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17

The acoustic signal that entered MIC of SP-Phone is converted into the electrical signal in MIC,and
the signal flows as follows.
→ Analog Amplifier(IC1) → A/D convertor → Digital Gain Amp → Output(IP Line)
MC bias voltage is supplied from IC1 to MIC through R301 and R303

Receiving singnal that enters from IP line flows as follows.
→ Digital Gain Amp → D/A convertor → Analog Amplifier → Output → pin3,4 of IC301(D-class Amplifier)
→ pin5,8 of IC301
After that ,electrical signal is convered to acoustic signal in speaker of SP-Phone.

DG

DG

DG

DG

DG_SP

3.3V

C303

10u 6.3

LED5.0

L303

L304

SG

SG

C316 0.22u
C317 0.22u

C309

1u

10

C304
0.47u
C305
0.47u

R303 1k

R301

1k

R302

2.2k

R329

0

R304

NC

C307 100p

C306

100p

C315

NC

C314

NC

C302 1000p

C301

1000p

C312

1000p

L301

L302

SPK_shutdown

R326 NC

DL301

1

2

3

C308

10u

16

SPH_MICP

SPH_MICN

SPH_SPN

SPH_SPP

C334

100p

50

C344

100p

50

C346

NC

3.3V

D312

2

1

3

D314

D313

D321

D322

IC301

1 STBY

2 NC

3 IN+

4 IN-

5

OUT+

6

VDD

7

GND

8

OUT-

9

FIN

IC1

AD7

MIC1_A_BIAS

AC8

MIC1_AP

AB8

MIC1_AN

AC12

SPK1_AP

AB12

SPK1_AN

AE7

MIC1_B_BIAS

AD8

MIC1_BP

AE8

MIC1_BN

AE12

SPK1_BP

AD12

SPK1_BN

D326

2

1

3

MIC+

MIC-

SP-

SP+

C311

0.01u

C310

0.01u

C252

NC

R390 0

R391 0

R306

10k

R307

10k

MIC

SP

18

IC403 receives the command in I2C interface from IC1 and communicats with EHS equipment,
controls VCOM adjustment and LED ON/OFF. 
Clock for IC403 uses 3.58MHz that is generated in X403,IC405 and IC406.

The communication between the EHS equipment and IC403 is done like the circuit of the above figure.
  Sending:IC403.pin9 

→ R469 → Q452B → Q452C → R465 → R464 → L409 →

  Receiving:

→ L409 → R464 → R465 → R466 → Q451B → Q451C → IC403.pin8

VCOM voltage is a synthetic voltage of VDDN of a minus voltage and six ports of IC403, and it is supplied to the LCD module
and is adjusted in the manufacturing process or in repairing that LCD module needs to be exchanged.

JK603

2

3

1

4

5

L608

L609

L610

AG_S1

8

9

10

EHD_DET

R470

4.7k

R465

22

R468

4.7k(NC)

C452

18p

50

R466 10k

R463

10k

R461

10k

R471

10k

DG

C451

18p

50

DG

R467

10k

R469

4.7k

D451

R464

22

R462

10k

C457

0.1u

16

DG

L408

L409

L410

Q451

Q452

Q453

EHS_DET

EHS_TX/RX

EHS_GND

R401

NC

EHS_DET

EHS_GND

EHS_TX/RX

C469

NC

R410

0

EHS_TX

EHS_DET2

EHS_RX

CN304

3.3V

IC1 pin T3

To IC403 pin8

To IC403 pin9

IC403

EHS

19

Incoming LEDs(Green,Red) are controlled by IC403.

USB circuit supplies the power supply, and is composed of IC401 that detects the overcurrent and IC1 that controls it.
The communication between USB device and IC1 is done directly with DP ,DM of two signal wires. 

IC1 controls SD card using the control signal DAT0 - DAT3,DET,CMD,WP,CLK.

20

The illuminance sensor is a sensor to measure the illuminance under the system requirements of the product andcommunicetes
with CPU in I2C communication.
When the brightness of the LCD backlight is set automatically, the brightness of the LCD backlight is controlled according to this illu-
minance value. 

Main clock for IC1(CPU): 25MHz oscillator circuit

Sub clock for IC1(CPU) : 32.768kHz Oscillator circuit

Main clock for IC5(Co-processor) : 19.2MHz Oscillator circuit