TPS54680-EP: Synchronous Buck

Brian Cortes

Prodigy 10 points

Part Number: TPS54680-EP
Other Parts Discussed in Thread: TPS62810M, TPS54380, TPS628511, TPS628501

Hello,

Wondering if there's a minimum load requirement for the TPS54680-EP?

The plots show efficiency down to 0.5A, but will it operate with a lower load such as 100mA?

11 months ago

0 Chris Glaser 11 months ago

TI__Guru*** 147210 points

Hi,

There is no minimum load for this device. The efficiency plots stop at 0.5A, since the efficiency drops off sharply below that level. You can see figures 13 and 14 and 15 show no load behavior, for example.

We also have the TPS62810M, which operates down to -55C. Would that work for you, or do you need the VID, etc?

Thanks,

Chris

0 Brian Cortes 11 months ago in reply to Chris Glaser

Prodigy 10 points

Thanks Chris,

We can linearly extrapolate the efficiency.

We were actually using the TPS54380, but this device is now obsolete and we decided to use the TPS54680-EP. Based on the low efficiency, maybe there's a better part that we could have used. Possibly even a drop-in replacement?

0 Chris Glaser 11 months ago in reply to Brian Cortes

TI__Guru*** 147210 points

Ah, were you using the TPS54680-EP as an alternate to TPS54380? Do you need the -EP or -55C operation? If not, there are much better, newer options to look at that won't go obsolete for a while. What is your Vin, Vout, Iout, and any features needed?

TPS54380 is a 20 year old device in a leaded package.

Chris

0 Brian Cortes 11 months ago in reply to Chris Glaser

Prodigy 10 points

We initially thought that using the TPS54680-EP as an alternate was best since we already had this part in our design.

Now we're realizing that the efficiency at the loads we need (less than 0.65A) is not great. We don't need the -EP rated version.

Vin is 5V, Vout is 1.28V and Iout for one device would be100mA and for the other would be 650mA.

0 Chris Glaser 11 months ago in reply to Brian Cortes

TI__Guru*** 147210 points

Thanks for explaining.

Would TPS628511 (or TPS628501) work for you? We also have a power module version, with inductor integrated, releasing soon: https://www.ti.com/lit/ug/slvucp5/slvucp5.pdf

Chris

0 Brian Cortes 11 months ago in reply to Chris Glaser

Prodigy 10 points

Hi Chris,

Thank you for the quick responses, really appreciate the support.

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

Power management

Power management forum

TPS54680-EP: Synchronous Buck