TEA1716T PFC issue

[bert]

Hello

I am having trouble to get the PFC function working for the TEA1716T controller.

I disconnected the half bridge and LLC transformer to debug for PFC only, Put 1.5V on pin SSHBC/EN and 25V on SUPIC.

Upon the startup of the system (applying mains voltage to the circuit) the PFC controller starts reguating towards 400V, but once this level is reached, it stops regulating and the voltage drops again.

CH1 = GATEPFC, CH2 = VdrainPFC, CH3 = HVOUT, CH4 = COMPPFC

CH1 = GATEPFC, CH2 = VdrainPFC, CH3 = HVOUT, CH4 = SNSBOOST

Any help or pointers would be greatly appreciated

[bert]

Hello

I have found the issue. The pin SNSBURST was below 3.5V which causes the controller to stop switching. When modifying the resistor divider from SNSFB-SNSBURST, the controller continued switching.

[JozefKozon]

Hello Bert, I am checking an application note AN11179. There on the page 120 is described PFC use only. Please see the file attached. Have you connected the pin RCPROT to the ground, to disable protection timer? Can you make sure that the supply voltage on the PFC input is always above 70V. Can you send me your schematic of the connection of the PFC only?