1 Features

• ESD Protection for RS-232 bus pins

– ±15-kV Human-body model (HBM)

– ±8-kV IEC61000-4-2, Contact discharge

– ±15-kV IEC61000-4-2, Air-gap discharge

• Meets or exceeds the requirements of TIA/

EIA-232-F and ITU v.28 standards

• Operates with 3-V to 5.5-V VCC supply

• Operates up to 500 kbit/s

• Two drivers and two receivers

• Low standby current: 1 μA typical

• External capacitors: 4 × 0.1 μF

• Accepts 5-V logic input With 3.3-V supply

• Alternative high-speed pin-compatible device

(1 Mbit/s) for SNx5C3223E

2 Applications

• Battery-powered systems

• PDAs

• Notebooks

• Laptops

• Palmtop PCs

• Hand-held equipment

3 Description

The MAX3223E consists of two line drivers, two line

receivers, and a dual charge-pump circuit with ±15-kV

ESD protection pin to pin (serial-port connection pins,

including GND). The device meets the requirements

of TIA/EIA-232-F and provides the electrical interface

between an asynchronous communication controller

and the serial-port connector. The charge pump and

four small external capacitors allow operation from a

single 3-V to 5.5-V supply. The device operates at

typical data signaling rates up to 500 kbit/s and a

maximum of 30-V/μs driver output slew rate.

Flexible control options for power management are

available when the serial port is inactive. The autopowerdown

feature functions when FORCEON is

low and FORCEOFF is high. During this mode of

operation, if the device does not sense a valid RS-232

signal, the driver outputs are disabled. If FORCEOFF

is set low and EN is high, both drivers and receivers

are shut off, and the supply current is reduced to 1

mA. Disconnecting the serial port or turning off the

peripheral drivers causes auto-powerdown to occur.

Auto-powerdown can be disabled when FORCEON

and FORCEOFF are high. With auto-powerdown

enabled, the device is activated automatically when

a valid signal is applied to any receiver input. The

INVALID output is used to notify the user if an RS-232

signal is present at any receiver input. INVALID is

high (valid data) if any receiver input voltage is greater

than 2.7 V or less than –2.7 V, or has been between

–0.3 V and 0.3 V for less than 30 μs. INVALID is low

(invalid data) if the receiver input voltage is between

–0.3 V and 0.3 V for more than 30 μs. Refer to Figure

5-4 for receiver input levels.