The LT 1381 is a dual RS232 driver/receiver pair with integral charge pump to generate RS232 voltage levels from a single 5V supply. The circuit features rugged bipolar design to provide operating fault tolerance and ESD protection unmatched by competing CMOS designs. Using only 0.1F external capacitors, the circuit consumes only 40mW of power and can operate to 120kbaud even while driving heavy capacitive loads. New ESD structures on the chip allow the LT1381 to survive multiple 10kV strikes, eliminating the need for costly TransZorbs on the RS232 line pins. Driver outputs are protected from overload and can be shorted to ground or up to 25V without damage. During power-off conditions, driver and receiver outputs are in a high impedance state, allowing line sharing.