KX-TG2560B, KX-TG2560S - Panasonic Telephone Service Manual (repair manual). Page 58

58

C208

Q204

R202

R239

D204

R217

50

+

C

D203

Q203

R206

R207

R901

R911

IC201

R205

44

45

35

R910

34

37

C205

C204

C218

C219

Power
Down

Reset
30 ms

Batt
Low

63  POWER DOWN

8  RESET

IC901

34  CHARGE

62  BATT LOW

35  ID CODE

When the battery is installed in the handset, the reset circuit consisting of R207, C208, and inside IC201 functions, inputting a
reset signal to the CPU. This ensures that the unit will operate normally without the user's needing to switch the power off and on.
When the voltage from the batteries drops to 3.5 V, 3.5 V voltage detector inside IC201 operates and inputs a battery low signal
to the CPU. This causes the Recharge LED to turn on. If voltage continues to drop and reaches 3.2 V, 3.2 V voltage detector
inside IC201 operates and outputs a power down signal to the CPU. This causes power to be cut off automatically and prevents
the battery from over discharging. Q203 is a charge detector that informs the CPU whether or not the handset is currently being
charged.
During charging, ID data is sent from the base unit. Q204 receives this ID data and sends it to the CPU.

After setting headset into headset jack (CN201), pin 3 of CN201 becomes OPEN and Q206 becomes OFF, input of 9 pin of
IC201becomes L 

→

 H. Therefore switch inside IC201 changes, a signal that input from headset mic to pin 25 of IC201 passes

through mic amp of IC201, is inputted to modulator of RF Circuit as signal from handset mic.
On the other hand, received audio signal is outputted from headset speaker. At this time, pin 4 of CN201 becomes OPEN,
speaker route of handset is cut off, and Amp of IC201 changes to output gain setting for headset.