LMZM33606: Can SYNC clock be applied to SYNC/MODE pin of LMZM33606 before the LMZM is powered up?

Kazuya Nakai59

Part Number: LMZM33606

One of my customers is considering using LMZM33606 for their new products.

They wants to send SYNC clock(5V-0V swing) to SYNC/MODE pin of LMZM33606 before the LMZM is powered up because the SYNC clock generator is powered up earier than the LMZM.

I can see that the maximum voltage of SYNC/MODE pin is 5.5V in the device datasheet. So I think any diode is not inserted from SYNC/MODE to VCC.

Is my understanding correct and is it no problem to apply 5V-0V clock to SYNC/MODE pin of LMZM33606 before the LMZM is powered up?

Your reply would be much appreciated.

Best regards,

Kazuya.

over 5 years ago

0 Jimmy Hua over 5 years ago

TI__Guru 50120 points

Hi Kazuya,

Yes an external SYNC clock can be present before the device is powered on. The IC will ignore the SYNC during softstart. Once the converter stabilizes it will transition to the external SYNC signal.

Regards,

Jimmy

0 Kazuya Nakai59 over 5 years ago in reply to Jimmy Hua

Guru 21525 points

Hello Jimmy,

Thank you very much for your reply.

It is very helpful for the customer and me.

Thank you again and best regards,

Kazuya.

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LMZM33606: Can SYNC clock be applied to SYNC/MODE pin of LMZM33606 before the LMZM is powered up?