FEATURES
Controlled Baseline
– One Assembly/Test Site, One Fabrication
Site
Extended Temperature Performance of -55°C
to 125°C
Enhanced Diminishing Manufacturing
Sources (DMS) Support
Enhanced Product-Change Notification
Qualification Pedigree (1)
Single-Chip and Single-Supply Interface
for IBM™ PC/AT™ Serial Port
RS-232 Bus-Pin ESD Protection Exceeds
±15 kV Using Human-Body Model (HBM)
D 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
Three Drivers and Five Receivers
Low Standby Current . . . 1 mA Typical
External Capacitors . . . 4 ´ 0.1 mF
Accepts 5-V Logic Input With 3.3-V Supply
Always-Active Noninverting Receiver
Output (ROUT2B)
Serial-Mouse Driveability
Auto-Powerdown Feature to Disable Driver
Outputs When No Valid RS-232 Signal Is
Sensed
Applications
– Battery-Powered Systems, PDAs,
Notebooks, Laptops, Palmtop PCs, and
Hand-Held Equipment

DESCRIPTION
The MAX3243 consists of three line drivers, five line receivers, and a dual charge-pump circuit with ±15-kV ESD
(HBM) 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. This combination of drivers and receivers matches that needed for the typical serial port
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, the device includes an always-active noninverting output (ROUT2B),
which allows applications using the ring indicator to transmit data while the device is powered down.