USB插针的延迟是否危险？

大家好。我将尽可能清楚地解释我的情况。我正在开发一种USB设备，它从USB端口获取电源。端口的5V通过一个限流开关（FPF27 02MX），然后是VDD的电压调节器（MIC5209—3.3YM）。正如你所知道的，开关和调节器在启动时都有一定的延迟。我在交换机数据表中发现，这个延迟大约是10ms，直到它达到期望的VOUT。对于监管机构，我没有找到明确的参考。在我的设计VBUS中，D+和D-直接从USB连接器连接到PIC32 MX695F512H。因此，我的问题是：1。USB插针的延迟是否危险？由于当VDD为0V时，USB信号到达微控制器，因此可能会损坏USB模块或整个芯片。根据数据表：关于任何引脚的电压不是5V宽容，相对于VSS……在VBUS上相对于VSS，电压为-0.3V至（VDD+0.3V）电压。-0.3V到+5.5VI认为我在VBUS上是安全的，但是D+和D-呢？2。如果我的假设是正确的，我需要添加一个USB开关到我的设计，所以我可以关掉信号，直到微控制器开启？我已经找到了几个2频道的开关，所以我可以为我的目的硬接线1频道。我希望你能帮助我在这一个！当做！



      以下为原文

    Hello everyone. I'll try to explain as clear as possible my situation.

I'm developing a USB device that takes its power from the USB port. The 5V of the port pass through a current limit switch (FPF2702MX) and then a voltage regulator (MIC5209-3.3YM) for VDD. As you may know, both switch and regulator have some delay at start-up. I've found in the switch datasheet that this delay is about 10ms until it reaches the desired Vout. For the regulator I haven't found a clear reference. In my design VBUS, D+ and D- are connected directly from the USB connector to the PIC32MX695F512H. So, my questions are:

1. Is the delay dangerous for the USB pins? Since the USB signals reach the microcontroller when VDD is 0V I'm                         affraid they could damage the USB module or the entire chip. According to the datasheet:

Voltage on any pin that is not 5V tolerant, with respect to VSS ................. -0.3V to (VDD + 0.3V)
Voltage on VBUS with respect to VSS ..................................................... -0.3V to +5.5V

I think I'm safe on the VBUS but what about D+ and D-?

2. If my assumption is correct, do I need to add a USB switch to my design so I can turn off the signals until the                         microcontroller is ON? I've found several 2 channel switches so I could hardwire to 1 channel for my purposes.


I hope you can help me on this one!
Regards!