17 CIRCUIT OPERATION (HANDSET)
17.1. Outline
Handset consists ofthe following ICs as shown in
BLOCK DIAGRAM (HANDSET)
(P.48).
•
•
•
•
DECT BBIC (
B
ase
B
and IC): IC1
−
−
−
−
All data signals (forming/analyzing ACK or CMD signal)
−
−
−
−
All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter, EEPROM, LCD)
•
•
•
•
RF Module: CN6
−
−
−
−
PLL Oscillator
−
−
−
−
Detector
−
−
−
−
Compress/Expander
−
−
−
−
Amplifier for transmission and reception
•
•
•
•
EEPROM: IC3
−
−
−
−
Temporary operating parameters (for RF, etc.)
17.2. Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6 V: J1)
→
L1, D1
→
Q2 (1.8 V), Q3 (2.5 V), Q1 (4.0 V)
The Reset signal generates IC1 (53 pin) and 1.8 V.
17.3. Charge Circuit
Circuit Operation:
When charging the handset on the Base Unit, the charge current is as follows;
DC+(5.5V ~ 6V)
→
D1
→
R4, R5
→
(Base)
→
(Handset)
→
L4
→
Q4
→
D7
→
F1
→
...
Battery ... BATTERY-
→
R43
→
GND
→
CHARGE-(Handset)
→
CHARGE-(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 ofHandset.
Refer to Fig.101 in
Power Supply Circuit
(P.46).
17.4. 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;
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•
•
•
Battery Low
Battery voltage: V (Batt)
2.25V ± 50mV
The BBIC detects this level and “
” starts flashing.
•
•
•
•
Power Down
Battery voltage: V (Batt)
2.0V ± 50mV
The BBIC detects this level and power down.
Refer to
Check Point (Handset)
(P.34).
17.5. Speakerphone
The hands-free loudspeaker at SP+ and SP- works as a ringer/alarm as well.
Refer to
Troubleshooting for Speakerphone (Handset)
(P.37).
49
KX-TG1843ALS / KX-TGA122AZS / KX-TGA121AZS
Содержание KX-TG1843ALS
Страница 15: ...6 HOW TO REPLACE THE HANDSET LCD 15 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 20: ...Cross Reference Check Point Base Unit P 25 20 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 22: ...Cross Reference Check Point Handset P 34 22 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 51: ...19 SIGNAL ROUTE 51 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 52: ...52 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 58: ...22 ENGINEERING MODE 22 1 Base Unit 58 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 61: ...22 2 Handset 61 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 65: ...24 CABINET AND ELECTRICAL PARTS BASE UNIT 65 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 67: ...26 CABINET AND ELECTRICAL PARTS CHARGER UNIT 67 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 68: ...27 ACCESSORIES AND PACKING MATERIALS 27 1 KX TG1843ALS 68 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 69: ...27 2 KX TGA121AZS 69 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 71: ...28 3 Charger Unit 71 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 78: ...Memo 78 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...
Страница 83: ...Memo 83 KX TG1843ALS KX TGA122AZS KX TGA121AZS ...