DOWNLOAD Panasonic KX-TG6451CAT / KX-TGA641RUT Service Manual ↓ Size: 3.14 MB | Pages: 94 in PDF or view online for FREE

7

T

E

L Line

D101

Q

111/Q115

RLY

T

ra

n

si

st

o

r

RLY

T

ra

n

si

st

o

r

RLY

T

ra

n

si

st

o

r

RLY

T

ra

n

si

st

o

r

-

+

~

~

-

+

~

~

Hook

 

SW

Hook

_C

T

R

L

Puls

e

Q

112/Q114

Q

131

LSRp

Side

T

one 

Ci

rcu

it

 

TP

1

0

TP

9

MI

C

h

P3_6

P2_1

Fil

te

r

-

+

~

~

-

+

~

~

Ringer

IC

CIDINp

CIDINn

R

ingi

ng

Fil

te

r

D161

IC101

IC301

IC304

IC801

RF PA

3.75V

3.5V

Q

351

1.8V

2.5V

IC303

VDD/AVD

L

D

O_

CT

RL

RF_SUPPLY

4.3V

D138

BAT

Key

 sw

itch 

Ma

tr

ix

 

P5_5-0

P1_5-2

,P2_

0

LED

LED1-4

Q

6

01-Q

604

LC

D

 M

odule

Serial

EEPRO

M

TA

M

 I

C

IC201

X

511

X

tal

(10.368Mhz)

XT

AL1

XT

AL2

IC501

Hands

et

Spea

k

e

r

Mi

c

LCD_CS,LCD_CD,L

CD_RESET

Q6

0

5

-Q6

0

7

SPI_CLK,SPI_DO

CP_

VOUT

1

3.0V

2.5V

SCL2,SDA2

EEP_

W

P

SCL2,SDA2

P5_6

SPI_DI

P5_7

SPI_CLK,SPI_DO

KEY

5-0

RO

W

4

-0

G

P

IO

 3-0

IC561

P4_7-5

BXT

AL

CL

K

CLK(10.2

68M

Hz

)

T

A

M

_

RESE

T

RST

2.5V

1.8V

2.5V

P3_0

PC

M

_

CLK,DI,DO,FSC

PC

M

_

CLK,DI,DO,FSC

PC

M

_

CLK,D

I,DO,FSC

VDDAVD.

VDDIO

VDD

LC

D

 bac

kl

ight

3.5V_PD

3.5V_PD

VCC

SPI2_CLK,DI,DO

,EN

SPI2_CLK,DI,DO

,EN

IC

IC301

3.5V

Q

351

2.5V

IC303

3.5V_PD

IC

IC301

3.5V

Q

351

2.5V

IC303

Q

341

3.5V_PD

PC102

Ringer

DET

Q

331

PO

W

E

R_F

AIL

INT

1

DC

6.5V

Q

162

Q

608

3.2V_PD

3.2V_PD

VDDPA

22

24

29

85

27

26

30

30,20

54,89

19

12,91

42,45,50

10

9

61

82,7

5-71

57-60

,86

45-43

65,6

4

52

63

84

67,6

8

83

56

41

81-78

17-14

RX

o

n

RX

n

RX

p

VDD-PADRV

Tx

on

PSEL

Pon

TX

n

TX

p

BPF

ANT

1

ANT

2

ANT

1

ANT

2

D

A

801

D

A

802

6

5

3

2

95

97

98

93

94

100

92

RFP0

RFP1

RF_RX

n

RF_RX

p

VDD-PADR

RF_T

X

p

RF_T

X

n

RFP4

RFP3

RFP2

RFP0n

VCC

KX-TG6451 BLOCK DIAGRAM (BASE UNIT)

8

Base unit consists of the following ICs as shown in Block Diagram (Base Unit) (P.7).

• DECT BBIC (Base Band IC): IC501

- Handling all the audio, signal and data processing needed in a US DECT base unit
- Controlling the US DECT specific physical layer and radio section (Burst Module Controller section)
- ADPCM code filter for speech encoding and speech decoding (DSP section)
- Echo-cancellation and Echo-suppression (DSP section)
- Any tones (tone, sidetone, ringing tone, etc.) generation (DSP section)
- DTMF receiver (DSP section)
- Clock Generation for RF Module
- ADC, DAC, timer, and power control circuitry
- All interfaces (ex: RF module, EEPROM, LED, Analog Front End, etc.)
- RF Tranceiver (LNA Mixer IF Filter, Modulator/Demodulator, PLL, Vco)

• EEPROM: IC561

- Temporary operating parameters (for RF, etc.)

• FLASH MEMORY: IC541

- Voice Prompt (TAM) D/L Area
- ICM/OGM/MEMO Recording Area

• TAM Companion: IC201

- Voice data compression and decompression
- Speaker Amp

• Additionally,

- Power Supply Circuit (+4.0 V, +3.3 V, +2.5 V, +1.8 V output)
- Crystal Circuit (10.368 MHz)
- Telephone Line Interface Circuit

9

The power is supplied to the BBIC,TAM Companion,Power AMP,LCD module,EEPROM,Flash Memory,LED,LCD backlight from
AC Adaptor(+6.5V) as shown in Fig 1.
When power line failure, the power is supplied to BBIC,TAM companion,EEPROM from telephone line instead of AC Adaptor
through D138 and Q341.

• BBIC (IC501) 

• TAM Companion (IC201) 

AC adaptor 

→ F301 → D301→ IC301 → D353 → IC201 (VDDPA 3.2V)

• RF Power AMP (IC801) 

AC adaptor 

→ F301 → D301→ IC304 → Q608 → IC801 (VCC)

• EEPROM (IC561) 

• Flash memory (IC541)

AC adaptor 

→ F301 → D301→ IC301 → D311 → IC501 (BAT:CP_VOUT1) → IC541 (VDD 3.0V)

• LCD module

AC adaptor 

→ F301 → D301→ IC301 → D311 → IC501 (BAT:CP_VOUT1) → CN1 → LCD module (VDD 3.0V)

• LED

AC adaptor 

→ F301 → D301→ IC301 → D311 → IC501 (BAT:CP_VOUT1) → CN1 → LED (3.0V)

• LCD backlight

AC adaptor 

→ F301 → D301 → IC301→ CN2 → LCD backlight (3.5V)

<Fig.1>

10

• Bell signal detection
• CLIP signal detection
• ON/OFF hook and pulse dial circuit

In standby mode,Q111/Q115 is open to cut the DC Loop current and decrease the ring load.
When ringing voltage appears at the TIP and RING, AC ring voltages transferred as followings;
CLIP signal detection

TIP 

→ C181 → R182 → R185 → IC501(26)(BBIC-CIDINn)

RING 

→ C191 → R192 → R195 → IC501(27)(BBIC-CIDINp)

TIP 

→ C181 → R182 → C184 → R186 → C187 → IC501(30)(BBIC-RINGING)

When power line failure (Because this case is no power to IC501)
TIP 

→ C164 → D161(2) → D161(1) →  IC101(1:5) → R167 → RINGERP

RING 

← D161(3) ← D161(4) ← Q162(c:e) ← IC101(2:8) ← RINGERM

ON hook:
Q111/Q115 is open to cut the DC loop current and voice signal, caused by the following control:
Hook switch (between hook2-4 and hook2-6) is opened and IC501(29)(Hook CTRL) is Low, (and Q114 is open), then Q112 is
OFF,so Q111/115 is OPEN
OFF hook:
Q111/Q115 is ON to make the DC loop current and be possible to transfer voice signal, caused by the following control:
Hook switch (between hook2-4 and hook2-6) make and IC501(29)(Hook CTRL) is High. (and Q114 is open), then Q112 is ON.

The audio signal from Mic (for SP-phone and Corded Handset) is converted from Analog to digital in TAM companion IC(IC201),
then is transfered to BBIC(IC501) through PCM interface.
In BBIC(IC501), these data is converted to Analog, then send out tel line through tel line interface.
On the other hand, the audio signal from tel line is converted from Analog to digital in BBIC(IC501), then is transfered to TAM
companion IC(IC201) through PCM interface.
In TAM companion IC(IC201) ,these data is converted to Analog, then sound out from speaker.
Refer to the fig.2.

<Fig.2>

BBIC(IC501) inclueds the RF transceiver circuit. (LNA,Mixer, IF filter, modulator/Demodulator,PLL, VCO etc).
This RF transceiver is interfaced  with Power-AMP(IC801) and Antenna circuit.

During pulse dialling the hookswitch (Q3, Q4) is used to generate the pulses using the HOOK control signal, which is set high
during pulses. To force the line impedance low during the “pause” intervals between dial pulses, the PULSE_DIAL signal turns
on Q2.