SN75C189 Overview
The SN75C189 and SN75C189A are low-power, bipolar, quadruple line receivers that are used to interface data terminal equipment (DTE) with data circuit-terminating equipment (DCE). These devices have been designed to conform to TIA/EIA-232-F. The SN75C189 has a 0.33-V typical hysteresis, pared with 0.97 V for the SN75C189A.