TPS54231: Battery Powered Application

Philip Wooldridge

Part Number: TPS54231
Other Parts Discussed in Thread: TPS62140

Hi,

I have a battery powered application using a sealed lead acid battery. I need a 3.3V power converter for the battery output, so the input range needs to include potentially a 8V float voltage. I need 2 amp output when the board is in active mode. In sleep mode I of course would like to have the lowest possible current draw. The TPS54321D fulfills most of these requirements, but I would wish for a lower operating current while in sleep mode than the 75uA draw by the TPS54321D. Is there a solution with less operating current? I have a load in sleep mode less than 60nA. If a suitable power converter does not exist, I am toying with the idea of having 2 3.3V converters, one for sleep mode and one for active mode. I would disable the TPS54231 in sleep mode. This requires a converter with lower output current, maybe 10mA or there abouts and of course a very low operating current. The 2 outputs would be OR'd together with a FET based OR'ing device.

Any help with these requirements will be appreciated. I have tried parametric solutions but am never sure that I have not inadvertently eliminated viable options.

Thanks, Phil

over 5 years ago

0 JohnTucker over 5 years ago

TI__Guru**** 191445 points

Phil,

What is the minimum and maximum input voltage?

0 Philip Wooldridge over 5 years ago in reply to JohnTucker

Prodigy 45 points

I tried to answer your question from the E2E support page, but get a message saying my response was not sent because I don't have permission to send to that list. I need to ask for permission. I do not know how to do that.

Hi John, The battery charging circuit varies the charge voltage applied over temperature. Worst case is 6.8V. The low end fully charged voltage can be 5.5V, although the battery still can deliver charge down to 4.5V. So, 4.5V to 6.8V.

0 JohnTucker over 5 years ago in reply to Philip Wooldridge

TI__Guru**** 191445 points

Phil,

I would probably look at TPS62140 series. PS62142 is internally set for 3.3 V operation. 50 nA load is extremely small. The FB resistor divider will draw many times that current. At 5o nA, you may want to disable the converter completely.

0 Philip Wooldridge over 5 years ago in reply to JohnTucker

Prodigy 45 points

I had a similar idea. I only need the 2 amps for a RF xcvr. I could run the uC with a power converter that produced 100mA. Is there a very low operating current solution at the lower current?

The 17uA quiescent current is a pretty big improvement. Thanks.

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TPS54231: Battery Powered Application