Features

• Obsolete - Datasheet For Information Purposes Only.  Contact Linear Technology For Replacement
  
• Generates Full RS232 Signal Levels from 3V Supply
• 12V V_PP Output Available for Flash Memory
• Useful with a Wide Variety of Switching Regulators
• Low Supply Current: I(V_CC) = 1mA
• Wide Supply Range: 2V  V_CC  6V
• ESD Protection Over ±10kV
• Operates to 120k Baud
• Outputs Assume a High Impedance State When Off or Powered Down
• One μPower Receiver Remains Active While in SHUTDOWN
• Flowthrough Architecture Eases PC Board Layout
• 40μA Supply Current in SHUTDOWN
• Absolutely No Latch-Up
• Available in SO and SSOP Packages

Typical Application

Description

The LT1332 is a 3-driver/5-receiver RS232 transceiver, designed to be used in conjunction with a switching regulator. The LT1332 shares the regulator’s positive output, while charge is capacitively pumped from the regulator’s switch pin to the negative supply. Schottky rectifiers built into the LT1332 simplify the charge pump design.

The LT1332/LT1109A combination shown below generates fully compliant RS232 signal levels from as little as 2V of input supply. The switcher can deliver greater than 100mA of output current, making the LT1332 an excellent choice for mouse driver circuits.

Advanced driver output stages operate up to 120k baud while driving heavy capacitive loads. New ESD structures on chip make the LT1332 resilient to multiple ±10kV strikes, eliminating costly transient suppressors.

A shutdown pin disables the transceiver except for one receiver which remains active for detecting incoming RS232 signals. When shut down, the disabled drivers and receivers assume high impedance output states.