UCC21710: No output at gate driver

keviv

Prodigy 80 points

Part Number: UCC21710

Tool/software:

Hi,

In my project the IN+ and IN- pins are fed with complementary pulses but there is no Output coming at OutH/L

the Vgs is clampled to -5V

in my design Vdd is 20v and Vee is -5 V

9 months ago

0 Sasikala Thangam 9 months ago

TI__Expert 8265 points

Hi Keviv,

Can you please check FLT, RDY pin voltage before applying IN+, IN- inputs and also during applying IN+ and IN- Inputs?

If FLT is low, please check OC pin voltage and share the waveforms.

If RDY is low, Please check VCC, VDD and VEE voltages and share the waveforms.

Thanks

Sasi

0 keviv 9 months ago in reply to Sasikala Thangam

Prodigy 80 points

Hi Sasikala,

This problem got resolved when i powered the bus voltage 400V.

i was checking the pulses with deenergized bus.

but i dont know the principle behind this.

Thanks

Keviv

0 Sasikala Thangam 9 months ago in reply to keviv

TI__Expert 8265 points

Hi Keviv,

Very likely, the OC was triggered to create FLT. Good to know that it is working now.

0 keviv 9 months ago in reply to Sasikala Thangam

Prodigy 80 points

Hi Sasi,

If there is no Bus voltage, will it result in triggering OC ?

thanks

keviv

0 Sasikala Thangam 9 months ago in reply to keviv

TI__Expert 8265 points

Hi Keviv,

Not necessarily, it depends up on how the OC is implemented.

If the OC implemented as DESAT,

When the FET is conducting then the OC/DESAT charging current is passed through the conducting power FET. If the FET is not conducting (DESAT/ high voltage across) , then it will not have discharge path so will cause the OC capacitor to charge and cause OC FLT.

Thanks

Sasi

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UCC21710: No output at gate driver