Hi there!
I'm developing a ignitionmodule for an older type jetski/ universal to older engines.
For this unit I've an huge band of input voltages going from 60-280VAC (and in worstcase more) after a long search on the internet I ended up with the UCC28911-chip and its reverence design.
After implementing the reverence design into my own design, and ordering/soldering the PCB, I cant get the powersupply to work properly..
the output voltage is about 1/2VDC and should be 5VDC.
when I remove the preload resistor, the voltage goes up to 5.2VDC, when I connect an LED to the output, the voltage drops to 2.4VDC and the LED starts blinking softly.
I'v tried changing the IPK resistor, as wel as the VDD resistor.
When hooked up to a scoop, I can see that the voltage on the VDD pin is going up and down between 10 and 5.2V, this wont change if change the inputvoltage (tested with 60VDC and 60-120VAC)
the drain is showing a wierd signal (see blue signal in the picture)
this signal is apearing when the VDD pin is at 10VDC, after this signal, the VDD-pin is slowly dropping to 5.2VDC and starting to go up to 10.2VDC quickly.
the used schematic:
what is wrong with this schematic?
I've used reverence design when designing the PCB.
please help me!
