WCH, a Chinese integrated circuits manufacturer, has just released a new serial to USB chip called CH340E. Unlike other CH340 chips, it doesn’t require an external crystal and also needs less PCB space and BOM.
CH340 is a 3x3mm tiny chip comes in MSOP10 package and has 10 pins. Although it is smaller than other alternatives, it is a little more expensive than them. But considering other components and PCB size needed, the total cost of the BOM may be lower.
According to Electrodragon, it needs only two external parts to build a full function circuit. They also tested it with up to 150,000 baud rate to flash an ESP8266 chip. Most features and technical specifications are the some for CH340 family including CH340E, so the same drivers will work with it.
- Full-speed USB device interface, compatible with USB V2.0.
- Emulation standard serial port used to upgrade the original serial peripherals or add additional serial port via USB.
- Computer applications under the Windows operating system serial port are fully compatible, without modification.
- Hardware full duplex serial port, built-in send and receive buffer, support communication baud rate 50bps ~ 2Mbps.
- Support common MODEM contact signal RTS, DTR, DCD, RI, DSR, CTS.
- Through the additional level conversion device, providing RS232, RS485, RS422 and other interfaces.
- Software compatible CH341, CH341 driver can be used directly.
- Support 5V supply voltage and 3.3V supply voltage or even 3V supply voltage.
- Built-in clock, no external crystal.
- Available in SOP-16 and SSOP-20 and MSOP-10 lead – free packages, RoHS compliant.
The chip costs about 42 cents with a minimum order of 5 pieces on Eelectrodragon store. There is also an option to get a small board featuring the CH340E for about $1, and maybe cheaper in the future. Finally, the most powerful feature of this chip is that you can easily add USB connectivity to your own design.