LM5025C: OCP hiccup frequency is different

user5230569

Prodigy 120 points

Part Number: LM5025C

Hi TI:

Why when I use LM5025C CS2 PIN for current limit, the hiccup frequency changed ...

First I short output, then increase input voltage slowly. I found hiccup frequency increased immediately.

C2 is SR mos stress, C3 is SS voltage.

over 4 years ago

0 Aidan Davidson1 over 4 years ago

TI__Intellectual 2640 points

Hello!

Thank you for reaching out and for your interest in the LM5025C! A few questions:

1. Are you ramping the input voltage from 0V?

2. At what input voltage do you observe these events?

a. Hiccup begins

b. Hiccup frequency increases

3. Are you able to provide corresponding output voltage waveform?

Thanks again for getting in touch, I look forward to talking more soon!

Aidan Davidson

0 user5230569 over 4 years ago in reply to Aidan Davidson1

Prodigy 120 points

Hi Aidan:

Thank you for reply.

I think I know the reason why when I ramp the input, the hiccup frequency will increase.

Because my additional circuit led to ic vcc voltage drop at higher input, the ic restart.

Thanks again

0 Aidan Davidson1 over 4 years ago in reply to user5230569

TI__Intellectual 2640 points

Hello!

Since it seems you've resolved your issue, I'm closing this thread. If you have any further questions or need any additional help, please open a new thread.

Thanks again for reaching out!

Aidan

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LM5025C: OCP hiccup frequency is different