How to design hardware circuit for USB interface?
Posted: 24 Mar 2017, 15:35
The NuMicro® Cortex-M0 family supports powerful full-speed USB devices embedded 1.5kΩ pull-up resistor and LDO 3.3V output.
Please refer to the picture below and note that the impedance of D- and D+ traces should match 45Ω.
Also, 1.5kΩ pull-up resistor and LDO 3.3V output can be controlled by DPPU bit and PWRDN bit of USB_ATTR respectively.
Note: VDD33 is only used by the internal circuit of NuMicro® Cortex-M0 Series and must be connected with 1uF capacitance for voltage stability.
Please refer to the picture below and note that the impedance of D- and D+ traces should match 45Ω.
Also, 1.5kΩ pull-up resistor and LDO 3.3V output can be controlled by DPPU bit and PWRDN bit of USB_ATTR respectively.
Note: VDD33 is only used by the internal circuit of NuMicro® Cortex-M0 Series and must be connected with 1uF capacitance for voltage stability.
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