General Description
The MAX3221E/MAX3223E/MAX3243E are 3V-powered
EIA/TIA-232 and V.28/V.24 communications interfaces
with automatic shutdown/wakeup features, high data-
rate capabilities, and enhanced electrostatic discharge
(ESD) protection. All transmitter outputs and receiver
inputs are protected to ±15kV using IEC 1000-4-2 Air-
Gap Discharge, to ±8kV using IEC 1000-4-2 Contact
Discharge, and to ±15kV using the Human Body Model.
The MAX3221E/MAX3223E/MAX3243E achieve a
1µA supply current with Maxim’s revolutionary
AutoShutdown™ feature. They save power without
changes to the existing BIOS or operating system by enter-
ing low-power shutdown mode when the RS-232 cable is
disconnected, or when the transmitters of the connected
peripherals are off.
The transceivers have a proprietary low-dropout trans-
mitter output stage, delivering true RS-232 performance
from a +3.0V to +5.5V supply with a dual charge pump.
The charge pump requires only four small 0.1µF capaci-
tors for operation from a +3.3V supply. Each device is
guaranteed to run at data rates of 250kbps while main-
taining RS-232 output levels.
The MAX3221E contains just one driver and one receiver,
making it the smallest single-supply RS-232 transceiver.
The MAX3223E has two drivers and two receivers. The
MAX3243E is a complete 3-driver/5-receiver serial port
ideal for notebook or subnotebook computers. It also
includes two noninverting receiver outputs that are always
active, allowing external devices to be monitored without
forward biasing the protection diodes in circuitry that may
be powered down.
The MAX3221E, MAX3223E, and MAX3243E are avail-
able in space-saving TQFN, SSOP, and TSSOP pack-
ages.
Applications
Notebook, Subnotebook, and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Handheld Equipment
Peripherals
Printers
Next Generation Device Features
oFor Space-Constrained Applications:
MAX3228E/MAX3229E: ±15kV ESD-Protected, +2.5V
to +5.5V RS-232 Transceivers in UCSP™
MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E: ±15kV ESD-Protected Down to 10nA,
+3.0V to +5.5V, Up to 1Mbps, True RS-232
Transceivers (MAX3246E Available in a UCSP
Package)
oFor Data Cable Applications:
MAX3380E/MAX3381E: +2.35V to +5.5V, 1µA,
2Tx/2Rx RS-232 Transceivers with ±15kV ESD-
Protected I/O and Logic Pins
MAX3221E/MAX3223E/MAX3243E
†
±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,
RS-232 Transceivers with AutoShutdown
________________________________________________________________
Maxim Integrated Products
1
19-1283; Rev 7; 8/11
AutoShutdown and UCSP are trademarks of Maxim Integrated Products, Inc.
†
Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; 5,649,210; and other patents pending.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
*Exposed pad.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
/V
denotes an automotive qualified part.
Ordering Information continued at end of data sheet.
Ordering Information
Selector Guide
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.