Single IC and Single 5-V Supply Interface

for Serial Communication Ports

Meets or Exceeds the Requirements of

ANSI Standards EIA/TIA-232-E-1991,

EIA/TIA-562, and ITU Recommendation V.28

Switched-Capacitor Voltage Converter

Eliminates Need for ±12-V Supplies

Voltage Converter Operates With Low

Capacitance . . . 0.1 mF Min

Designed for Data Rates up to 120 kb/s

Over 3-m Cable

Available in Shrink Small-Outline 25-mil-

Pitch Package

Shutdown Mode to Save Power When Not

in Use

±30-V Receiver Input Voltage Range

LinBiCMOSE Process Technology

Applications

– Laptop or Notebook Computers

– Portable Terminals

– Single-Board Computers

– Portable Test Equipment

description

The SN75LBC187 is a low-power LinBiCMOSE device containing three drivers, five receivers, and a

switched-capacitor voltage converter. The SN75LBC187 provides a single chip and single 5-V supply interface

between the asynchronous communications element and the serial port connector of the data terminal

equipment (DTE). This device has been designed to conform to ANSI Standards EIA/TIA-232-E, EIA/TIA-562,

and ITU recommendation V.28.

The switched-capacitor voltage converter of the SN75LBC187 uses four small external capacitors to generate

the positive and negative voltages required by EIA/TIA-232-E (and V.28) line drivers from a single 5-V input.

The drivers feature output slew-rate limiting to eliminate the need for external filter capacitors. The receivers

can accept ±30 V without damage. The device also features a reduced power or shutdown mode that cuts the

quiescent power to the IC when not transmitting data between the CPU and peripheral.

The SN75LBC187 has been designed using LinBiCMOSE technology and cells contained in the Texas

Instruments LinASICE library. The SN75LBC187 is characterized for operation from 0°C to 70°C.