The Intersil ICL3221EM devices are 3.0V powered RS-232
transmitters/receivers which meet ElA/TIA-232 and
V.28/V.24 specifications. Additionally, they provide ±15kV
ESD protection (IEC61000-4-2 Air Gap and Human Body
Model) on transmitter outputs and receiver inputs (RS-232
pins). Targeted applications are PDAs, Palmtops, and
notebook and laptop computers where the low operational,
and even lower standby, power consumption is critical.
Efficient on-chip charge pumps, coupled with manual and
automatic power-down functions, reduce the standby
supply current to a 1µA trickle. Small footprint packaging,
and the use of small, low value capacitors ensure board
space savings as well. Data rates greater than 250kbps are
guaranteed at worst case load conditions. The device is fully
compatible with 3.3V-only systems.
The ICL3221EM features an automatic power-down
function which powers down the on-chip power-supply
and driver circuits. This occurs when an attached
peripheral device is shut off or the RS-232 cable is
removed, conserving system power automatically
without changes to the hardware or operating system.
These devices power up again when a valid RS-232
voltage is applied to any receiver input.
Table 1 summarizes the features of the ICL3221EM.

Features
• ESD Protection for RS-232 I/O Pins to ±15kV
(IEC61000)
• Drop in Replacement for MAX3221E
• RS-232 Compatible with VCC = 2.7V
• Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V
• Latch-Up Free
• On-Chip Voltage Converters Require Only Four External
0.1µF Capacitors
• Manual and Automatic Power-down Features
• Receiver Hysteresis For Improved Noise Immunity
• Guaranteed Minimum Data Rate . . . . . . . . 250kbps
• Power Supply Range. . . . . . . Single +3.0V to +3.6V
• Low Supply Current in Power-down State . . . . . . 1µA
• Pb-Free (RoHS Compliant)

Applications
• Any System Requiring RS-232 Communication Ports
- Battery Powered, Hand-Held, and Portable
Equipment
- Laptop Computers, Notebooks, Palmtops
- Modems, Printers and other Peripherals
- Digital Cameras
- Cellular/Mobile Phones