Product Info

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design
3-51
/ 105
3.13. ADC Interfaces
The module provides two analog-to-digital converter (ADC) interfaces. 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 16: Pin Definition of ADC Interfaces
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 ADC function.
Table 17: Characteristic of 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 a resistor divider circuit for ADC application.
3.14. Network Status Indication
The network indication pins can be used to drive network status indication LEDs. The module provides
two pins which are NET_MODE and NET_STATUS. The following tables describe the pin definition and
logic level changes in different network status.
NOTES