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UCC27712: High current full-bridge IGBT driver transients.

Part Number: UCC27712

Hi,

I'm working on a high current circuit which uses two drivers(UCC27712) to control a full-bridge IGBT module(MIEB101H1200EH).  The drivers are powered by a 12V source and the full-bridge is powered by a 48V 62 amp source with a resistance load of 1 ohm . At a PWM frequency of 490 Hz the circuit works but there is a transient component in the transition between pulses that concerns me. Below I included a picture of the schematic and pictures of the signal(high-side of load referenced to ground) as I stepped the duty cycle through 20%, 40%, 60%, and 80%. If you have any insight into causes of this issue I would appreciate your input. 

Thank you 

20% Duty Cycle

40% Duty Cycle

60% Duty Cycle

80% Duty Cycle

  • Hello Kyler,

    Thank you for the interest in the UCC27712.

    Since you are operating a full bridge, can you confirm the signal you are showing on the scope? I assume it is the switch node of one of the half bridge stages. I also would assume you are driving the high side of one half bridge leg at the same time as the low side of the other half bridge. Please confirm.

    Can you show the two different half bridge switch nodes, HS10 and HS20 ? Also is the 1 Ohm load resistance from HS10 to HS20? I would confirm that the gate driver outputs are as you expect based on the driver inputs, and that the timing (including dead time) is as you expect.

    Regards,