General Description

The MAX3233E/MAX3235E are EIA/TIA-232 and V.28/V.24 communications interfaces with automatic shutdown/wake-up features, high data-rate capabilities, and enhanced electrostatic discharge (ESD) protection. All transmitter outputs and receiver inputs are protected to ±15kV using IEC 1000-4-2 Air-Gap Discharge, to ±8kV using IEC 1000-4-2 Contact Discharge, and to ±15kV using the Human Body Model. The MAX3233E operates from a +3.3V supply; the MAX3235E operates from +5.0V.

All devices achieve a 1µA supply current using Maxim’s revolutionary AutoShutdown Plus™ feature. These devices automatically enter a low-power shutdown mode when the following two conditions occur: either the RS-232 cable is disconnected or the transmitters of the connected peripherals are inactive, and the UART driving the transmitter inputs is inactive for more than 30 seconds. They turn on again when they sense a valid transition at any transmitter or receiver input. AutoShutdown Plus saves power without changes to the existing BIOS or operating system.

Features

♦ ESD Protection for RS-232 I/O Pins

±15kV—Human Body Model

±8kV—IEC 1000-4-2, Contact Discharge

±15kV—IEC 1000-4-2, Air-Gap Discharge

♦ Latchup Free

♦ 1µA Supply Current

♦ AutoShutdown Plus—1997 EDN Magazine Innovation of the Year

♦ Single-Supply Operation

+3.0V to +3.6V (MAX3233E)

+4.5V to +5.5V (MAX3235E)

♦ 250kbps Guaranteed Data Rate

♦ 6V/µs Guaranteed Slew Rate

♦ Meets EIA/TIA-232 Specifications Down to 3.0V (MAX3233E)

♦ Internal Charge-Pump Capacitors

Applications

Subnotebook and Palmtop Computers

Cellular Phones

Battery-Powered Equipment

Hand-Held Equipment

Peripherals

Embedded Systems