I am designing a 25A 12V Variable SMPS, offline.
Output voltage is ok, but the ripple is about 35 mV peak to peak triangular, with spikes of about 300 mV on either side, in sync with MOSFET Switching.
How can I arrest these 300 mV sharp spikes?
Details of ckt are :
Half bridge topology, IRF450P MOSFETs, 3825 PWM Controller driving a ferrite core trans 1:1:1.
Transformer & Inductor with 2 separate planar cores.
Primary transformer snubber of 51 Ohms & 1000 pF.
MBR3060 diodes (2 devices) for output, with 10kPF & 10 Ohms snubber across each diode.
I have changed the freq fm 40 kHz to 100 kHz, tinkered around with doubling / halving both the IRF450 / MBR3060 Snubber caps & resistors, with no change in the spikes.
Can someone help me?
Output voltage is ok, but the ripple is about 35 mV peak to peak triangular, with spikes of about 300 mV on either side, in sync with MOSFET Switching.
How can I arrest these 300 mV sharp spikes?
Details of ckt are :
Half bridge topology, IRF450P MOSFETs, 3825 PWM Controller driving a ferrite core trans 1:1:1.
Transformer & Inductor with 2 separate planar cores.
Primary transformer snubber of 51 Ohms & 1000 pF.
MBR3060 diodes (2 devices) for output, with 10kPF & 10 Ohms snubber across each diode.
I have changed the freq fm 40 kHz to 100 kHz, tinkered around with doubling / halving both the IRF450 / MBR3060 Snubber caps & resistors, with no change in the spikes.
Can someone help me?