TPS54531: Control the tps54531 with a MCU

Youssef Nassar

Part Number: TPS54531
I tried to control the output voltage wit an an analog signal from a mcu it changed it actually but when i apply a load that withdraw more current the voltage drops so i was asking if it is possible to do that or if there is any other type of regulator that i can control it digitally from a mcu but that can supply 24V and around 5A

over 5 years ago

0 Shawn Nie over 5 years ago

TI__Genius 10070 points

Hi,

Could you please share the schematic and waveform?

Shawn

0 Youssef Nassar over 5 years ago in reply to Shawn Nie

Prodigy 70 points

This is the schematic but unfortunately I don't have a waveform for the output.

0 Shawn Nie over 5 years ago in reply to Youssef Nassar

TI__Genius 10070 points

Hi,

What is the output voltage range which you want to adjust? And what is the output voltage when you add the load? what is the value it drops to?

Shawn

0 Youssef Nassar over 5 years ago in reply to Shawn Nie

Prodigy 70 points

Hi,

The output voltage range I want to adjust is from 0 to 24V , the output voltage when I add the load keeps falling until it reaches 0V.

0 Shawn Nie over 5 years ago in reply to Youssef Nassar

TI__Genius 10070 points

Hi,

The input voltage is 24V, and this converter can't support 100% duty cycle, 24V output voltage is impossible.

If you adjust the output voltage to 5V or 12V, and then add the load, does it still has this issue?

Shawn

0 Youssef Nassar over 5 years ago in reply to Shawn Nie

Prodigy 70 points

Hi,

Yes I know that I need to supply more than 24V to get the 24V at output.But when I adjust the duty cycle of the GPIO14 to get the 5V output it still have the same issue.

0 Shawn Nie over 5 years ago in reply to Youssef Nassar

TI__Genius 10070 points

Hi,

The schematic looks fine. Please share the layout, let's review it.

And you can try to remove the MCU signal, keep the default output, and then check if there still have the same issue.

Shawn

0 Youssef Nassar over 5 years ago in reply to Shawn Nie

Prodigy 70 points

Hi,

Unfortunately the layout isn't in my possession right now,but if there is any tips for it that would be great.

Also I have tried to remove the MCU signal and the output was stable even with the load.

0 Ryan Hu (BSR-MV) over 5 years ago in reply to Youssef Nassar

TI__Expert 4035 points

Hi Youssef,

Since you have confirmed the device works well after removed the MCU signal, could you please try with a mirror change to the RC filter at the FB pin?

slyt777_Methods of output-voltage adjustment for dcdc converters.pdf

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TPS54531: Control the tps54531 with a MCU