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8

Oper

ational P

.C

. Board

D101

CHARGE_CONT

A

C

T

+

-

SP

X501

13.824 MHz

ANT

2

ANT

1

TEL

 J

A

CK

L1R

L1T

DCP

DCM

DC J

A

CK

RL

Y

LINE

DETECT

SIDE T

O

NE

CIRCUIT

Q161

Q141

BELL

 

DETECT

HOOK

BELL

Q

111

LIN

LOUT

RF_P

AR

T

HSMIP

HSMIN

IC501

BBIC

INUSE

DETECT

 2

RECEIVE

AMP

DCIN 1 and 3

IC302

VCCP

A

VBA

T_APU

VBA

T

VCC_FE

VCC_IF

VCC_VCO

DCINS

CHARGE_DET

3.0V

DOUBOUT

SCL, SDA

WP

VCC

IC601

FLASH

MEMOR

Y

IC61

1

EEPR

OM

MEMOR

Y

KEYS

R151,R152

Q171

DI,CS

MSG_LED

KEYIN 1~3

KEYS_C~E

SPOUTN

SPOUTP

3.0 V

REGULA

T

O

R

Q351,

 Q352

CLK,DO

STM/CKM

R371

R372

D362

Q701, Q702

CHARGE

DETECT

VCCA

VCC

SCL,RST

CS

,CD,SIO

DCIN 2

CAP

_

SW

CAP_CHG

HS_SUPPL

Y_DET

BA

CKUP

CAP

 CIRCUIT

PO

WER

SUPPL

Y

CIRCUIT

FR

OM

HS

C901

optional

optional

TG6721 only

TG6721 only

ANT2

ANT1

RXp

RXn

RXON

TXp

TXn

TXON

RESET

RSTN

KX-TG681

1/6821 BLOCK DI

A

GRAM 

(BASE UNIT)

LED

T

AM counter P

.CBoard

9

Base Unit consists of the following ICs as shown in Block Diagram (Base Unit) (P.8).

• DECT BBIC (Base Band IC): IC501

- Handling all the audio, signal and data processing needed in a DECT base unit
- Controlling the 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
- PLL Oscillator
- Detector 
- Compress/Expander
- First Mixer
- All interfaces (ex: QSPI FLASH MEMORY, EEPROM, LED, Analog Front End, etc.)
- Integrated 1.9GHz PA for DECT

• EEPROM: IC611

- Temporary operating parameters (for RF, etc.)

• FLASH MEMORY: IC601 (for KX-TG6821 only)

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

• Additionally,

- Power Supply Circuit (+3.0 V output)
- Crystal Circuit (13.824 MHz)
- Charge Circuit

- Telephone Line Interface Circuit

10

DA802

ANT2

ANT1

RXp

RXn

ANT2

ANT1

TXp

TXn

KX-TG6811/6821 BLOCK DIAGRAM (Base Unit_RF Part)

11

(BBIC, Flash Memory, EERROM) is a digital speech/signal processing system that implements all the functions of 
speechcompression, record and playback, and memory management required in a digital telephone answering machine.The
BBIC system is fully controlled by a host processor. The host processor provides activation and control of all that functionsas 
follows.

• Voice Message Recording/Play back

The BBIC system uses a proprietary speech compression technique to record and store voice message in Flash Memory.An
error correction algorithm is used to enable playback of these messages from the Flash Memory.

• DTMF Generator

When the DTMF data from the handset is received, the DTMF signal is output.

• Synthesized Voice (Pre-recorded message)

The BBIC implements synthesized Voice, utilizing the built in speech detector and a Flash Memory, which stored the vocabulary.

• Caller ID demodulation

The BBIC implements monitor and demodulate the FSK/DTMF signals that provide CID information from the Central Office.

• Digital Switching

The voice signal from telephone line is transmitted to the handset or the voice signal from the handset is transmitted to the 
Telephone line, etc. They are determined by the signal path route operation of voice signal.

• Block Interface Circuit

RF part, LED, Key scan, Speaker, Telephone line.

Following information data is stored.

• Voice signal

ex: Pre-recorded Greeting message, Incoming message

Following information data is stored.

• Settings

ex: message numbers, ID code, Flash Time, Tone/Pulse

RF part

ADPCM

Analog
Front
End

&
  
Multi-
plexer

TEL
Line
Interface

Digital
Speech
Processor

Caller ID
Modem

Digital TAM  System

*1

Flash Memory  IC601

*1

 Host CPU

DECT RF system
 TDMA/TDD
 Mod/Demod
 PA/LNA

ADPCM

Keys/ LEDs/ Charge

*1

EEPROM IC611

*1 for KX-TG6821 only

Speaker

*1