MAX3221/MAX3223/MAX3243 +3V to +5.5V RS-232
Transceivers with AutoShutdown General Description Benefits and Features 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 deliver true RS-232 performance from a single +3.0V to
+5.5V supply. • Integrated Charge Pump Circuitry Simplifies Power 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 complementary always-active receiver for external monitoring
in a variety of 28 pin packages. Please see order
information table for package offerings. Applications