CSD87355Q5D: VIN will be switched between 12V and 5V when in different system power state

Tiger Yeh

Part Number: CSD87355Q5D
Other Parts Discussed in Thread: TPS51219

Hi,

If my application will switch different Vin between 12V in 5V, is there any risk and side effect that have to consider in design?

In S0 power state, VIN will be 12V.

In S5 sleep power state, VIN will be 5V.

P.S: The PWM controller is TPS51219.

Please advise!

Thanks and Best regards,

Tiger

over 1 year ago

0 John Wallace1 over 1 year ago

TI__Mastermind 34750 points

Hello Tiger,

Thanks for the inquiry. There should be no risk or side effects from the power block perspective. When switching the input voltage from 12V to 5V, the duty cycle will increase and there may be a transient on the output voltage. Similarly, when switching from 5V back up to 12V, the duty cycle will decrease and there may also be a transient on the output voltage. You should also make sure that the controller can support the min/max duty cycle requirements with 12V and 5V input. I'm going to reassign this thread to the controller apps team to get their input.

Best Regards,

John Wallace

TI FET Applications

0 Tiger Yeh over 1 year ago in reply to John Wallace1

TI__Expert 5025 points

Thank you very much! John

The output is 1.25V. Suppose duty cycle is no problem.

Best regards,

Tiger

+1 John Wallace1 over 1 year ago in reply to Tiger Yeh

TI__Mastermind 34750 points

Hi Tiger,

I don't any issues with changing the input voltage. I would recommend testing and capturing the switching waveforms during the transitions.

Best Regards,

John

0 Tiger Yeh over 1 year ago in reply to John Wallace1

TI__Expert 5025 points

Thank you! John

Have a nice day.

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CSD87355Q5D: VIN will be switched between 12V and 5V when in different system power state