The "CH340G" is a USB-to-serial (UART) bridge chip, commonly used to convert USB signals to serial Communication (RS232, RS485, etc.) and vice versa. It is produced by WCH (Nanjing Qin Heng Electronics), a Chinese company specializing in integrated circuit design.
Pinout and Detailed Description:
The CH340G chip has a 20-pin Dual In-line Package (DIP) configuration. Below is the pinout along with the function and detailed explanation of each pin. It is crucial to ensure that every pin is properly connected for optimal functionality.
Pin Function Specifications for CH340G:
Pin Number Pin Name Pin Function Description 1 VCC Power supply input pin (5V or 3.3V depending on the operating voltage). 2 GND Ground (0V), used for return current from all connected circuits. 3 TXD Transmit Data: Serial data output pin (for UART communication). 4 RXD Receive Data: Serial data input pin (for UART communication). 5 DTR Data Terminal Ready: Control signal used to manage flow of data. 6 RTS Request to Send: Control line for data flow control. 7 DSR Data Set Ready: Signal used to indicate readiness for data transfer. 8 CTS Clear to Send: Used to manage data flow, especially for serial communication. 9 V3.3 Output voltage (3.3V) used to power external devices or components. 10 VBUS USB Bus Voltage input (5V), typically used for USB power. 11 USBP USB positive data line, used for serial communication with USB. 12 USBN USB negative data line, used for serial communication with USB. 13 INT Interrupt pin (used for signaling when certain events occur in the system). 14 RST Reset pin: Used to reset the CH340G chip to restart communication or reinitialize settings. 15 SDA Serial Data (I2C Communication) data line. 16 SCL Serial Clock (I2C Communication) clock line. 17 TXD2 Second transmit data (for second UART interface ). 18 RXD2 Second receive data (for second UART interface). 19 DTR2 Data Terminal Ready (second UART interface). 20 RTS2 Request to Send (second UART interface).Pin Function FAQ for CH340G:
1. What is the function of pin 1 (VCC)? Answer: Pin 1 (VCC) is the power supply pin. It provides the necessary operating voltage to the CH340G chip. It should be connected to either 5V or 3.3V depending on the operating system and other components used.
2. Can I use the CH340G with a 3.3V power supply? Answer: Yes, the CH340G can be used with a 3.3V power supply, but you must ensure that all connected components are compatible with 3.3V logic levels.
3. What is the role of pin 3 (TXD)? Answer: Pin 3 (TXD) is the transmit data pin for UART communication. It sends data from the CH340G to the connected serial device.
4. How is the RXD pin (pin 4) used? Answer: Pin 4 (RXD) is the receive data pin, used to receive serial data from a connected device to the CH340G chip.
5. What does the DTR (pin 5) pin do? Answer: The DTR pin is used as a control signal for flow control in serial communication, managing the readiness of the serial data terminal.
6. What is the function of the RTS pin (pin 6)? Answer: The RTS pin (Request to Send) is used in serial communication for flow control. It signals when the sender can transmit data.
7. How does the CTS pin (pin 8) work? Answer: Pin 8 (CTS) is used to signal when the CH340G is ready to receive data, typically used to manage the flow of serial communication.
8. What is the voltage output on pin 9 (V3.3)? Answer: Pin 9 provides a 3.3V output voltage, typically used to power external devices or logic components.
9. What is the function of the USBP (pin 11) and USBN (pin 12)? Answer: Pin 11 (USBP) and Pin 12 (USBN) are the USB differential data lines. USBP carries the positive data signal, and USBN carries the negative data signal for USB communication.
10. Can I use the CH340G to interface with I2C devices? Answer: Yes, you can use the SDA (pin 15) and SCL (pin 16) pins for I2C communication.
11. What does the INT pin (pin 13) do? Answer: Pin 13 is used as an interrupt output pin, signaling when certain events occur in the system.
12. Why do I need the RST pin (pin 14)? Answer: Pin 14 is the reset pin, which is used to reset the CH340G chip. It allows for re-initialization of the chip for reliable communication.
13. How many UART interfaces does the CH340G support? Answer: The CH340G supports two UART interfaces, and the additional TXD2 (pin 17), RXD2 (pin 18), DTR2 (pin 19), and RTS2 (pin 20) pins correspond to the second UART interface.
14. What is the maximum baud rate supported by the CH340G? Answer: The CH340G supports a maximum baud rate of up to 2 Mbps, making it suitable for various serial communication needs.
15. What are the power supply requirements for the CH340G? Answer: The CH340G requires a 5V power supply (or 3.3V for low-power applications), and it should not exceed the voltage range of 3.3V to 5.5V for optimal performance.
16. Can the CH340G be used to connect USB peripherals to microcontrollers? Answer: Yes, the CH340G is frequently used to interface USB peripherals to microcontrollers, enabling serial communication between USB devices and microcontroller-based systems.
17. Is the CH340G compatible with both Windows and Linux? Answer: Yes, the CH340G is compatible with Windows, Linux, and macOS. You may need to install specific drivers for your operating system.
18. What should I do if my CH340G is not recognized by my computer? Answer: Ensure the correct drivers are installed for your operating system. You may also need to check the USB connection and ensure the VCC and GND pins are correctly connected.
19. Can the CH340G be used with Arduino boards? Answer: Yes, the CH340G is commonly used as a USB-to-serial interface for Arduino boards that lack native USB support, such as the Arduino Uno.
20. How do I reset the CH340G chip? Answer: To reset the CH340G, you can momentarily pull the RST pin (pin 14) low, which will restart the chip and reinitialize the USB connection.
This detailed explanation should help clarify the function of every pin on the CH340G and answer common questions regarding its use. Let me know if you need further details!
