TPS5420: Constant current output via sense current feedback

Cameron Straatsma

Part Number: TPS5420
Other Parts Discussed in Thread: LM5117, TPS54240

Is it possible to get stable operation of the TPS5420 buck converter by measuring the output current via a sense resistor and MAX4372H current sense amplifier (for example), and feeding the output voltage to the VSENSE pin? What type of compensation network would be required to make this work? I've looked through the datasheet examples and the SLVA237C Application Report regarding stability with ceramic and aluminum output capacitors, but I am having some trouble translating this information for use with a current sense amplifier in the feedback loop.

over 5 years ago

0 Katelyn Wiggenhorn over 5 years ago

TI__Genius 11040 points

Hello,

I would expect this to be possible. I will check with the product expert to see if we have any example designs using this configuration.

Best Regards,
Katelyn Wiggenhorn

0 Katelyn Wiggenhorn over 5 years ago in reply to Katelyn Wiggenhorn

TI__Genius 11040 points

Hello,

Please see the applications note which details designing a constant current output with the LM5117. www.ti.com/.../snva829.pdf

You can use this as a reference with the TPS54240.

Please let me know if you have any additional questions.

Best Regards,
Katelyn

0 Cameron Straatsma over 5 years ago in reply to Katelyn Wiggenhorn

Prodigy 20 points

Actually, I am looking to implement this with the TPS5420, not the TPS54240. Is possible to properly compensate the feedback path in the TPS5420 when using a current sense amplifier?

0 Katelyn Wiggenhorn over 5 years ago in reply to Cameron Straatsma

TI__Genius 11040 points

Hello,

Thank you for pointing this out. It will be possible to compensate the TPS5420 similar to the methodology for the TPS54240.

Please let me know if you have any additional questions.

Best Regards,
Katelyn

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TPS5420: Constant current output via sense current feedback