您好,设计了一个关于tusb4020bi得电路,1.1V采用的是500mA的LDO芯片,现在现象是usb能识别到,但是不稳定,端口一直在刷新,请问下这个是什么问题?
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
您好,设计了一个关于tusb4020bi得电路,1.1V采用的是500mA的LDO芯片,现在现象是usb能识别到,但是不稳定,端口一直在刷新,请问下这个是什么问题?
下面是回复:
So the hub is recognized by the host, but the hub is always refreshing? Or are the downstream devices connected to the hub refreshing?
Please check that SMBUSz is not pulled low, and that USB_VBUS is steady around 500 mV. Is the clock running continously?
Which power rail is pulling the extra 200 mA when devices are plugged in?
Can you confirm that there is a thermal pad with adequate solder under the hub, inconsistent behavior is often linked to thermal pad issues.
对应中文是
所以主机可以识别集线器,但是集线器总是在刷新?或者下游设备是否连接到集线器?
请检查SMBUSz是没拉低,USB_VBUS是否稳定在500 mV左右。时钟在不停地走吗?
插入设备时,哪个电源轨会额外拉动200 mA?
您能否确认芯片下是否有具有足够焊料的热焊盘,不一致的行为通常与热焊盘问题有关。