Features

• 10mA Max Supply Current
• ESD Protection over ±10kV
• Uses Small Capacitors: 0.1µF
• 120kBaud Operation for R_L = 3k, C_L = 2500pF
• 250kBaud Operation for R_L = 3k, C_L = 1000pF
• Outputs Withstand ±30V Without Damage
• CMOS Comparable Low Power: 40mW
• Operates from a Single 5V Supply
• Rugged Bipolar Design
• Outputs Assume a High Impedance State When Off or Powered Down
• Meets All RS232 Specifications
• Available With or Without Shutdown
• Absolutely No Latch-up
• Available in SO Package

Typical Application

Description

The LT®1280A/LT1281A are dual RS232 driver/receiver pairs with integral charge pump to generate RS232 voltage levels from a single 5V supply. These circuits feature rugged bipolar design to provide operating fault tolerance and ESD protection unmatched by competing CMOS designs. Using only 0.1µF external capacitors, these circuits consume only 40mW of power, and can operate to 120kbaud even while driving heavy capacitive loads. New ESD structures on the chip allow the LT1280A/LT1281A to survive multiple ±10kV strikes, eliminating the need for costly TransZorbs® on the RS232 line pins. The LT1280A/LT1281A are fully compliant with EIA RS232 standards. Driver outputs are protected from overload, and can be shorted to ground or up to ±30V without damage. During shutdown or power-off conditions, driver and receiver outputs are in a high impedance state, allowing line sharing.

The LT1281A is available in 16-pin DIP and SO packages. The LT1280A is supplied in 18-pin DIP and SO packages for applications which require shutdown.