CH340 PDF Datasheet – USB to serial chip

Part Number : CH340

Function : USB to serial chip

Package : SSOP-20 Pin type

Manufactures : ETC

Images :

2 page

Description :

CH340 is a USB bus convert chip and it can realize USB convert to serial interface, USB convert to IrDA infrared or USB convert to printer interface. In serial interface mode, CH340 supplies common MODEM liaison signal, used to enlarge asynchronous serial interface of computer or upgrade the common serial device to USB bus directly. More detail about USB convert to printer interface please referring to the second manual CH340DS2. In infrared mode, add infrared transceiver to CH340 can compose USB infrared adapter, realize SIR infrared communication. Computer or other USB host USB CH340 convert chip UART/RS232/IrDA infrared SIR parallel printer to USB printer 2. Features ● Full speed USB device interface, conforms to USB Specification Version 2.0, only needs crystal and capacitance external. ● Emulate standard serial interface, used to upgrade the former peripheral device, or add excess serial interface through USB. ● Totally compatible with serial application program in computer endpoint Windows operation system. ● Hardware full duplex serial interface, set transceiver buffer, supports communication baud rate varies from 50bps to 2Mbps. ● Supports common MODEM liaison signal RTS, DTR, DCD, RI, DSR and CTS. ● Through adding level converter equipment to supply RS232, RS485, RS422 and other interface. ● Supports IrDA criterion SIR infrared communication, supports baud rate varies from 2400bps to 115200bps. ● For it is through USB converts to serial interface, only compatible with application layer not totally. ● Software compatible with CH341, using drive of CH341 directly. ● Support 5V and 3.3V source voltage. ● Supply SSOP-20 package without lead, compatible with RoHS. The DataSheet of CH340 (the first) 3. Package 2 Package shape Width of plastic Pitch of Pin SSOP-20 5.30mm 209mil 0.65mm 25mil SSOP-20 5.30mm 209mil 0.65mm 25mil Instruction of package Shrink small outline package of 20-pin Shrink small outline package of 20-pin Ordering type CH340T CH340R 4. Pins Pin No. 19 8 5 Pin Name VCC GND V3 9 XI 10 XO 6 UD+ 7 UD20 NOS# 3 TXD 4 RXD 11 CTS# 12 DSR# 13 RI# Pin Type POWER POWER POWER IN OUT USB signal USB signal IN OUT IN IN IN IN Pin Description(description in bracket is only about CH340R) Positive power input port, requires an external 0.1uF power decoupling capacitance Public ground, ground connection for USB connects of VCC to input outside power while 3.3V, connects of 0.01uF decoupling capacitance outside while 5V Input of crystal oscillator, attachment of crystal and crystal oscillator capacitance outside Opposite output of crystal oscillator, attachment of crystal and crystal oscillator capacitance outside Directly connect to D+ data wire of USB bus, set up pull-up resistor internal Directly connect to D- data wire of USB bus Forbid USB device suspending, active with low, set up […]


CH340 Datasheet