LTE Module Series
EC21 Hardware Design
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3.13. ADC Function
The module provides two analog-to-digital converters (ADC).
AT+QADC=0
command can be used to
read the voltage value on ADC0 pin.
AT+QADC=1
command can be used to read the voltage value on
ADC1 pin. For more details about these AT commands, please refer to
document [2]
.
In order to improve the accuracy of ADC, the trace of ADC should be surrounded by ground.
Table 15: Pin Definition of the ADC
Pin Name
Pin No.
Description
ADC0
45
General purpose analog to digital converter
ADC1
44
General purpose analog to digital converter
The following table describes the characteristic of the ADC function.
Table 16: Characteristic of the ADC
Parameter
Min.
Typ.
Max.
Unit
ADC0 Voltage Range
0.3
VBAT_BB
V
ADC1 Voltage Range
0.3
VBAT_BB
V
ADC Resolution
15
bits
1. ADC input voltage must not exceed VBAT_BB.
2. It is prohibited to supply any voltage to ADC pins when VBAT is removed.
3. It is recommended to use resistor divider circuit for ADC application.
NOTES
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