Single-Chip and Single-Supply Interface for

Two IBM PC/AT Serial Ports

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

Always-Active Noninverting Receiver

Output (ROUT2) Per Port

Operate Up To 250 kbit/s

Low Standby Current . . . 1 μA Typical

External Capacitors . . . 4 × 0.22 μF

Accept 5-V Logic Input With 3.3-V Supply

Allow for Flexible Power Down of Either

Serial Port

Serial-Mouse Driveability

RS-232 Bus-Pin ESD Protection Exceeds

±15 kV Using Human-Body Model (HBM)

Applications

− Battery-Powered Systems, Notebooks,

Laptops, Palmtop PCs, and Hand-Held

Equipment

description/ordering information

The SN65C23243 and SN75C23243 consist of

two ports, each containing three line drivers and

five 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. This

combination of drivers and receivers matches that needed for two typical serial ports used in an IBM PC/AT, or

compatible. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V

supply. In addition, these devices include an always-active noninverting output (ROUT2) per port, which allows

applications using the ring indicator to transmit data while the devices are powered down. The devices operate

at data signaling rates up to 250 kbit/s and a maximum of 30-V/μs driver output slew-rate.