Tool/software:
In my full bridge converter, the LM5045 SR outputs are toggling even though there is no PWM output signal (HO/LO); this only occurs briefly, during a one time hiccup that occurs after startup. Essentially the DC output voltage of the converter comes up twice: the first time it overshoots by 10V (reaches 55V vs 45V setpoint) then drops to 0V in about 200usec, then comes up a 2nd time smoothly, with no overshoot, and stabilizes /runs normally at 45V (proper DC output), so the cct is actually regulating properly. I think the FB loop is causing this hiccup and needs to be tuned; but aside from that, the bigger problem is the hiccup of the output; 50V drops to 0 in 200usec and with about 500uF load capacitance, this requires a very large current. At the first startup, as soon as the output overshoots, the PWM (LM5045 HO/LO) immediately stops. Then both SR outputs of the LM5045 start toggling in unison / in phase at the designed sw freq (330kHz) while the PWM HO/LO outputs remain stopped; note at this time both SR1 and SR2 are in phase with each other (they have the exact same waveform) so they are driving all the sync MOSFETs together and discharging / shorting the output (during the hiccup) which, aside from conducting excessive current, are being subjected to very high voltage pulses - as high as 175V, when SR's toggle off.
Do you know what causes the LM5045 to enter this mode of operation? I don't see anything in the data sheet to help me in this regard.
