RS-232 transceiver for legacy and industrial serial links
The Maxim Integrated MAX231EWE+T is a full-duplex RS-232 transceiver with two drivers and two receivers, handling serial data at 120 kbps. It operates from a 5V supply or a wider 7.5V to 13.2V rail, making it a fit for both standard logic-level systems and industrial supplies that need a regulated charge-pump input. The wide-body 16-SOIC package (0.295" body width, 7.50 mm) is the footprint constraint for the PCB layout — note the 1.27 mm pitch and the clearance needed for the wide body. Temperature range is -40°C to 85°C, covering most industrial and telecom enclosures.
Supply flexibility and receiver hysteresis
The dual-supply range (5V nominal or 7.5V–13.2V) means the charge-pump can generate the RS-232 ±5V to ±15V levels from either a regulated 5V bus or a higher unregulated rail — useful in designs where the 5V rail is already loaded and you want to tap a 12V supply. The 500 mV receiver hysteresis provides noise immunity on the serial line, reducing false starts on a noisy cable. In practice, this hysteresis helps in electrically noisy environments like motor drives or factory-floor controllers where RS-232 runs a few metres outside the cabinet.
Lifecycle and sourcing
The MAX231EWE+T is listed as Active and ROHS3 compliant. For dual-sourcing, the MAX231 family includes several speed and package variants — the MAX231EWE+T is the wide-body SOIC version with 120 kbps data rate. If a pin-compatible second source is needed, the MAX232 and MAX233 families share the same 2/2 driver/receiver count and supply range but differ in charge-pump capacitor configuration and package options; verify the pinout and external capacitor count against your board before substituting.