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Copying is strictly prohibited 

9

 

 
Fig. 2-3 shows the generated power voltages of this unit. 
The eight different power voltages are generated in the ICD-MS1 as described below. 
 
c UNREG 2.5 [V] voltage 

→ IC522, L521, Q522, IC561, L561 

•  This is the voltage that is supplied from AC adapter and battery, and becomes VDD voltage when driving IC168 (POWER AMP). 

•  This voltage becomes the power source for the power voltages that are described in the following items 2 and 3. 

 
d VCC 3.5 [V] voltage

→ +3.5[V] generated by IC522, L521 and Q522. 

•  This voltage becomes the power source for the power voltages that are described in the following items 4 and 5. 

e VCC 4.0 [V] voltage 

→ +4.0[V] generated by IC561 and L561. 

•  This voltage becomes the power source for the power voltages that are described in the following items 6 to 8. 

 
f SYS_VCC 3.3 [V] voltage 

→ IC524 

•  This is the +3.3 [V] power voltage for driving the system controller IC722, timer (REAL TIME CLOCK) and others. 

•  This power voltage drives the LCD together with the +3.0 [V] power voltage after it has passed through IC728. 

 
g MS_VCC 3.3 [V] voltage 

→ IC523 

•  This is the power voltage that is supplied to the Memory Stick, and is +3.3 [V]. 

 
h PCM_VCC 3.3 [V] 

→ IC562 

•  This is the power voltage that drives ADPCM IC164, and is +3.3 [V]. 

 
i MIC_VCC 3.3 [V] voltage 

→ IC563 

•  This is the power voltage that is used in microphone amplifier IC161, AGC IC162, and the VOR detection circuit. This is the +3.3 [V] power voltage. 

 
j DIVID_VCC 3.5 [V] voltage 

→ IC564 

•  This is the power voltage that is used in DIVIDER IC165, and is +3.5 [V]. 

Copying is strictly prohibited 

 

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Fig. 2-3    Generated power voltages   

 
DC-DC 
CONVERTER 

 
POWER 
CONTROL 
 

+3.3 [V]     

    REG 

+3.3 [V]     

    REG 

+3.5 [V]     

    REG 

+3.3 [V]     

    REG 

+3.3 [V]     
REG 

UM-4×2 

D1 

 IC561 

IC562 

IC563 

IC564 

IC523 

Q522 / IC522 

UN REG 2.5[V]

 

 VCC 4.0

[V]

 

VCC 3.5

[V]

 

PCM_VCC 3.3[V]

 

MIC_VCC 3.3[V]

 

DIVID_VCC 3.5[V]

 

SYS_VCC 3.3[V]

 

MS_VCC 3.3[V]

 

  DC IN 3.0V 

IC168  POWER AMP 

IC164   ADPCM 

IC165  DIVIDER 

IC161  AGC  
IC162  MIC AMP 
IC163  VOR DETECTOR 

IC721  REAL TIME CLOCK 
IC722  SYSTEM CONTROLLER 
IC723  EEP ROM 
IC727  S-RAM 

MEMORY STICK   

 

+3.0 [V]     

    REG 

J1 

LCD720 LCD UNIT ( VCC / VC1 )

 

IC728 

e 

IC524 

c 

d 

h 

i 

j 

f 

g 

Copying is strictly prohibited 

11

 

 
The basic operation of the power supply circuit of this unit remains the same in both when it is operated on an alkaline battery and when it is operated on an AC adapter. 
Because this unit does not have the POWER switch, the system controller IC722 controls supply of the power to each block in accordance with the modes that are called as the 
sleep mode and wakeup mode, and in accordance with the operating statuses such as recording and playback for lower power consumption. How the respective power 
supplies are controlled and operated, are described as follows. Refer to Section 2-1. "Discriminating Power Supplies" for the differences due to connection of the different power 
supplies to this unit. 
 
‹

 
1.   First, the UNREG 2.5 [V] is supplied to the unit from either the battery or AC adapter. This voltage is used as the power voltage for the POWER AMP IC168, but the system 

controller IC722 controls operation of IC168 in accordance with the operating status of the unit. 

 
2.   The UNREG 2.5 [V] passes through the over-discharge protection circuit consisting of IC521 and Q521, and is input to pin-3 [CE] of the POWER CONTROL IC522 and 

pin-3 [CE] of the +3.3 [V] REG IC524 as the selection voltage (chip enable signal). 

 
3.   When the POWER CONTROL IC522 enters the active operating state as it receives the CE signal, it outputs the PWM signal of about 100 kHz from pin-5 [EXT] to drive 

Q522, and outputs the VCC 3.5 [V] at the cathode of the diode D521. The VCC 3.5 [V] is then input to pin-2 [VIN] of the +3.3 [V] REG IC524. At this time, duty cycle of the 
PWM signal output from pin-5 [EXT] is varied by the input voltage so that the stable PWM output signal can be obtained. 

 
4.  As the +3.3 [V] REG IC524 receives the VCC 3.5 [V], it outputs the SYS_VCC 3.3 [V] from pin-5 [VOUT] and supplies the power to the system controller IC722, timer IC721, 

EEP ROM IC723 and S-RAM IC727. The +3.3 [V] power is also supplied to the LCD block LCD720 but the system controller IC722 controls the LCD display operation in 
accordance with the operating status of the unit. 

 

5

3

2

1

5

2

3

3

1

1

121

UN REG 2.5[V]

L521

D521

VCC 3.5[V]

Q522

IC521,Q521

TO IC168 POWER AMP.

 

EXT

VDD

VOOT

CE

IC522
POWER CONTROL

IC524 +3.3[V]REG

SYS_VCC 3.3[V]

CE

VIN

VOUT

IC726
RESET

IC721
TIMER

VIN

VOOT

D721

XRST

TO
IC723 EEPROM
IC727 S-RAM
LCD720

IC722
SYSTEM
CONTROLLER

VCC

OUT

Over-discharge
protection circuit

 

Fig 2-4 Supplying power to the system controller and timer (RTC) 

Copying is strictly prohibited 

12

 

‹

 
1.   When a Memory Stick is inserted in the insertion slot, the Memory Stick detection switch S7 is turned on and pin-151 [MSEJ] of the system controller IC722 goes "L". 
 
2.   Due to the internal structure of the Memory Stick, pin-6 of the connector CN723 of the Memory Stick insertion slot is connected to ground and pin-9 [MSINS] of the system 

controller IC722 goes "L". 

 
3.   As the result of the operations as described above in items 1 and 2, the system controller IC722 recognizes that the Memory Stick is inserted and outputs the "H" signal from 

pin-42 [MS POW]. 

 
4.   The "H" output signal from pin-42 [MS POW] of the system controller IC722 is input to pin-3 [CE] of the +3.3 [V] REG IC523 so that the MS_VCC 3.3 [V] is supplied from 

pin-5 [V OUT] of IC523 to the Memory Stick. At the same time, the message "MEMORY STICK ACCESS" appears on the LCD. 

 
5.  When the Memory Stick is ejected, the detection switch S7 of the Memory Stick is turned off and pin-6 of CN723 is opened. As the result pin-151 [MSEJ] and pin-9 [MS INS] 

of the system controller IC722 go "H" and pin-42 [MS POW] of the system controller IC722 goes "L". Therefore pin-3 [CE] of the +3.3 [V] REG IC153 also goes "L". When 
the power supply to the Memory Stick is stopped, the message "NO MEMORY STICK" appears on the LCD display at the same time. (However, when this unit is in the hold 
mode, "HOLD" appears on the LCD display.) 

 

5

2

3

9

42

151

When a Memory Stick 
is inserted, pin-6 is 
connected to ground.

6

S7

CN1-5Pin

(MS  Inserted: L  Not inserted: H)

(MS  Inserted: L  Not inserted: H)

(MS  Inserted: L  Not inserted: H)

MS-EJ

CN723

9

3

1

10

CE

VOUT VIN

IC523
+3.3V REG

MS_VCC 3.5[V]

MEMORY
STICK

R763

R704

MS INS

SYS_VCC 3.3[V]

MS POW

MS EJ

IC 722
SYSTEM  CONTROLLER

R742

B+

 

 

Fig. 2-5 Detection of memory stick and supplying the power