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.