Fiche technique: http://jcinfotr.com/Utilitaires/CH340DS1.PDF
Driver http://jcinfotr.com/Utilitaires/CH341SER.EXE
Pinout:
DTR....Data Terminal Ready
RXD....Serial in
TXD....Serial out
VC......3.3V or 5V Supply out selected via switch
CTS.....Clear To Send
GND....0V