V14
VDDE3
3.3V power supply
J18
VDDE4
3.3V power supply
A16
VDDE5
1.8V
~
3.3V power supply
A7
VDDE6
1.8V
~
3.3V power supply
F1
VSSE1
Grounding
V6
VSSE2
Grounding
V13
VSSE3
Grounding
H18
VSSE4
Grounding
A15
VSSE5
Grounding
A6
VSSE6
Grounding
L17
DCDC_PLAY
Power on signal
L18
DCDC_STOP
P_GND
N17
DCDC_LX2
DC- DC in
P17
DCDC_LX1
DC- DC in
T18
DCDC_VUSB
USB voltage input
M17
DCDC_VBAT
Battery power supply
R18
DCDC_VOUT33A
DC/DC 3.3V out
M16
DCDC_VOUT33B
DC/DC 3.3V in
N18
DCDC_VOUT18
DC/DC 1.8V in
P18
DCDC_VSS1
DC/DC grounding
N16
DCDC_VSS2
DC/DC grounding
L16
DCDC_GND
Core grounding
M18
DCDC_CLEAN
Datum circuit grounding
3.5.2 Function introduction to G690
The G690 are microprocessor (
UP) supervisory circuits used to monitor the power supplies in??and
digital systems. They provide excellent circuit reliability and low cost by eliminating external components and
adjustments when used with +5V, +3.3V, +3.0V- powered circuits.
These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines
below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold.
Reset thresholds suitable for operation with a variety of supply voltages are available.
- 48 -
Summary of Contents for X21
Page 1: ...service manual X21 RU ...
Page 42: ...3 L1 1 8V energy storage waveform diagram 4 LCD_CS wabeform 5 LCD_D C waveform diagram 37 ...
Page 43: ...6 LCD_RESET 7 LCD_WR waveform diagram 8 LCD_RD waveform diagram 38 ...
Page 45: ...12 LCD_DB3 waveform diagram 13 LCD_DB4 waveform diagram 14 LCD_DB5 waveform diagram 40 ...
Page 46: ...15 LCD_DB6 waveform diagram 16 LCD_DB7 waveform diagram 17 IREF waveform diagram 41 ...
Page 47: ...18 VCOMH waveform diagram 42 ...
Page 66: ...Chapter Cinque PCB board Circuit diagram Section One PCB board X21 PCB Board 61 ...