Hello everyone,
we are currently trying to bring up the L6591 without PFC, but unfortunately we have not been successful so far.
It looks like the L6591 is not able to start up correctly.
The Vcc voltage slowly rises to about 14V with the built-in HV startup generator. The LINE pin is connected to Vcc through a 330kΩ resistor, and after a short time it rises above 1.25V, as expected. So in principle all startup conditions for the L6591 should be fulfilled.
After that, the SS pin charges to 2V, VREF reaches 5V, and then the IC repeatedly restarts. We are not sure why this happens.
Is there any additional documentation available that explains the startup sequence in more detail? The information in the datasheet is not completely clear to us. Unfortunately, we currently have no evaluation board available in our country, so we cannot perform comparison measurements on a known-working design.
Does anyone have experience with the L6591 startup procedure and could tell us which signals or conditions we should definitely check?
Thank you!
