TPS62480: operation with single inductor - phase

glen english

Part Number: TPS62480

I have 6x power supplies on a board, and want to use the same chip (TPS62480)

All supplies are 1amp max except one which is 6A max.

Since the 62480 goes into single phase mode at < 1.7A approx, for the low current supplies, can I NOT place the 2nd phase inductor ?, will the control system be happy without that inductor- as except for initially filling the capacitors, it will never turn on the 2nd stage. (and I will use two phases on the high current supply)

I was going to try a WEBBENCH but it does not allow me to have different inductors- that is I tried to create custom inductor with 10000000 ohms Rs (ie open circuit) but it applied the resistance to both phase inductors. The inductors are ganged. it might be useful to be able to vary the two of them indpenendently to assess mathcing issues.

thanks

glen

over 4 years ago

0 Dorian Brillet de Cande over 4 years ago

TI__Genius 14856 points

Hello Glen,

In theory you can, I would not recommend to do this though because this is outside of specifications.

Also,it wasn't tested how system is behaving if TPS62480 has only one inductor and if for any reason load is higher than expected (>1.7A) or your system sees a shortcut.

In this case, functionality is not then guaranteed.

You can try this scenario on TPS62480EVM to validate your system's requirements.

Thanks a lot!

Regards,

Dorian

0 Dorian Brillet de Cande over 4 years ago in reply to Dorian Brillet de Cande

TI__Genius 14856 points

Hello Glen,

Also if high Cout and fast start up ramps are used then current in inductor could be over 1.7A and reach untested conditions.

Thank you,

Dorian

0 glen english over 4 years ago in reply to Dorian Brillet de Cande

Prodigy 20 points

Hi Dorian

thank you for both of your replies.

OK. Understood. Yes the EVM is most likely the best option, startup is the issue.

best regards

Power management

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TPS62480: operation with single inductor - phase