UTCMC34118 Datasheet, PDF (1/13 Pages) Unisonic Technologies – VOICE SWITCHED SPEAKER-PHONE CIRCUIT

UTCMC34118 LINEAR INTEGRATED CIRCUIT
VOICE SWITCHED
SPEAKER-PHONE CIRCUIT
DESCRIPTION
The UTC MC34118 voice switched speaker-phone
integrated circuit incorporates the necessary amplifiers,
attenuators, level detectors and control algorithm to form the
heart of a high quality hands-free speaker-phone system. It
includes a microphone amplifier with adjustable gain and
mute control. Transmit and Receive attenuators which
operate in a complementary manner, level detectors at both
input and output of both attenuators, and background noise
monitors for both the transmit and receive channels. A dial
tone detector prevents the dial tone from being attenuated by
the receive background noise monitor circuit. Also two line
driver amplifiers which can be used to form a hybrid network
in conjunction with an external coupling transformer. A
high-pass filter can be used to filter out 60Hz noise in the
receive channel, or for other filtering functions. A chip disable
pin permits powers down the entire circuit to converse power
on long loops where loop current is at a minimum. The UTC
MC34118 may be operated from a power supply, or it can be
powered from the telephone line, requiring typically 5mA. The
UTC MC34118 can be interfaced directly to TIP and
RING( through a coupling transformer) for stand-alone
operation, or it can be used in conjunction with a handset
speech network and/or other features of a feature phone.
FEATURES
*Improved attenuator gain range: 52dB between Transmit
and Receive
*Low voltage operation for line-powered applications(3~6.5V)
*4-point signal sensing for improved sensitivity
*Background noise monitors for both Transmit and Receive
paths
SOP-28
DIP-28
*Microphone amplifier gain set by external
Resistors-Mute function included
*Chip disable for active/standby operation
*On board filter pinned-out for user defined
function
*Dial tone detector to inhibit receive idle mode
during dial tone presence
ABSOLUTE MAXIMUM RATINGS(Ta=25°C,Voltages referred to pin 22)
PARAMETER
SYMBOL
VALUE
Supply Voltage
Vcc
-1~7
Voltage at Pin 3
V3
-1~Vcc+1
Voltage at Pin 12( mute)
V12
-1~Vcc+1
Voltage at Pin 13( VLC)
V13
-1~Vcc+0.5
Voltage at Pin 9, Pin 21, and Pin 2
V9, 21, 2
-0.5~Vcc+0.5
Storage temperature
Tstr
-65~150
UNIT
V
V
V
V
V
°C
UTC
UNISONIC TECHNOLOGIES CO., LTD. ¹
QW-R108-007,A