Doc. No: Unex-QSG-21-001
19/27
A printed version of this document is an uncontrolled copy
© 2021 Unex Technology Corporation – Company Confidential
If a SOM-301 is added to the mPCIe port, it is possible to tie the tamper signal of SOM-301
and OBU-301(v2)/OBU-351 together. In this case, it can be selected with the DIP switch
SW2.2. For more information, please see
for details.
8.1.2.4.
SAR ADC
Figure 15: SAR ADC input (J4)
Table 12: SAR ADC functions
Pin
Symbol
I/O
Level (V)
Description
J4.1
SAR_ADC_CH0
I
3.3
SAR ADC input. /sys/bus/iio/devices/iio\:device0
J4.2
SAR_ADC_CH1
I
3.3
SAR ADC input. /sys/bus/iio/devices/iio\:device1
J4.3
SAR_ADC_CH2
I
3.3
SAR ADC input. /sys/bus/iio/devices/iio\:device2
J4.4
SAR_ADC_CH3
I
3.3
SAR ADC input. /sys/bus/iio/devices/iio\:device3
J4.5
GND
G
-
Ground
Table 13: SAR ADC performance
Resolution
ENOB
(Effective number of bits)
Sampling Frequency
10 bits
(0-1023, 3.22mV/step)
9 bits
2.5 MHz
J4 consists of 1.5mm pitch PTHs (Plated Through Holes) reserved for SAR ADC
(Successive-Approximation-Register Analog-to-Digital Converter) function. For connecting
the ADC signal, ADC signal wires can be soldered directly into PTHs. (Wires with JST 5P-
SZN 1.5mm pitch board-in connector can be handled more easily when soldering.)
SAR ADC
J4
1
2
3
4
5
