1 Features
• Operates With 3-V to 5.5-V VCC Supply
• Always-Active Noninverting Receiver Output
(ROUT2B)
• Low Standby Current: 1 μA Typical
• External Capacitors: 4 × 0.1 μF
• Accepts 5-V Logic Input With 3.3-V Supply
• Inter-Operable With SN65C3238, SN75C3238
• Supports Operation From 250 kbit/s to
1 Mbit/s
• RS-232 Bus-Pin ESD Protection Exceeds
±15 kV Using Human-Body Model (HBM)

2 Applications
• Battery-powered systems
• Personel electronics
• Notebooks
• Laptops
• Palmtop PCs
• Hand-held equipment

3 Description
The SN65C3243 and SN75C3243 consist of three
line drivers, five line receivers, and a dual chargepump
circuit with ±15-kV ESD protection pin to
pin (serial-port connection pins, including GND).
This device 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. In addition, this device includes an
always-active noninverting output (ROUT2B), which
allows applications using the ring indicator to transmit
data while the device is powered down. The device
operates at data signaling rates up to 1 Mbit/s and an
increased slew-rate range of 24 V/μs to 150 V/μs.