design of Desaturation circuit

zahra Amjadi

Other Parts Discussed in Thread: UCC21750

Please, let me know, how can design a desaturation circuit for IGBT or Mosfet. I need an internal design for Desat. the circuit inside of IGBT or MOSFET.

I know desat. the circuit includes of Comparator and logical circuit but I don't know the detail of desat. circuit

over 4 years ago

0 John Wallace1 over 4 years ago

TI__Mastermind 38190 points

Hi Zahra,

Thanks for the inquiry. I am not familiar with desaturation circuits. I did find an application note in the link below and a gate driver handbook.

0 zahra Amjadi over 4 years ago in reply to John Wallace1

Prodigy 50 points

I saw before these files but I need the interior design of the Desaturation circuit, not the circuit between the desat. circuit pin until IGBT or SIC.

0 John Wallace1 over 4 years ago in reply to zahra Amjadi

TI__Mastermind 38190 points

Hi Zahra,

I am going to reassign this thread to our gate drivers team. Many of their products have integrated desaturation protection.

0 Don Dapkus over 4 years ago in reply to John Wallace1

TI__Guru**** 189401 points

Hi, Zahra,

We have several devices that have built-in DESAT protection, like UCC21750 for example.

Would these work for your application?

We also have a document that describes how we built an external DESAT protection circuitry. Please see 2.3.2.2 Short Circuit Detection of this TI reference design.

https://www.ti.com/tool/TIDA-01605

Let us know if you can just use one of our gate drivers with DESAT protection. We've taken all the work out of it for you!

0 zahra Amjadi over 4 years ago in reply to Don Dapkus

Prodigy 50 points

Thank you, I sent the email to you but I didn't receive response.

This document is so good and thanks to you for your fast response.

I have some question:

on page 9: 1)as I showed below, SIC or IGBT should connect to Drain, source, and Gate of Switching?

2) what is -4VB? the meaning should connect to -4 V source voltage?

3) VCC5V? the meaning connect to 5V source voltage?

4) the Vds threshold for protection is approximately 10.3 V? why? because our reference voltage is 3V or sense Voltage but how to convert to 10.3 V

0 Don Dapkus over 4 years ago in reply to zahra Amjadi

TI__Guru**** 189401 points

Hi, Zahra,

1. Yes, connect gate to G2, drain/collector to D2, and source/emitter to S2

2. Yes, the gate driver circuit runs off 15V and -4V, which is common for IGBT/SiC

3. Yes, VCC5V means 5V supply

4. You can change the threshold level by modifying the voltage that U9 outputs by modifying the resistor divider formed by R24 and R28.

Let us know if you have further questions.

0 zahra Amjadi over 4 years ago in reply to Don Dapkus

Prodigy 50 points

Please, let me know, this design is not design of the inside Desat model of Gate driver, is it correct? because I need design of Desat model inside of Gate driver.

0 Don Dapkus over 4 years ago in reply to zahra Amjadi

TI__Guru**** 189401 points

Hi, Zahra, The concept is the same for both, but the IC implementation is a little bit different. We do not disclose the internal designs of our devices.

0 zahra Amjadi over 4 years ago

Prodigy 50 points

I need to check my desat design circuit for the gate driver of IGBT or SIC.

0 Don Dapkus over 4 years ago in reply to zahra Amjadi

TI__Guru**** 189401 points

Hi, Zahra,

I recommend checking it against the reference design I sent earlier.

If you have further questions, please click on the "Ask a related question" button on the upper right side of your screen.

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design of Desaturation circuit