User's Manual

UMTS/HSPA Module Series
UC20 User Manual
UC20_Hardware_Design Confidential / Released 49 / 84
1. It is recommended to reserved RC (R=22Ω, C=22pF) circuit on the PCM lines, especially for
PCM_CLK.
2. UC20 works as a master device pertaining to I2C interface.
3.14. ADC Function
The module provides two analog-to-digital converters (ADC) to digitize the analog signal to 15-bit digital
data such as battery voltage, temperature and so on. Using AT command AT+QADC=0 can read the
voltage value on ADC0 pin. Using AT command AT+QADC=1 can read the voltage value on ADC1 pin.
For more details of these AT commands, please refer to document [1].
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
0.2
2.1
V
ADC1 Voltage Range
0.2
4.2
V
ADC Resolution
15
bits
Offset Error
3.5
%
Gain Error
2.5
%
NOTES