UP-X200 (serv.man10). Parts Guide - Sharp EPOS Parts Guide (repair manual). Page 11

UP-X200

System Block Diagram

– 9 –

The UP-X200 is furnished with 4 switching power supply circuits for system use.

•  5V step up voltage circuit for liquid crystal display power supply, USB power supply (synchronous rectification system, switching frequency 1MHz,

automatic PWM-PFM switching)

•  3.3V step down voltage circuit for system use (synchronous rectification system, switching frequency 1MHz, automatic PWM-PFM switching)   

•  3.3V step down voltage circuit for CF/SD card use (synchronous rectification system, switching frequency 1MHz, automatic PWM-PFM switching)   

•  1.3V step down voltage circuit for CPU core use (synchronous rectification system, switching frequency 1MHz, automatic PWM-PFM switching)

Because the battery used by the UP-X200 is a lithium ion 1 cell type, the maximum battery voltage is 4.2V.
Therefore the 5V power supply uses a step up voltage circuit.
The 5V and 1.3V power supplies are controlled by SA_PWR_EN. Operation and output of these power supplies are stopped while the main unit is
OFF. (However, because of the 5V power supply is output from the diode in the IC, approximately 3-4V is output.)
The power supply for cards is controlled by CARD_VCC_ON.
The input side power supply of the 3.3V supply for system use normally runs to a certain extent. Although there is a switch on the output side, this is
controlled so that it is always off when the main unit is off to ensure that no voltage is output to the power supply circuit when the auxiliary battery is
backed up in cases where there is no main battery. This means that the system power supply is approximately 3.1V in the OFF status.
Output from the power supply circuit for system use is supplied to the system either directly or via the regulator.
Except during voltage measurement, the power supply circuit for the auxiliary battery for system backup is normally charging and operating at step up
voltage.
Output uses a 3.3V step up voltage circuit and the charge pump method. Charging uses the CV method with a regulator.

 

 

Auxiliary 
battery

Auxiliary 
battery

 

 

AUD_PWR_ON

(CF G/A) 

LCDC circuit 
power supply

LCDC circuit 
power supply

LCDC circuit 
power supply

Audio circuit 
power supply

Audio circuit 
power supply

SD CARD 

CF CARD 

CARD_VCC_ON 

(CF G/A) 

SA_PWR_EN

(CPU) 

From charging 
circuit

1.3V 

3.3V 

5V 

5V step up 
power supply

 

3.3V step down 
power supply

 

 

 

3.3V 

2.0V 

3.3V 

2.5V 

1.5V 

RTC 

3.3V 

1.3V step down 
power supply

3.3V step down 
power supply

3.3V step up
power supply

Power Supply Name

Switch

(Regulator)

Output

Voltage

Control Signal

OFF

Application

VCC5

IC1201

5V

SA_PWR_EN

3 - 4V

USB/LCD power supply

VCC3

Q1205

3.3V

SA_PWR_EN

3.1V

3.3V power supply for system

CARD_VCC

IC1204

3.3V

CARD_VCC_ON

Dependent on setting

3.3V power supply source for CF/SD cards

VCC_CORE

IC1203

1.3V

SA_PWR_EN

0V

1.3V power supply for CPU core

CF_VCC

Q1301

3.3V

#CVCC3EN

Dependent on setting

3.3V power supply for CF card

SD_VCC

Q1302

3.3V

SD_PWR_ON

Dependent on setting

3.3V power supply for SD card

VCC_AUD1V8

IC1305

2V

AUD_PWR_ON

0V

Power supply for CODEC core

VCC_AUD3V

(none)

3.3V

3.1V

Digital power supply for CODEC

VCC_AMP

IC1302

3.3V

AUD_PWR_ON

0V

Analogue power supply for CODEC

TC6393_2R5V

IC1304

2.5V

SA_PWR_EN

0V

VRAM power supply for LCDC

TC6393_1R5V

IC1307

1.5V

SA_PWR_EN

0V

Core power supply for LCDC