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CH340 USB TO TTL
What is USB to TTL converter？
An USB to TTL converter is essentially a connection conversion device, the main function is to provide information interaction of serial port communication, by converting USB to TTL, host computer and serial communication devices can communicate with each other, for example, some industrial sensor devices, automated sensor devices, etc.are involved.
How does USB to TTL work?
By connecting the serial port of module RXD and TXD, the converter chip (such as CH340g) receives data and converts it into a TTL-compatible serial format. This is mainly used for programming the main control chip through a driver program.
What is USB to TTL used for?
USB to TTL converters are commonly used in serial port communication, it mainly used in microcontrollers and embedded development. For example, common microcontrollers or chips such as Arduino,STC,PIC,AVR,STM32，C51，ESP, these are able to communicate via UART by using a TTL to USB for programming.
Types of USB to TTL
Common USB to TTL Serial Cable in the market includes FT232RL,CP2102,CH340,PL2303, the FTDI series is more expensive than other series, it’s more suitable for industrial grade development. The CP2102 comes with its own drivers, the price is higher, is ideal for developing with ESP8266 and high-precision chips. The CH340 is the most cost-effective, easy to use, more suitable for consumer electronics and embedded development. The PL2303 is a legacy product with poor compatibility, more suitable for maintaining older device.
What is CH340？
CH340 is a chip used for USB to TTL conversion, its main function is to use computer’s USB to connect a microcontroller’s uart port, commonly used in scenario such as electronics and embedded system development. The CH340 connects the UART and USB ports to conduct Serial Communication, CH340 is commonly using the CH340g chip, compared to other chips, it offers lower cost, strong performance, high compatibility, high market penetration rate and wide application scenarios, easy to use, supported by numerous detailed tutorials, and suitable for most microcontroller DIY enthusiasts.
Communication frequency is 50bps-2000000bps
Supported baud rate is 2400bps-115200bps
Support windows xp,7,10,1
Crystal frequency is 12MHZ
Power supply is 5V and 3.3V
Compatible with most USB2.0 ports
Drivers support CH341 and CH340, quick setup and use
Only 5V can power external targeted devices, 3.3V is for TTL only
CH340 USB To TTL Schematic
Compared to the CH340g, the CH340c includes a built-in crystal oscillator, omitted the design for a crystal oscillator circuit, more suitable for compact circuit design, the CH340g relatively has been on the market longer, more widely adopted, and offers better compatibility with older circuit design.
Types of CH340
You’re probably looking for a USB TO UART product, considering the price, quality, service and stability, I recommend the CH340 to you!
usb to ttl converter pinout
- +5V pin: Coordinated with the VCC pin, it allows the device’s TTL logic to operate at a +5V level.
- VCC pin
- 3V3 pin: Coordinated with the VCC pin, it allows the device’s TTL logic to operate at a 3.3V level.
- TXD port
- RXD port
- GND port: ground wire pin
If you’re interested in learning about or purchasing the CH340g, please click the link on the right (product page).
If you have any questions about the CH340, don’t hesitate to contact us, we’ll promptly provide you with an answer.
How to install USB To TTL driver for windows?（WCH-CH340）
In general, common driver systems install automatically, but there are many different CH340 detailed models and manufacturers, you may occasionally need to install the driver manually. In this case, you need to download the driver from the manufacturer’s official website to ensure proper functionality.
Our CH340g is manufactured by WCH QinHeng company, their official website provides a download link for the USB to TTL driver (CH340g drive supports 32bit and 64bit windows（xp,7，10，11）,linux,MAC OS ,android）
windows：
After you download the driver, insert the CH340 USB to TTL, you can check its connection status from Device Manager->Ports, the normal situation as the following picture
By using a serial port debugging assistant software, you can transmit data to the chip connected to the TTL port. (Need the bit rate, port name, and other parameters are correctly matched.)
In normal situation, the CH340 indicator light will flash during information interaction, indicating that the device is working properly.
Main performance parameter table
| CH340 USB TO TTL | |
| Chip | CH340g (WCH Nanjing Qinheng) |
| Power Supply Voltage (VCC) | Vmin: -0.5V, Vmax: 6V |
| Current |
Typically: When VCC=5V, current is approximately 0.1mA When VCC=3.3V, current is approximately 0.09mA |
| Operating Temperature Range | Tmin: -40°C, Tmax: 85°C |
| Power | At 5V supply: 75mW (maximum) At 3.3V supply: 33mW (minimum) |
| Overall Dimensions / PCB Dimensions | 52.14mm*16mm / 33mm*16mm |
About CH340 Datasheet
Regarding the design parameters, below is the technical documentation provided by the manufacturer: the CH340 technical manual.
It also provides application strategy reference.
Product Selling Points
Selling point of the product: this module uses the CH340g chip, small size and highly sophisticated, excellent compatibility and outstanding cost performance. The USB port is nickel-plated, it increases plug and unplug cycles, better data transmission performance. Components are covered with heat shrink film, good sealing, to better protect the components, extend their service life, and form an insulating layer, helps prevent short circuits and electrical leakage. The product is packaged in an anti-static and dustproof bag, to better prevent dust and static electricity from affecting the electronics and components.It also includes a PWR-DSP power indicator, TXD and RXD indicator light, able to monitor module operation without testing equipment. You can select the 5V or 3.3V electrical level, connect the jumper cap between 5V and VCC for 5V TTL output, and between 3V3 and VCC for 3.3V TTL output. The module is easy to use, only requires driver installation during the first connection to computer or driver updates, enables the module to operate, it can be used for consumer electronics in non-industrial electronic production, microcontroller or embedded DIY scenario development, wide range of use cases!
The high of CH340
The width of CH340
The back of CH340
FA&Q
How to check CH340 USB to TTL converter?
You can check the status of the CH340 by observing the status at the transmitter and receiver, if there is no microcontroller or other control chip, you can connect the TXD to RXD ports of the USB TO TTL to form a short circuit, and then on other systems like Windows, use a serial port debugging assistant software to send corresponding information, when the sent information and the received information are the same, it indicates functioning properly.
What is difference between CH340 USB To TTL and CP2102 ? who is better？
The CH340 USB to TTL is manufactured by Nanjing Qin Heng company (WCH), while the CP2102 is manufactured by Silicon Labs in the USA. In terms of drivers and compatibility, the CH340 USB To TTL manufactured by WCH requires users to manually install driver when the first connection to a computer or updating drivers, it offers good compatibility. While the CP2102 manufactured by Silicon Labs comes with built-in drivers and provides better compatibility for older versions, in terms of power performance, the CH340 has a higher power, whereas the CP2102 has better power control, more suitable for battery-powered devices during production, however, due to cost constraints, the CP2102 is several times more expensive than the CH340. For learning Arduino and daily lab use, the CH340 USB to TTL is good enough,it’s our top value-for-money option, if you need more professional solution, CP2102 is also a good choice.