Adc Function - Quectel UC15 Hardware Design


Keep the ESD components as closer to the USB connector as possible.

Pay attention to the influence of junction capacitance of ESD component on USB data lines. Typically,
the capacitance value should be less than 2pF such as ESD9L5.0ST5G.

Do not route signal traces under crystals, oscillators, magnetic devices and RF signal traces. It is
important to route the USB differential traces in inner-layer with ground shielding not only upper and
lower layer but also right and left side.
NOTE
UC15 module can only be used as a slave device.
The USB interface is recommended to be reserved for firmware upgrade in your design. The following
figure shows the recommended test points.

3.15. ADC Function

The module provides two analog-to-digital converters (ADC) to digitize the analog signal to 12-bit digital
data. 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.
UC15_Hardware_Design
Figure 35: Test Points of Firmware Upgrade
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