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

• DTMF Generator

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

• 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, Key scan, Telephone line.

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

 Host CPU

TDD & TDMA
 with FHSS
Processor

ADPCM

Keys/Charge

EEPROM IC611

10

The power supply voltage from AC adaptor is converted to VBAT (3.0V) in IC302. And +3.0V for peripherals and analog part is
insulated from VBAT by Doubler of BBIC.
Circuit Operation:

6.5V

VBAT

RSTN(Reset) 

pin 54

VBAT

pin 10

pin 57

pin 9

pin 15

IC501

IC301

IC611

BBIC

DOUBLER OUT
For peripherals

VDDC (1.2V)

AC Adaptor

3.0V

DC/DC

CONVERTOR

EEPROM

IC611

Receive

Amp.

+3.0V

STM/CKM

RF Part

Startmonitor

(IC501 57pin)

VDDC (1.2 V)

VBAT

Reset (RSTN) 
(IC501_54 pin)

BBIC chip initialize

(CKM/STM)

11

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

D361

R372

D362

R371

CHARGE+

F301

DCP

+6.5V

+

CHARGE-

(     )

C306

DCM

K            A

12

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

In the idle mode, Q141 is open to cut the DC loop current and decrease the ring load. When ring voltage appears at the Tip (T)
and Ring (R) leads (When the telephone rings), the AC ring voltage is transferred as follows:
T 

→ L101 → R111 → C111 → Q111 → BBIC pin 5 [BELL]

When the CPU (BBIC) detects a ring signal, Q141 turns on, thus providing an off-hook condition (active DC current flow through
the circuit). Following signal flow is the DC current flow.
T 

→ L101 → D101 → Q141 → Q161 → R163 → R167 → D101 → L102 → P101 → R

Q141 is open, Q141 is connected as to cut the DC loop current and to cut the voice signal. The unit is consequently in an on-
hook condition.

Pin 6 of BBIC turns Q141 ON/OFF to make the pulse dialing.

Basically this circuit prevents the TX signal from feeding back to RX signal. As for this unit, TX signal feed back from Q161 is
canceled by the canceller circuit of BBIC.

3.0V

RX

Pin 16 of IC501

R176

R175

R178

C178

C175

Q171

R172

R171

Hook

Pin 6 of IC501

Pin 28 of IC501

59 pin of IC501

TX

BELL

C173

R165

C167

R163

R167

C142

D143

C168

C181

R145

R164

Q161

C163

R161

Q142

Q141

R142

R141

R181

C184

C101

C102

D101

P101

SA101

L1T

L1R

TEL  JACK

3.0V

R114

R111

C111

C113

D113

C112

R112

R113

Q111

3

4

2

1

C176

C165

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