These devices are silicon gate CMOS ICs that combine both the transmitter and receiver to fulfill the electrical specifications of EIA Standard 232E and CCITT V.28. The drivers feature true TTL input compatibility, slew rate limiting outputs, 300 poweroff source impedance, and output typically switching to within 25% of the supply rails. The receivers can handle up to 25 V while presenting 3 to 7 k impedance. Hysteresis in the receivers aid in the reception of noisy signals. By combining both drivers and receivers in a single CMOS chip, these devices provide efficient, lowpower solutions for both EIA232E and V.28 applications.