FT8430 smart Chinese high input voltage buck converter with just 3-pins
Published: 30 October 2021
Last updated: 05 January 2023
When reverse engineering the electronics of a Wattmeter from AliExpress, I came across a remarkable Chinese switching DC-DC converter chip that I had never seen before: the FT8430. I want to bring this to your attention here.
- Only 3 pins
- Maximum input voltage 300V
- Switching frequency 50kHz
The manufacturer is Fremont Micro Devices (FMD). Apparently they don't need the west because their website is only in Chinese.
The maximum input voltage is with 300V much higher than comparable chips from the west, so you can supply directly a from the rectified mains voltage:
No electrical connection to the GND
This design is remarkably clever because the IC can only indirectly measure the output voltage.
How does this work?
This shows that the days of the Chinese copying everything are over.
The FT8430 is not for sale in the west
Why isn’t the FT8430 for sale at Mouser or Digikey?