WEBENCH® Tools/TPS61088: Can the output voltage of tps61088 be changed by using DAC to control FB.

user6266014

Part Number: TPS61088

Tool/software: WEBENCH® Design Tools

Can the output voltage of tps61088 be changed by using DAC to control FB.The following is the schematic diagram I designed. I want to control the output voltage of tps61088 from 0V to 12V through the DAC output of single chip microcomputer. Help me to see the schematic diagram which needs to be modified to realize the output voltage adjustable from 0V to 12V, thank you!

over 5 years ago

0 Helen chen over 5 years ago

TI__Mastermind 40080 points

Dear Sir,

The concept and the sch is OK. But the output voltage can only change from V+ to 12V. Because the internal upside FET has a body diode connects the Vout with the Vin.

Please change the compensation network to R85=15k, C51=4.7nF for better stability.

0 user6266014 over 5 years ago in reply to Helen chen

Prodigy 65 points

in e2echina forum The engineer told me that the adjustable range is VFB ~ 12V. If you want to start from 0V, you need to add operation amplifier.If I want to export from 0V, is there another solution?

0 Helen chen over 5 years ago in reply to user6266014

TI__Mastermind 40080 points

Hi Sir,

The E2E China make a mistake. Vomin is clamped by the Vin. This is a boost converter, you can't get 0V. You need to use a buck-boost converter to realize the concept. But the Vin_min still only around 1V.

Could you please share the application with us , why need 0V?

0 user6266014 over 5 years ago in reply to Helen chen

Prodigy 65 points

My application is to input 2.7V ~ 4.2V and output 0v~12V / 1.5A ~ 2A. I can control the output of voltage through single chip microcomputer ，I wang make a numerical control adjustable power supply. The package of the chip should be as small as possible, similar to tps61088.Is there any other recommended scheme?