CGD1200HB2P-BM2 is dropping gate pulses

Sarah

I am testing the CGD1200HB2P-BM2 gate drive board. I am supplying 0-5V input signals and 12V power to the board, however the output is missing pulses (example image is attached) or even getting stuck at high or low rail (-5V or + 20V).

No fault lights are tripping. The overcurrent protection pin is connected to the positive side of the half bridge (CAS120M12BM2). There is no voltage applied to the half bridge during this test (Vds = 0). Reset is pulled low. PS-DIS and PWM-EN are pulled high (5V).

Why are the gate pulses being missed? Can Wolfspeed make a recommendation to correct this?

Thank you.

AustinC

Hi Sarah,

I believe the issue is due to the PWM input on the gate driver expecting a differential 5 V signal rather than a singled-ended, 0 V - 5 V signal. A differential signal will provide +5 V between HS-P & HS-N during the on-state and -5 V between HS-P & HS-N during the off-state. The easiest way to achieve the correct signaling is by using Wolfspeed's companion differential transceiver board (CGD12HB00D), which can be purchased through various distributors. Here is a link to the product on Digi-Key:

https://www.digikey.com/en/products/detail/wolfspeed-inc/CGD12HB00D/10248982

Best Regards,

Austin C.

Sarah

Thanks! Yes this was definitely the problem.