DOWNLOAD Panasonic KX-TG2511RUM / KX-TG2511RUN / KX-TG2511RUS / KX-TG2511RUT / KX-TG2512RUN / KX-TG2512RUS / KX-TG2521RUT / KX-TGA250RUM / KX-TGA250RUN / KX-TGA250RUS / KX-TGA250RUT Service Manual ↓ Size: 3.56 MB | Pages: 83 in PDF or view online for FREE

13

The voltage from the AC adaptor is supplied to the charge circuits.

The caller ID is a chargeable ID which the user of a telephone circuit obtains by entering a contract with the telephone company
to utilize a caller ID service. For this reason, the operation of this circuit assumes that a caller ID service contract has been
entered for the circuit being used. 
The Caller-ID data from exchange is supplied to the telephone using either method of FSK or DTMF. The method is chosen
according to the exchange of telephone office. This unit is available to receive the data with both methods and displays the
received data on LCD.

• FSK (Frequency Shift Keying) format

• DTMF format

It is the method to send the telephone number of calling party with DTMF to the telephone. DTMF is sent before the first bell sig-
nal.
The data is sent in turn; first the start code, secondly the telephone number of calling party, lastly end code.
The DTMF is chosen from A (1633 Hz and 697 Hz), B (1633 Hz and 770 Hz), C (1633 Hz and 852 Hz) and D (1633 Hz and 941
Hz) as the start code and end code according to the exchange.

D362

R37

2

R371

CHARGE+

F301

DCP

CHARGE-

+6.5V

DCM

STD Ring / 20Hz
Tip-Ring

FSK

DATA in

1st Ring

Silent interval

2nd Ring

DATA

0.1Vrms

70Vrms

1300Hz or
1200Hz
=DATA "1"

2100Hz or
2200Hz
=DATA "0"

Startcode

Endcode

Calling party's 
telephone number

DTMF

1st Ring

0.1Vrms

70Vrms

14

SPEAKER

RECEIVER

MIC

CHARGE

CIRCUIT

Q4, Q6

Q9, R8Q

9

, R

8

CHARGE(+)

CHARGE_C

TRL

CHARGE_DE

T

EEP

R

OM

SCL

SD

A

R45

VB

A

T

BA

T

T

-

1.8

 V

Q2

1.8

 V

CP 3.0

 V

LC

D

CD

RESE

T

CSB

SD

A

 SCL

CPU

Analog

F

ront

End

D/A

A/D

37

35

25

24

21

20

34

33

63

64

 42

27

48

49

69

60

61

72

ADPCM

C

odec

Filt

er

DSP

Speech

Dec

oding

Speech

Enc

oding

BMC

Burst

Dec

oding

ANT1

Burst

Enc

oding

RF 

PLL

MOD/DEMOD

2

3

87

86

RXn

ANT1

RXp

TX

p

TX

n

9

10

XT

A

L

X1

10.368

MH

z

BA

T

T

E

R

Y

50

ON SWIT

CH

KEY

P

AD

Char

ge

Pu

m

p

RO

W

S

C

O

LUMNS

CP3V

CP3.0V

CP_LED

54, 55, 56, 57

14, 15, 16, 17, 52

BBIC

 62

LDO_C

TRL

CP3V

71

CHARGE

C

ONT

A

C

T

S

BA

T

TER

Y

T

ERMINAL

KX

-T

GA251 BL

OCK DIA

GRAM (Handset)

BA

T

T

ER

Y_ON

15

Handset consists of the following ICs as shown in Block Diagram (Handset)

• DECT BBIC (Base Band IC): IC5

- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter, EEPROM, LCD, RF Power Amp.)
- PLL Oscillator
- Detector
- Compress/Expander
- Reception
- Integrated 1.9 GHz PA for DECT

• EEPROM: IC3

- Temporary operating parameters (for RF, etc.)

When power on the Handset, the voltage is as follows;

BATTERY(2.2 V ~ 2.6 V: BATT+) → F1 → Q2 (1.8 V), IC5-48pin (3.0V)
The Reset signal generates IC5 (67 pin) and 1.8 V.

When charging the handset on the Base Unit, the charge current is as follows;

DC+(5.5 V) → R371 → R372 → D362 → CHARGE+(Base) → CHARGE+(Handset) → Q4 → F1 → 
BATTERY + Battery...

BATTERY- → R45 → 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 Q9 of Handset.
Refer to Fig.101 in Power Supply Circuit

“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)   2.25 V ± 50 mV

The BBIC detects this level and "

" starts flashing.

• Power Down

Battery voltage: V(Batt)   2.0 V ± 50 mV
The BBIC detects this level and power down.

The hands-free loudspeaker at SP+ and SP- is used to generate the ring alarm.

1.8 V

Reset
(IC5_67pin)

Battery +

16

The power supply is as shown.

R1

TP2

TP1

J1

AC Adaptor

F1