CC2540 and step down converter for Li-ion battery

Cedric Saab

Other Parts Discussed in Thread: TPS62730, CC2540, TPS62065, TPS62230, TPS62120, TPS780

Hello all,

I am currently working on a battery powered product using the CC2540. I would like to optimize the power consumption. It is recommended in the datasheet to use the TPS62730 step down converter. However, the battery used in my product is a Li-ion battery with a maximum voltage around 4,2V. The TPS62730 cannot be used as it allows input voltage from 1,9V to 3,9V and an absolute maximum voltage of 4,2V. Do you have any solution for optimizing the consumption? Is there an other device working with such batteries?

Thank you for your help.

Best regards

over 13 years ago

0 Gijs de Graaf over 13 years ago

Intellectual 415 points

Hello,

I am also facing this problem. The product which I'm developing is powered by 3XAA batteries which gives me an output voltage of 4.5V.

At the moment I'm looking at the TPS62065 step down converter but I don't know if this is the best option for me (and maybe Cedric).

Also thanks.

BR,

Gijs

0 Markus Matzberger over 13 years ago in reply to Gijs de Graaf

TI__Prodigy 30 points

I recommend to use:

either

http://www.ti.com/product/tps62230: 22uA, 3MHz step down converter series

or this one with lower Iq:

http://www.ti.com/product/tps62120: 11uA, 75mA step down converter, coming in SOT23 or 2x2 SON package

Both converters are used in low power wireless applications and feature low output voltage ripple.

Cheers

0 Jan Althaus over 13 years ago in reply to Markus Matzberger

Prodigy 90 points

Hi Markus,

could you please give some context as to why the TPS76933 was chosen for the USB key reference design? Both of the converters you listed look like they could have been used instead. What am I missing?

Thanks,
Jan

0 Daniel A. over 13 years ago in reply to Jan Althaus

Intellectual 360 points

Hi Jan

I wonder the same.. did you find an answer already?

I came across this IC TPS780 which looks pretty good to power the CC2540 from a LiPo battery. Have you made any progress?

Regards

Daniel

0 Jose C over 12 years ago in reply to Jan Althaus

Prodigy 10 points

Hi Jan,

The TPS76933 was chosen (most likely) because its output is 3.3V. Since USB D+ and D- pins go up to 2.8V you couldn't use one of the options as it only goes to 2.5V. The variable voltage one is probably ok, though.

0 Fredrik K over 12 years ago in reply to Jose C

TI__Guru** 106705 points

Also, efficiency is not really that important when powered from a USB connector.

/Fredrik

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CC2540 and step down converter for Li-ion battery