Adc Function - Quectel EC21 Series Hardware Design

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.
ADC0 45
ADC1 44
The following table describes the characteristic of the ADC function.
Table 16: Characteristic of the ADC
Parameter
ADC0 Voltage Range
ADC1 Voltage Range
ADC Resolution
NOTES
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.
EC21_Hardware_Design
Description
General purpose analog to digital converter
General purpose analog to digital converter
Min. Typ.
0.3
0.3
Confidential / Released
LTE Module Series
EC21 Hardware Design
Max. Unit
VBAT_BB V
VBAT_BB V
15 bits
48 / 94