Styx said:
The FET's you are using, do they have intrinsic diode?
the CCT you are showing has no free-wheel diodes
MTP2955:
Designed for low voltage, high
speed switching applications in power supplies, converters and power
motor controls, these devices are particularly well suited for bridge
circuits where diode speed and commutating safe operating areas are
critical and offer additional safety margin against unexpected voltage
transients.
• Avalanche Energy Specified
• IDSS and VDS(on) Specified at Elevated Temperature
IRFZ44N
Advanced HEXFET® Power MOSFETs from International
Rectifier utilize advanced processing techniques to achieve
extremely low on-resistance per silicon area. This benefit,
combined with the fast switching speed and ruggedized
device design that HEXFET power MOSFETs are well
known for, provides the designer with an extremely efficient
and reliable device for use in a wide variety of applications.