CH340 programmer

 3D preview, actual product for verification!

The module is about the same size as the modules sold on Taobao. This module uses an ordinary male USB port and can be directly plugged into the computer. It also has a Micor USB female socket that can be extended with a data cable to facilitate programming operations.

CH340 chip supports 5V power supply voltage or 3.3V power supply voltage. When using a 5V working voltage, the VCC pin of the CH340 chip inputs an external 5V power supply, and the V3 pin should be connected to an external power supply decoupling capacitor with a capacity of 0.1uF. When using 3.3V working voltage, the V3 pin of the CH340 chip should be connected to the VCC pin, and an external 3.3V power supply should be input at the same time, and the working voltage of other circuits connected to the CH340 chip should not exceed 3.3V.

If you use CH340C, you don't need to solder the crystal oscillator circuit part, because it has its own crystal oscillator inside!

Also, use tantalum capacitors at the output of 1117-3.3, which will make the LDO output more stable. For a detailed introduction, please go to Station B to watch the evaluation of 1117-3.3LDO by Mr. Sun from the Engineering Department. Click to watch the evaluation video! ! !

Another point is that the crystal oscillator should be as close to the chip as possible. The wiring should be as thick as possible and should be grounded. It is best to have π-shaped wiring. This is what I summarized after watching the video. I don’t know if the teaching in the video is correct! ! Finally, I hope it is helpful to you. If there are any mistakes, please correct me! ! Thanks! !