Voltage regulation

[elki]

Question: I would like to make a digitally controlled 10V supply, starting from 5V from Arduino. If I were not to increase the voltage to 10V, I would use an R-2R ladder, controlled by digital pins. Is there any better way than introducing a voltage step-up regulator for each digital pin when using an R-2R ladder approach?

[ggchab]

I would create a reference voltage with the R-2R ladder/digital pins and then use an op amp to obtain the right voltage.
I guess you don't need high currents ?

[elki]

Good idea!

I would create a reference voltage with the R-2R ladder/digital pins and then use an op amp to obtain the right voltage.
I guess you don't need high currents ?

[elki]

A follow up question: would the amplification stage work with a boost converter in case one should go to higher voltages (let's say 50V)? I am not sure how linear the response of the boost converter is in terms of output/input voltages.

I would create a reference voltage with the R-2R ladder/digital pins and then use an op amp to obtain the right voltage.
I guess you don't need high currents ?

[tooki]

A boost converter is not an amplifier. Its output voltage is regulated, and not a fixed multiple of the input voltage.

The way to make a digitally-controlled boost converter is to manipulate the voltage on the feedback pin.

Texas Instruments has a Java power supply design tool that includes a calculator specifically for how to design this: https://www.ti.com/tool/POWERSTAGE-DESIGNER

See page 18 of the user guide: https://www.ti.com/lit/ug/slvubb4b/slvubb4b.pdf

[elki]

Thank you very much!

A boost converter is not an amplifier. Its output voltage is regulated, and not a fixed multiple of the input voltage.

The way to make a digitally-controlled boost converter is to manipulate the voltage on the feedback pin.

Texas Instruments has a Java power supply design tool that includes a calculator specifically for how to design this: https://www.ti.com/tool/POWERSTAGE-DESIGNER

See page 18 of the user guide: https://www.ti.com/lit/ug/slvubb4b/slvubb4b.pdf

[elki]

Sorry again, trying to understand the circuit (in the screenshot below).

I have the output voltage of 50V in my case, which I would like to digitally control. What is Vref and Vout here? I initially thought Vref can be e.g. 5V and Vout is 50V, but it does not seem it applies like this.

Thank you very much!

A boost converter is not an amplifier. Its output voltage is regulated, and not a fixed multiple of the input voltage.

The way to make a digitally-controlled boost converter is to manipulate the voltage on the feedback pin.

Texas Instruments has a Java power supply design tool that includes a calculator specifically for how to design this: https://www.ti.com/tool/POWERSTAGE-DESIGNER

See page 18 of the user guide: https://www.ti.com/lit/ug/slvubb4b/slvubb4b.pdf

[elki]

Sorry, I get it now!

Sorry again, trying to understand the circuit (in the screenshot below).

I have the output voltage of 50V in my case, which I would like to digitally control. What is Vref and Vout here? I initially thought Vref can be e.g. 5V and Vout is 50V, but it does not seem it applies like this.

Thank you very much!

A boost converter is not an amplifier. Its output voltage is regulated, and not a fixed multiple of the input voltage.

The way to make a digitally-controlled boost converter is to manipulate the voltage on the feedback pin.

Texas Instruments has a Java power supply design tool that includes a calculator specifically for how to design this: https://www.ti.com/tool/POWERSTAGE-DESIGNER

See page 18 of the user guide: https://www.ti.com/lit/ug/slvubb4b/slvubb4b.pdf