Overview
The LA8638V provides dynamic range expansion, noise
suppression for enhancing the quality of audio signals in
cordless telephones and other communications systems.
This single chip provides the functions that make it ideal
for cordless telephones: a compressor with a logarithmic
compression ratio of 1/2, expander with a logarithmic
expansion ratio of 2, splatter filter, microphone amplifier,
BTL amplifier, waveform shaper for the receiving signal,
muting for both receiving and transmitting signals, and
standby operation.
Functions
Transmitter circuits: compressor, microphone amplifier,
limiter (IDC), muting, output level changes to user-
specified levels, and splatter filter
Receiver circuits: expander, buffer amplifier for filters,
muting, output level changes to user-specified levels,
and BTL amplifier
Other circuits: waveform shaper for the receiving signal
and standby operation
Features
Full processing of baseband signals for both receiving
and transmitting signals
Built-in BTL receiver amplifier for driving a ceramic
speaker with a load of 2 k
Standby operation that conserves battery power during
intermittent reception by disabling all but the waveform
shaper for the receiving signal
Built-in splatter filter with user-specified fc
Low-voltage operation (1.8 V to 5.5 V)
Package Dimensions
unit: mm
3191-SSOP30
Monolithic Linear IC
LA8638V
40398RM (OT) No. 5776-1/16
SANYO: SSOP30
[LA8638V]
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
Low-voltage Compander IC
for Cordless Telephones
Ordering number : EN5776
Parameter
Symbol
Conditions
Ratings
Unit
Maximum power supply voltage
V
CC
max
Pd max
7.0
V
Maximum power dissipation
Ta
≤
75°C
100
mW
Operating temperature
Topr
–20 to +75
°C
Storage temperature
Tstg
–40 to +125
°C
Specifications
Maximum Ratings
at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
Unit
Recommended power supply voltage
V
CC
V
CC
op
2.4
V
Operating power supply voltage range
1.8 to 5.5
V
Operating Conditions
at Ta = 25°C