NTC of CCB021M12FM3

JeremyZhang

Hi Brett,

Thanks for your kindly support, our customers using NTC for temperature sampling of CCB021M12FM3, do they need to add capacitive isolation or optical isolation?

Best Regards,

Jeremy

TBhatia

Hello, thank you for your message. A member of our technical team is looking into your questions and we will respond shortly. 

BrettSparkman

Hello Jeremy,

The NTC is on an isolated copper island inside the power module. However, an isolation stage is still recommended due to proximity to other pins on the PCB.

Our CGD1700HB2M-UNA gate driver, recommended for WolfPACK products, utilizes an isolated and low-side referenced using the secondary-side TI UCC21710 analog input, not requiring any additional isolation ICs. You can find this in the schematic using the "RTD-ISO" net.

As this gate driver was implemented as a standalone PCB, the NTC connection must be made thru a 2-pin header and cabling that connects to a 2-pin header on the PCB the WolfPACK module is inserted into. This is implemented on WolfPACK Evaluation Kits.

https://www.wolfspeed.com/cgd1700hb2m-una/

Thanks,

Brett

JeremyZhang

 Hi Brett, thanks for your patient and hard work, could we provide the insulation level between NTC and die inside the module? Basic insulation, functional insulation or reinforced insulation? Our customers have consideration because they use controller IC for thermal measurement is on low voltage side, however the die inside power module is on high voltage side, NTC is on the low voltage side. Controller IC between high voltage and low voltage is 2500Vac, 1min.

I really appreciate your help!

Jeremy

BrettSparkman

Hello Jeremy,

Due to the uncertainty of potential conductive paths during a hard device failure, the NTC should be considered as a functional isolation.

Thanks,

Brett

TBhatia

Hi, I hope that this answered your question. I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.