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 0.1F 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.