UMTS/HSDPA Module
UC15 Hardware Design
UC15_Hardware_Design Confidential / Released 46 / 72
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It is important to route the USB signal traces as differential pairs with total grounding. The impedance
of USB differential trace is 90ohm.
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Pay attention to the influence of junction capacitance of ESD component on USB data lines. Typically,
the capacitance value should be less than 2pF.
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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.
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Keep the ESD components as closer to the USB connector as possible.
UC15 module only can be used as a slave device.
3.12.1. Firmware upgrade
The USB can be used to upgrade firmware. The PWRKEY pin must be pulled down before the firmware
upgrade. Please refer to the following figure for firmware upgrade.
Figure 28: Connection of firmware upgrade
3.13. ADC Function
The module provides two analog-to-digital converters (ADC) to digitize the analog signal to 12-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].
NOTE
