CH340G用5V供电时，串口的电压是5V还是3.3V？

VCC = 5V
V3 doesn’t connect to VCC.
VCC = 3.3V
V3 connects to VCC.

High Output Voltage = VCC-0.5 V Minimum
請參照這份 Datashit！
http://cdn2.boxtec.ch/pub/diverse/ch340g-datasheet.pdf

V3
Connects of VCC to input outside power while 3.3V, connects of 0.01uF decoupling capacitance outside while 5V.
一看就知道是菜英文寫的芯片規格書。

  小编厉害

最近一段时间，这个芯片供货好像不足，小编如果用量不大的话，还是得考虑下