TPS826951: Bucks understanding if voltage goes below the Vout

MohammedAl-Amin

Part Number: TPS826951
Other Parts Discussed in Thread: TPS63051, TPS62698, TLV733P, TPS82740B

Hello,

I have sensitive components which have a voltage requirement between 3V to 3.6V. But my battery runs at 3V to 4.2V, I was thinking of using an LDO or Buck converter.

But I was wondering with TPS826951 which is a buck converter if the voltage goes below the Vout would the Buck converter disconnect?

I was hoping if Vout is 3.3V that if Vin goes down to 3V that Vout can go to 3V and not disconnect.

Would this idea work?

over 7 years ago

0 Chris Glaser over 7 years ago

TI__Guru*** 142750 points

Please see the 100% mode section on page 19 of the D/S.

As well, a buck-boost converter like TPS63051 would keep Vout regulated at 3.3V even when Vin is at 3V.

Finally, the TPS826951 is a 2.5Vout device. The 3Vout version is TPS62698.

0 MohammedAl-Amin over 7 years ago in reply to Chris Glaser

Intellectual 540 points

Hello,

We needed a converter which is as small as possible which would just clamp the voltage from reaching over 3.6V and be ultra low power consumption but we don't mind the voltage to vary during 3V to 3.6V the other option was TLV733P.

to be a much smaller option.

0 Chris Glaser over 7 years ago in reply to MohammedAl-Amin

TI__Guru*** 142750 points

Understood. Sometimes customers need the boost functionality to keep Vout above a higher minimum and to overcome IR drops (in the battery impedance, PCB trace, etc.) in their system.

The TPS82740B is an equally small buck module with much lower Iq. It cannot deliver as much output current though.

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TPS826951: Bucks understanding if voltage goes below the Vout