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Carrier Board Design Guide for SOM-9X35 Module
46
I2C2 Bus Level S
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Very fast switching
1V8_VCC_I2C2
1V8_VCC
1V8_VCC
1V8_VCC_I2C2
I2C_SCL_IOEXP2
[17,26]
SCL2
[5,16]
I2C_SDA_IOEXP2
[17,26]
SDA2
[5,16]
R686
0
R193
2K_1%
R191
2K_1%
D61
LRB551V-30T1G/X
30V
0.5A
SOD-323
A
K
Q22
BSS138BKS
60V
320mA
TRANSISTOR DUAL N CHANNEL
S1
1
G1
2
D2
3
S2
4
G2
5
D1
6
C304
0.022uF
16V
X7R
Figure 53: Camera I2C Bus level shift reference circuitry
The front and rear cameras must use independent reset and power down pins. It is recommended to use an
I/O on the expander to control the cameras as there are only 6 GPIOs assigned on the SOM-9X35 module’s
golden finger. Ensure that the I/O on the expander is the same as the cameras' I/O level.
CAM1_PDN
[26]
CAM1_RESET
[26]
R604
15K_1%
R225
18K
R227
15K_1%
R226
18K
CAM_RST
CAM1_PD
3.3V level
3.3V level
1.8V level
1.8V level
Figure 54: Camera control pin level shift reference circuitry
Use a GPIO to control the cameras' power supply to reduce the power consumption if the cameras are turned
on/off by a user. It is recommended to use I/O on the expander to control the cameras' because there are only
6 GPIOs assigned on the SOM-9X35 module’s golden finger.