UCC27524A: UCC27524A weak noise-immunity ability

Hi Robin,

Thanks for reaching out on UCC27524A! Im an apps eng with this device.

It looks like theres some noise on the input as well as some ground bounding (see the switchnode will help determine if ground bounce is also an issue) from the switch node that may be producing the issue. For example, the device seems to be switching ok in the first 2 cycles. Then at the start of the 3rd cycle there is a dip that spikes the input that puts the output in a high impedance state. In the middle of the third cycle the input spikes high and the output resumes. Its possible that the noisey spikes are causing the input signal to disrupt the threshold. In this case the proper input filter should be applied to limit these spikes.

When comparing UCC27524A and TC4424 I see the input structure is different so I would like to take a look at the schematic to see what has changed/remained, can you show this?

Hi Jeffrey,

Please refer to the schematic as below. before the INA and INB, there is the R60=10ohm, R61=5.1kohm, and before R60, there is a R=510ohm, then connected to the C2000 GPIO pin.

the C61 is a cap socket, but the customer now don't install this. 

because this project is a customer mass products production, and no issue with TC4424. so the customer prefer we can provide a drop-in part, which is even no need to change the resistors, but can provide the same immunity ability.

by the way, can you show me the difference between TC4424 and UCC27524A of the input structure? and what is the related specifications of the gate redriver input noise immunity ability?

Regards

Robin Liu

Hi Robin,

Thanks for the detailed reply, and reaching out offline. Let me take a look with ritesh and update you on this thread asap.

Thanks,