the RS-232 connector. Confirm the exact pin assignment against the datasheet image below before layout.

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

Maxim Integrated, now part of Analog Devices (NASDAQ: ADI), is a leading supplier of analog and mixed-signal semiconductors and the originator of the industry-standard MAX232 RS-232 family. The MAX232A high-speed grade is widely used wherever faster RS-232 links and smaller capacitors are needed.

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.