MC34118 Unisonic Technologies, MC34118 Datasheet - Page 3

• Manufacturer Part Number: MC34118
• Description: Voice Switched Speaker Phone Circuit
• Manufacturer: Unisonic Technologies

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UTC MC34118 LINEAR INTEGRATED CIRCUIT
PIN CONFIGURATIONS
UTC
PIN NAME
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
1
2
3
4
5
6
7
8
9
HTO+ Output of the second hybrid amplifier. The gain is internally set at -1 to provide a differential output, in
TLO2 Output to the transmit level detector on the microphone/ speaker side, and input to the transmit
RLO2 Output of the receive level detector on the microphone/ speaker side
TLO1 Output to the transmit level detector on the line side, and input to the transmit background monitor.
RLO1 Output of the receive level detector on the line side.
HTO- Output of the first hybrid amplifier. The gain of the amplifier is set by external resistors.
MCO Output of the microphone amplifier. The gain of the amplifier is set by external resistors.
MUT
RXO
GND
TXO
CPT
TLI2
RLI2
TLI1
RLI1
CPR
MCI
VLC
Vcc
RXI
HTI
TXI
FO
CD
CT
VB
FI
Filter Output. Output impedance is less than 50 ohms.
Filter Input. Input impedance is greater than 1 M ohms.
Chip Disable. A logic low (<0.8V) sets normal operation. A logic high (>2V) disable the IC to converse
power. Input impedance is nominally 90 K ohms.
A supply voltage of +2.8V to +6.5V is required at 5mA. As Vcc falls from 3.5V to 2.8V, an AGC circuit
reduces the receive attenuator gain by 25dB( when in the receive mode).
conjunction with HTO-, to the hybrid transformer.
Input and summing node for the first hybrid amplifier. DC lever is about equal to VB.
Output of the transmit attenuator. DC level is about VB.
Input of the transmit attenuator. Maximum signal level is 350 mVrms. Input impedance is 10KΩ.
Input of the summing node of the microphone. DC lever is VB.
Mute input. A logic low (<0.8V) sets normal operation. A logic high (>2V) mutes the microphone
amplifier without affecting the rest of the circuit. Input impedance is 90 K ohms.
Volume control input. When VLC=VB, the receive attenuator is at maximum gain when in the receive
mode. When VLC=0.3dB, the receive gain is down 35dB. Does not effect the transmit modes.
The RC at this pin sets the response time for the circuit to switch modes.
N output voltage=Vcc/2. This voltage is a system AC ground and biases the volume control. A filter
capacitor is required.
The RC at this pin sets the time constant for the transmit background side.
Input to the transmit level detector on the microphone/ speaker side.
background monitor.
Input to the receive level detector on the microphone/ speaker side
Input to the receive attenuator and dial tone detector. Maximum input level is 350mVrms. Input
impedance is 10KΩ.
Output of the receive attenuator. DC level is VB.
Input to the transmit level detector on the line side.
Input to the receive level detector on the line side.
The RC at this pin sets the time constant for the receive background monitor.
Ground pin for the entire IC.
UNISONIC TECHNOLOGIES CO., LTD.
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DESCRIPTION
QW-R108-007,B
3