Panasonic KX-TCD510ALV Service Manual page 72

- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter,
EEPROM, LCD)
- RF Module: IC3
- PLL Oscillator
- Detector
- Compress/Expander
- Amplifier for transmission and reception
- AMP: IC2
- Single OP_AMP for SP
- MIDI (Musical Instrument Digital Interface): IC4
- 16-Tone 32-Poly PCM Sound Generator
- Port (LED direct driver with PWM)
- EEPROM: IC10
- Temporary operating parameters (for RF, etc.)
Refer to EEPROM LAYOUT (HANDSET)
23.2. Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6V: J1)
The Reset signal generates IC1 (78) and 1.8V.
23.3. Charge Circuit
Circuit Operation:
When charging the handset on the Base Unit, the charge current is as follows;
DC+(5.5V ~ 6V) D1
F1 BATTERY+ ... Battery ... BATTERY-
(Base) GND DC-(GND)
In this way, the BBIC on Handset detects the fact that the battery is charged.
The charge current is controlled by switching Q5 of Handset.
Refer to Fig.101 in Power Supply Circuit
23.4. Battery Low/Power Down Detector
Circuit Operation:
"Battery Low" and "Power Down" are detected by BBIC which check the voltage from battery.
The detected voltage is as follows;
- Battery Low
Battery voltage: V(Batt)
().
L1, D1, Q2 (1.8V)
R4, R5 CHARGE+(Base)
R43
().
2.3V ± 50mV
Q3 (2.7V) Q1 (4.0V)
CHARGE+(Handset)
GND CHARGE-(Handset)
72
L4 Q4 D7
CHARGE-