Hello, readers welcome to the new post. In this post, we will have a details look at the introduction to CH340. CH340 is a USB bus converted chip and is used as a USB convert to serial interface, USB convert to IrDA infrared or USB convert to printer interface. In serial mode, CH340 offers a common MODEM liaison signal used for enhancing the asynchronous serial interface of a computer. . So let get started.
 Introduction to CH340
The CH340 is a commonly used integrated circuit that is bidirectional USb for conversion of serial converter IC and used for USB signal in UART that can used for communication through miconrollers.
This component is used in different types of Arduino Nano for providing serial-to-USB conversion communication with the board through a USB converter.
CH340 Features
- It is a full-speed USB device interface that comes with USB features type 2.0 and needs crystal and capacitance.
- It is a standard serial interface and is used for upgrading older peripheral devices.
- It is supported by the serial applications program in the computer endpoint Windows operating system
- It is hardware full duplex serial interfacing, supported communication baud rates from 50bps to 2Mbps.
- It is also compatible with MODEM liaison signal DCD, RI, RTS, DTR, DSR, and CTS.
- It also supported the IrDA criterion SIR infrared communication, and also compatible with baud rate varying from 2400bps to
115200bps. - It is also compatible with CH341, using the drive of CH341 directly.
- its working voltages are 5V and 3.3V source voltage.
- It has an SSOP-20 package without lead, compatible with RoHS.
CH340 Pinout and Wiring
| Pin Number | Pin Name | Details |
| 1 | CKO | Clock output |
| 2 | ACT |
Negative phase clock output
|
| 3 | TXD | Serial data output |
| 4 | RXD | Serial data input |
| 5 | V3 |
External 3.3V supply
|
| 6 | UD+ | USB data positive |
| 7 | UD- |
USB data negative
|
| 8 | GND |
IC ground reference
|
| 9 | XI |
External crystal
|
| 10 | XO |
External crystal
|
| 11 | CTS |
Clear to send a signal
|
| 12 | DSR |
Data set ready
|
| 13 | RI | Ring indicator |
| 14 | DCD |
Data carrier detects
|
| 15 | DTR |
Data terminal ready
|
| 16 | RTS |
Request to send pin
|
| 17 | NC | Not connected |
| 18 | R232 | RS232 enable |
| 19 | VCC | Power input |
| 20 | NOS |
Forbid USB device suspending pin
|
Ch340 Equivalent
Ch340C
It is the common replacement for CH340 and supports different types of hardware.
Ch340G
it is like the Ch340C, without osciallotr. So used for replacement in different circuits.
How to install USB serial CH340 driver?
- First of all download windows CH340 Driver.
- Unzip the file.
- Run the installer that is unzipped.
- For Arduino IDE when CH340 is configured there is a COM port in the Tools > Serial Port menu, the COM number for the device can be different based on the system.
What is a USB-to-serial chip?
- The normal standard USB to serial adapter comes with USB processor chips that process USB signals. The USB processors send a processed signal to the serial driver chip that applies accurate voltage and transmits processed data  signals to the serial output
What is the difference between CH340C and CH340?
- The CH340G needed an external crystal oscillator for working and the C340C comes with a built-in crystal oscillator. But both work in the same features and convert USB data from serial UART and vice versa!
Why is CH340 not working?
- Check that Ch340g is connected with power and check through a multimeter. Check that chip type and also the oscillator.
- Check the capacitor between DTR and reset pinout. If it is missed or damaged change it
What is the CH340 driver in Windows 11?
- CH340 is a TTL serial to USB converter. This chip is used in different boards such as Arduino Uno CH340G, ESP8266, etc.
- Boards using C340 chips are not needed to program for accessing processors or to program them. but can be a downside.
What is the voltage of CH340 logic?
- Ch340 chip supported 5 volts and 3.3 volts power supply. For using 5 vol source power, VCC input 5 V power and pin of V3 connected with 4700pF or 0.01uF decoupling capacitance.
Can the serial be converted to USB?
- Older peripheral uses serial plugs and we can use them for USB ports with converting plugs. For the connection monitor, printer, or other devices with serial plugs to computers not have serial ports, use serial to USB converter plug or cord
What is CH340 used for?
- Ch340 is a USB bus conversion chip and uses a USB to UART interface or USB to printer interface. In serial UART mode, Ch340 offers a common MODEM liaison signal used for expanding the UART interface of the computer or upgrading common serial devices to a USB bus.
Does Arduino use CH340?
- Arduino Nano uses FTDI FT232R USB chip, but not CH340. The board that is used is “Arduino Nano” but is not an Arduino Nano, then low-cost Chinese derivative of the Arduino Nano. The CH340 is not used on any official Arduino board
What is CH340G IC?
- Ch340 is a USB bus convert chip and is used for USB conversion to a serial interface. USB convert to IrDA infrared or USB convert to printer interface.
What is the difference between CH340C and CH340G?
- Ch340C comes with in-built crystal and CH340G needs an external crystal input.
What are the properties of USB serial CH340?
- CH340 comes with an integrated USB pull-up resistor, UD+, and UD- pins connected to a USB bus. For serial UART mode, Ch340 comes with data transfer pins, MODEM interface signals, and assistant pins. Data transfer pins are TXD and RXD. RXD keeps high when UART receiving is idle.
CH340G USB to Serial (TTL) Module&Adapter
The CH340G USB to serial TTL adapter is a small USB to TTL serial device, that uses a CH340G chip. It can be used to connect serails devices to a PC through a USB port. its main features are
Read also
- Transistor Symbols | Definition, Terminals & Operating Condition
- Difference between Vacuum Tube and Transistor
- Introduction to C945 Transistor
- Siren Circuit using 2N2907 Transistor
- Difference between Thyristor and Transistor
- Introduction to S9013 transistor
- Introduction to MJE13001 Transistor
