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.