FEATURES

· ESD Protection for RS-232 Bus Pins

– ±15-kV Human-Body Model (HBM)

– ±8-kV IEC 61000-4-2, Contact Discharge

– ±15-kV IEC 61000-4-2, Air-Gap Discharge

· Meet or Exceed the Requirements of

TIA/EIA-232-F and ITU v.28 Standards

· Operate With 3-V to 5.5-V VCC Supply

· Operate up to 1000 kbit/s

· Two Drivers and Two Receivers

· Low Standby Current . . . 1 mA Typ

· External Capacitors . . . 4 ´ 0.1 mF

· Accepts 5-V Logic Input With 3.3-V Supply

APPLICATIONS

· Battery-Powered Systems

· PDAs

· Notebooks

· Laptops

· Palmtop PCs

· Hand-Held Equipment

DESCRIPTION/ORDERING

INFORMATION

The SN65C3223E and SN75C3223E consist 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).

These devices meet the requirements of

TIA/EIA-232-F and provide 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 devices operate at

typical data signaling rates up to 1000 kbit/s.

Flexible control options for power management are available when the serial port is inactive. The

auto-powerdown feature functions when FORCEON is low and FORCEOFF is high. During this mode of

operation, if the devices do 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 devices are 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 ms. INVALID is low (invalid data) if the receiver input voltage is between –0.3 V and 0.3 V for more than

30 ms. Refer to Figure 4 for receiver input levels.