TP5700A Datasheet, PDF (1/8 Pages) National Semiconductor (TI) – Telephone Speech Circuit

December 1989
TP5700A
Telephone Speech Circuit
General Description
The TP5700A is a linear bipolar device which includes all
the functions required to build the speech circuit of a tele-
phone It replaces the hybrid transformer compensation cir-
cuit and sidetone network used in traditional designs When
used with an electret microphone (with integral FET buffer)
and dynamic receiver superior audio linearity distortion and
noise performance are obtained Loop attenuation compen-
sation is also included
The low voltage design enables the circuit to work over a
wide range of operating conditions including long loops ex-
tension telephones and subscriber carrier applications
Operating power is derived from the telephone line
Features
Y _{5 mA – 120 mA loop operation}
Y _{Voltage swing down to 1 0V}
Y _{Electret microphone amplifier}
Y _{Receive amplifier with push-pull outputs}
Y _{Automatic gain compensation for loop length}
Y _{Sidetone impedance independent of input impedance}
Y _{DTMF interface with muting}
Y _{Voltage regulator outputs for DTMF generator etc}
Y _{Works in parallel with a standard phone on 20 mA loop}
Y _{Available in small outline surface mount package}
Simplified Block Diagram
C1995 National Semiconductor Corporation TL H 5201
TL H 5201 – 1
RRD-B30M115 Printed in U S A