Low Power DC/DC converter

Tanzim Kawnine68

Other Parts Discussed in Thread: TPS61093, TPS61040, TPS62125, TPS54040, TPS65130, INA163, LM2662

Hi

For an accelerometer project, a very low power DC-DC boost converter (Vin= 5V, Vout = +8V and -8V) is required. In the following I will attach a list which is the technical requirement.
Now, my problem is where can I find such low power DC-DC converter or at least close to it?
Grateful for the replies.

Best,
TK

over 10 years ago

0 Chris Glaser over 10 years ago

TI__Guru**** 150900 points

It's unclear how much current you need on each rail. Could you kindly restate this?

The TPS62125 is probably the best solution for a 5V to -8V inverter. The TPS61093 or TPS61040 might be good 5V to 8V options.

0 JohnTucker over 10 years ago

TI__Guru**** 191445 points

You could possibly consider TPS54040. It can be configured as a dual output supply. See this app note:
www.ti.com/.../slva369a.pdf
It is applicable to lower power devices such as TPS54040 as well.

0 Jasper Li over 10 years ago

TI__Mastermind 46905 points

not sure if you have high requirement for the -8V voltage accuracy. you may find a 5V to 8V boost converter and have a phantom circuit to generate the -8V. please refer tps61040 datasheet page 16, Figure 18 "positive and negative voltage output circuit"

thanks
Jasper Li

0 Brigitte over 10 years ago

TI__Guru 65470 points

Hello Tanzim,

Converters generating one positive and one negative rail can be found in the split rail topic here:

Split Rail Converter

For your requirements, TPS65130 would most probable be the best choice.

Best regards,
Brigitte

0 Tanzim Kawnine68 over 10 years ago in reply to Chris Glaser

Prodigy 130 points

The dual output power supply will supply voltage to an one axis accelerometer and an instrumentation amplifier (ina163 is chosen) will amplifiy the signal further to an ADC, I figured max 100mA should be enough all together, i.e. 50mA on each rail. Any other suggestions?

0 JohnTucker over 10 years ago in reply to Tanzim Kawnine68

TI__Guru**** 191445 points

You could take a look at some of the suggestions already made. Let us know if you have questions about them.

0 Tanzim Kawnine68 over 10 years ago in reply to Jasper Li

Prodigy 130 points

This seems to be a very good schematics except the output current should be a bit higher (say around 80 to 100mA). I forgot to mention that one of the requirements is that there should be as few components as possible used on the board.
//TK

0 Tanzim Kawnine68 over 10 years ago

Prodigy 130 points

Since one of the requirements is to have as few components as possible for on the board, there is one voltage regulator which I thought could be suitable for this task, i.e. LM2662. It seems to be rather simple circuit . Please check Figure 19 and Figure 27 in the datasheet.
www.ti.com/.../lm2662

Any suggestion? Anybody used this IC before?

//TK

0 JohnTucker over 10 years ago in reply to Tanzim Kawnine68

TI__Guru**** 191445 points

I don't think that will be a good solution for you. It wants to be a voltage doubler, so it would want to generate +/- 10 V

0 Tanzim Kawnine68 over 10 years ago in reply to JohnTucker

Prodigy 130 points

That's true. But this accelerometer which is being used for this project, seems to have an input voltage range between +/- 6V to +/-15V. Thats why I was thinking whether its a good idea to increase the output voltage to +/-10V and have less components on the board.

Power management

Power management forum

Low Power DC/DC converter