CH340区别
CH340G USB转串⼝，推出时间最早，需外挂晶振，应⽤最⼴SOP16
CH340C USB转串⼝，内置晶振，引脚兼容CH340G SOP16
CH340E USB转串⼝，内置晶振，超⼩封装MSOP10
CH340B USB转串⼝，内置晶振和EEPROM，引脚兼容CH340G SOP16
CH340T USB转串⼝ SSOP20
CH341T USB转串⼝、IIC SSOP20
CH341H USB转SPI SSOP20
CH341A USB转串⼝、并⼝、IIC和SPI SOP28