Other Parts Discussed in Thread: UCC21732-Q1, , UCC21750, ISO5452-Q1, UCC21710-Q1
Hello all,
I'm planning to use the UCC21750-Q1 for my Gate driver for an inverter. I've been reading the documentation for some time. I've been trying to correlate with the reference design of the UCC21732-Q1.
1. The UCC21750-Q1 has DESAT pin as opposed to a OC pin on the UCC21732-Q1. Under the application information of the UCC21750-Q1 as attached here
The data sheet recommends the use of a schottky diode for the negative voltage damage suppression and zener for the positive voltage protection. There isn't any schematic for the same given. I was wondering if I could alternately use a schottky both for negative and positive voltage protection. That is, Schottky to COM for negative voltage protection and Schottky to VDD for positive voltage protection. Please tell me if this can be done and if there is something I'm missing why the datasheet clearly states the recommended use of Schottky+Zener and not Schottky+ Schottky
Also, if I were to use Schottky Diodes, which would be the key parameters to aim for? Currently, I'm looking at reverse breakdown greater than my bipolar voltage supply, but I'm not sure how to arrive at the other parameters. Could you please help on this?
2. On the above, just to be sure could you tell me if those three conditions are applicable only if the DESAT pin is not used. I believe not as if I were to use the DESAT pin I will need the clamp protection that these diodes would provide.
3. Do I need to clamp the Gate pin (after Rgon & Rg0ff) to VDD and VEE for this design? The datasheet suggests internal diodes upto VDD only. But since I'm planning to use a Bipolar supply do I need to do it externally for the Negative voltage?
Thank you!