Meet or Exceed the Requirements of
TIA/EIA-232-F and ITU Recommendation
V.28
Low Supply Current . . . 420 mA Typ
Preset On-Chip Input Noise Filter
Built-in Input Hysteresis
Response and Threshold Control Inputs
Push-Pull Outputs
Functionally Interchangeable and
Pin-to-Pin Compatible With
Texas Instruments SN75189/SN75189A and
Motorola MC1489/MC1489A
Package Options Include Plastic
Small-Outline (D) and Shrink Small-Outline
(DB) Packages, and Standard Plastic (N)
DIP

description
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, compared with 0.97 V for the SN75C189A. Each receiver has
provision for adjustment of the overall input threshold levels. This is achieved by choosing external series
resistors and voltages to provide bias levels for the response-control pins. The output is in the high logic state
if the input is open circuit or shorted to ground.
These devices have an on-chip filter that rejects input pulses of less than 1-ms duration. An external capacitor
can be connected from the control pins to ground to provide further input noise filtering for each receiver.
The SN75C189 and SN75C189A have been designed using low-power techniques in a bipolar technology. In
most applications, these receivers interface to single inputs of peripheral devices such as UARTs, ACEs, or
microprocessors. By using sampling, such peripheral devices usually are insensitive to the transition times of
the input signals. If this is not the case, or for other uses, it is recommended that the SN75C189 and SN75C189A
outputs be buffered by single Schmitt input gates or single gates of the HCMOS, ALS, or 74F logic families.
The SN75C189 and SN75C189A are characterized for operation from 0°C to 70°C.