AVR Freaks

Note: when I mean shoot through I dont mean the shoot through of the main mosfet bridge. I mean the shoot through of the isolated supply voltage of the gate driver.As it is an amplification stage I dont want to use timing or logic circutary to prevent shootthrough.

The timing and logic in the gate driver is to prevent the control signals of the seperate mosfets to prevent bridge shoot through of the main power bridge.

Does your configuration have a totem pole with discrete mosfets or a complete package such as ACPL332J.

You need 1 totem pole for turn on resistor and 1 totem pole for turn off resistor.
Does your configuration have 1 totem pole for both.

If so how can you overcome the shoot through of totem pole mosfets. The concrete Ics opto+totem pole have 1 totem output. So Ron must be equal to Roff. (no seperate values possible)

optos can not be used for high frequency, they have high capacitance and coupling. they also have very high delay.I use Silicon on insulator transformers. But anyhow the mosfet totem pole is not suitable for high power gate drive (I>4A and Irms>1A)

Best one has 400ns delay, and aging with time. capacitive coupling is always there, shielding is also limited.
Why use optos I used HCPL4502 and 4503 over 10 years.
I swicthed to SOI technology adum4223 or si8234. far far better . Life does goes on.

bobgardner: I thought about the paralell capacitor idea. But in general as it is a very high frequency gate drive (x20 more than an audio amp) (I assume that audio amps are in range of 48Khz) . Any capacitor on the gate path detroys the balance, speed and the most important the turn off speed.
The main problem, the hardest to solve is the turn off part. I cam optimize the turn on part with many instruments. But a fast oand ossi-free reliable turn off at frequencies above 500Khz is really hard and your suggestion to add a paralel cap to Rg makes it harder.

Lets think abaout the turned off stage . We assume that the device is turned off with your caps//rg . Now you have a paralell capacitance to the mosfet gate capacitance. Knowing that your cap is fully charged // to the charged mosfet capacitor. we will have hard time to discharge both in 50-100ns. But i must think the alternative that if I have seperate ron and roff . How will it fit if I paralel a speedup-cap for the Ron, but not the Roff.

For this case capspeedup//ron you have a capacitive divider cspeedup and cmosfet. It meens mosfet sees a voltage of cspeed/(cspeed+cmosfet) for the first moments of the applied voltage. That can also controversly decrease the gate speed. (if we talk abaout very high speed gate drives). In consequence your speedup range is only available for low-mid speed gate drives. above 500khz your speed-up cap behaves as a slow down cap. So imho it depends on the speed range at which working point you are driving