Analog Circuit - Panasonic KX-T7633 Service Manual

10.8. OPTION DETECTION
When the option is connected with CN3 and CN10, IC3 detects the option connection by the
following voltages.
- IC3-pin 63 : 3.3V
- IC3-pin 63 : 2.1V
- IC3-pin 63 : 1.7V
- IC3-pin 63 : 1.3V

10.9. ANALOG CIRCUIT

This circuit performs the setting of the call path/vol. adjustment in each call mode by DSP built in
IC5.
The audio gain of each call is determined by download data from PBX.
- IC5 sends each audio data to IC4 by PCM interface.
- IC5 receives each audio data from IC4 by PCM interface.
1. Handset Call
Transmitting signal is inputted from handset microphone and
amplified by IC4 built-in Amp
PCM data
Transmitting signal inputted from handset microphone is
controlled by transmission switching SW IC7 as below.
IC3-pin 52 L : Handset Call
(IC3-pin 52 H : Headset Call)
No option connection with CN3 and CN10
Option connection with CN3 only
Option connection with CN10 only
Option connection with CN3 and CN10
Gain adjustment by DSP of IC5
A/D conversion
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inputted to IC5 in
then sent to PBX.