LM7480-Q1: Power management forum

Lim Yoke Peir

Part Number: LM7480-Q1

Hi,

Discovered an issue when evaluating LM74801 which is configured as Common source config with cut off mode.

Noticed that with a pulse of 30V (100ms pulse) on top of 13V, causes no output of the LM74801 after the pulse back to 13V. Found that the Hgate kept oscillating and didnt turn on as expected.

However no similar issue observed with 30Vpulse with 70ms duration on top of 13V.

Repeating the test with Vin of 20V (100ms pulse) on top of 13V, observed that the LM74801 had some oscillation on Hgate before it recovered.

Would like to have private chat before posting any scope shot and schematic.

over 3 years ago

0 Praveen GD over 3 years ago

TI__Guru 57737 points

Hi Lim,

Thanks for reaching out to us.

We will definitely need to look at schematics and waveforms to understand more about this issue.

Like you said, we can continue our discussion in private chat if you want to keep the content shared confidential. I am sending you a friend request, please accept it.

0 Lim Yoke Peir over 3 years ago in reply to Praveen GD

Prodigy 40 points

Hi Praveen,

I have accepted the friend request and sent you few messages.

0 Praveen GD over 3 years ago in reply to Lim Yoke Peir

TI__Guru 57737 points

Hi Lim,

Thanks. Let's continue our discussion in private chat.