TPS62746: 3.3V version of this buck converter (or a similar buck converter)

Dolf Andringa

Part Number: TPS62746
Other Parts Discussed in Thread: TPS62840

The part selector website is a bit unclear because it states that this buckconverter has a Vout max of 3.3, but when checking the datasheet it is actually only selectable as 1.2 or 1.8V. So is there a version of this IC that has a 3.3V output?
I am looking for the following:

3.3V Vout
2.6-5.5V Vin
Iout max 300mA (between 100 and 200mA is fine too)
Iq typ < 1uA
An enable pin that connects Vin to an output pin which can be used to measure the battery voltage on an ADC with voltage divider, but only when the enable pin is switched on.

The TPS62746 ticks all the boxes except that it only supplies 1.8 or 1.2V output.

over 4 years ago

0 Stefano Panaro over 4 years ago

TI__Expert 7685 points

Hello Dolf,

Thank you for your question.

You are right, as the datasheet states, TPS62746 can only supply 1.2V and 1.8V output.

Unfortunately I am not aware of any device of our catalogue that respect all of your specs (in particular the VINSW pin).

The TPS62840 is a high-efficiency step-down converter with ultra-low operating quiescent current of typically 60 nA, optimized to extend battery life. However it lacks the VINSW feature. Referring to its datasheet:

Would it be possible for you to consider any additional elements (for example an external P-Mosfet) to implement the additional feature?

Thank you,

Stefano

All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

0 Dolf Andringa over 4 years ago in reply to Stefano Panaro

Prodigy 180 points

Yes I could indeed do that, but at that point the TPS6284x is definitely not the only option, and requiring a separate p-channel mosfet is quite a big disadvantage.

0 Stefano Panaro over 4 years ago in reply to Dolf Andringa

TI__Expert 7685 points

Hello Dolf,

Yes, I see your point.

Sorry if I wasn't able to help you more.

Thank you again for your question,

Stefano

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TPS62746: 3.3V version of this buck converter (or a similar buck converter)