MAX3221/MAX3223/MAX3243
+3V to +5.5V RS-232
Transceivers with AutoShutdown
General Description
The MAX3221/MAX3223/MAX3243 achieve 1µA supply
current with Maxim’s revolutionary AutoShutdown™
feature. When the MAX3221/MAX3223/MAX3243 do not
sense a valid signal level on their receiver inputs, the
on-board power supply and drivers shut down. This
occurs if the RS-232 cable is disconnected or if the
transmitters of the connected peripheral are turned off.
The system turns on again when a valid level is applied
to any RS-232 receiver input.
The MAX3221/MAX3223/MAX3243 require only 0.1µF
capacitors in 3.3V operation, and can operate from
input voltages ranging from +3.0V to +5.5V.
A proprietary, high-efficiency, dual charge-pump power
supply and a low-dropout transmitter combine to deliv-
er true RS-232 performance from a single +3.0V to
+5.5V supply.
The MAX3221 is a 1-driver/1-receiver 16-pin SSOP
version of the 20-pin 2-driver/2-receiver MAX3223.
The MAX3243 is a 3-driver/5-receiver with a comple-
mentary always-active receiver for external monitoring
in a variety of 28 pin packages. Please see order
information table for package offerings.
Benefits and Features
•
Integrated Charge Pump Circuitry Simplifies Power
Requirements
•
Eliminates the Need for a ±12 Supply
•
Operation From a Single +3.3V or +5V Supply
•
1µA Supply Current in Shutdown Mode Saves Power
•
AutoShutdown Feature is Enabled After No Activity
on Receiver Inputs for 30µs
•
Software Control Option for Shutdown
Ordering Information
PART
MAX3221CUE†
MAX3221EUE†
TEMP RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 SSOP
16 TSSOP
16 SSOP
16 TSSOP
20 Plastic DIP
20 SSOP
20 TSSOP
20 Plastic DIP
20 SSOP
20 TSSOP
28 Wide SO
28 SSOP
28 TSSOP
28 Wide SO
28 SSOP
28 TSSOP
Applications
•
•
•
•
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Portable Diagnostics Equipment
Selector Guide
PART
MAX3221
MAX3243
Tx
1
2
3
Rx
1
2
5
V
CC
RANGE (V) AutoShutdown
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
Yes
Yes
Yes
†
Future product—contact factory for availability.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
AutoShutdown and UCSP are trademarks of Maxim Integrated
Products, Inc.
19-0306; Rev 9; 1/15
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
