LM5026: the difference between high-end clamp and low-end clamp using LM5026

Sophia Yao

Part Number: LM5026

Hi team,

When LM5026 is used for high-end clamp, the driving signal of auxiliary MOSFET has a 60 ms constant high voltage at startup. The schematic and test waveform are as below. Is this phenomenon normal? Because when using 5026 as low-end clamp, I can't see the 60 ms high voltage at startup. So can you please do the same test with EVM and then explain the difference between high-end and low-endclamp phenomenon?

Thanks very much.

best regards,

Sophia

over 6 years ago

0 John Griffin1 over 6 years ago

TI__Mastermind 34465 points

Hello Sophia,

You should put this request through your local TI sales office.

Request that an AE be assigned to this problem and describe the issue and the testing that you require on the LM5026EVAL.

Regards

John

0 Sophia Yao over 6 years ago in reply to John Griffin1

TI__Prodigy 701 points

Hi John,

thanks for your reply. do you think this phenomenon is related to dead time of LM5026?

0 Peter Meaney over 6 years ago in reply to Sophia Yao

TI__Mastermind 31580 points

Hi Sophia,

I think the behavior makes sense. When the device is configured for high side clamp the AUX output goes high as this is the OFF state for the drive. When configured for low side clamp the AUX output is low which is the OFF state for the low side configuration.

Regards

Peter

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LM5026: the difference between high-end clamp and low-end clamp using LM5026