3.2.12 ON/OFF control circuit
1. ON/OFF control circuit schematic diagram of X21 (RU) is shown in the figure 3.2.12.1:
EN
C62
SFI0402-050E100NP
S2
START/PLAY/PAUSE
L23
601/1005
VCC33
D_GND
P_GND
PLAY/PAUSE
2
START
1
P L A Y / P A U S E
Q2
MMST3906
R12
100K
C14
475/X5R
R19
2M
Q5
MMST3904
Q3
SS8050LT
D4
1N4148WS
R14
47K
R17
100K
R10
100K
R15
470K
R23
1M
D7
1N4148WS
R13
5.6M
D3
1N4148WS
R9
10K
R8
10K
P_GND
P_VDD
OFF
2
P_GND
VCC33
START
3
START
START
R62
100k
C64
SFI0402-050E100NP
PLAY
Figure 3.2.12.1 ON/OFF control circuit schematic diagram
2. Working principle: ON/OFF control is fulfilled through operating ON/OFF button S2 bu users.
When press S2 to power on, S2 is connected, START sends out low level signal, Q2 is saturated on,
battery voltage P_VDD makes EN high level through Q2, R12 and D3 to make power management
module work, power system of the player starts and machine power on; when power off normally (for
instance, press ON/ONN button for a long time or battery electric charge is too low), PNX0101 sends out
OFF high level to make Q3 saturated on to pull EN down to ground, power management module stops
working and machine power off; when accidents happens, system fails, PNX0101 has not any reaction
to any operation, now press S2 and Q2 is saturated on all the time, battery voltage P_VDD charges C14
through Q2, R13 and R19, when C14 is charged higher than 0.5V, Q3 is on, EN is low level and the
player power off. PN knot of R17 and Q5 is the figure is the discharge loop of C14.
3.2.13 MIC circuit
1. MIC circuit schematic diagram is shown in the figure 3.2.13.1:
- 23 -
MIC1
MICROPHONE
R61
2.2K
ADC_VDDA33
ADC_MIC 2
ADC_MIC
C60
106
Q9
MMST3904
R60
470K
C61
104
R59
100K
Figure 3.2.13.1 MIC circuit schematic diagram
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 ...