MC34118-D28-T UTC [Unisonic Technologies], MC34118-D28-T Datasheet - Page 9

• Manufacturer Part Number: MC34118-D28-T
• Description: VOICE SWITCHED SPEAKER-PHONE CIRCUIT
• Manufacturer: UTC [Unisonic Technologies]

MC34118
AGC
V
the transmit and receive gains remains constant.
ATTENUATOR CONTROL BLOCK
This block has the seven:
* C1: The output of the comparator operated by RLO2 and TLO2 (here means in microphone/ speaker side).
* C2: The output of the comparator operated by RLO1 and TLO1 (here means Tip/ Ring side).
* C3: The output of the transmit background noise monitor.
* C4: The output of the receive background noise monitor.
* Volume control
* Dial tone detector
* AGC circuit
The C1~C4 effect is as follows:
Switching to the full transmit or receive from any other mode is at the fast rate (~30 ms).
X :Don’t care
Y :C3,C4 are not both 0
CC
is less than 3.5v. As while as V
The AGC circuit only affects the circuit under such situation: when the circuit is in the receive mode, and when
FUNCTIONAL DESCRIPTION(Cont.)
C1
T
T
R
R
T
T
R
R
X
X
X
X
X
X
X
X
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
C2
R
R
R
R
T
T
T
T
X
X
X
X
X
X
X
X
CC
falls below 3.5 volts, the transmit path attenuation changes so that the sum of
INPUTS
C3
Y
Y
X
X
1
0
0
0
LINEAR INTEGRATED CIRCUIT
C4
X
Y
Y
X
1
0
0
0
Slow Idle Mode
Slow Idle Mode
Slow Idle Mode
Slow Idle Mode
Transmit Mode
Fast Idle Mode
Fast Idle Mode
Receive Mode
OUTPUT
QW-R108-007,D
9 of 12