Panasonic KX-1T7533G Service Manual page 22

KX-T7533G/KX-T7533G-B
8. HOOK SWITCH CIRCUIT
1) Circuit Operation
Circuit Diagram
+5V(V1)
+5V(V1)
IC6
IC1@2)
2kHz Square Wave
9. HANDSET CIRCUIT
1) Transmission signal path
The analog input signal from the handset microphone is input to the communication LS! through the IC2 built-in analog
amplifier. In this LS! the network contro! based on A/D conversion and the handset software and the gain control based
on the down load data from the PBX are performed. The voice data is sent to IC1 by the serial transmission. The voice
data is transmitted between PBX and DPITS with the protocol originated by KME.
2) Reception signal path
The voice serial data transmitted from PBX is sent to IC1 or IC2 by the serial data. The network control, gain control, A/
D conversion is performed in |C2, then the data is output from the handset speaker. Q31 of the handset speaker
performs the mute operation by controlling IC6.
3) Circuit diagram for transmission/reception signal path
Refer to page 39.
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