LP8758-B0: LP8758-B0 / Measure loop gain and phase margin

S.Satoshi

Part Number: LP8758-B0
Other Parts Discussed in Thread: TPS53319

Hi,

Now the customer consider to evaluate LP8758-B0 and they ask how to measure loop gain and phase margin by using EVM. So please let me know where the injection resistor should be added and also the measurement point on EVM.

Best Regards,

Satoshi / Japan Disty

over 8 years ago

0 Richard Solarski over 8 years ago

TI__Genius 10885 points

Satoshi-san,

Since the feedback is differentially measured from FB_B0 to FB_B1, I would expect the injection point to be across J0 once populated with a matched resistor.

Looping in the product expert to confirm.

Best Regards,
Rick S.

0 S.Satoshi over 8 years ago in reply to Richard Solarski

Guru 21685 points

Hi Rick,

Thank you for your comment. I'm waiting for the comment from product expert.

Best Regards,
Satoshi

0 Tomi Koskela over 8 years ago in reply to S.Satoshi

TI__Genius 11020 points

Hi Satoshi-san,

Yes you can replace the 0ohm feedback resistor with suitable resistor for injecting the measurement signal.

Thanks.

Best regards,

Tomi Koskela

0 S.Satoshi over 8 years ago in reply to Tomi Koskela

Guru 21685 points

Hi Tomi,

Thank you for your comment. Let me ask more about the case of 4-Phase configuration. Which feedback line should we add injection resistor at 4-Phase configuration?

Best Regards,

Satoshi

0 S.Satoshi over 8 years ago in reply to S.Satoshi

Guru 21685 points

And also please let me know the connection of four wire of FRA for differential sensing. I know the basic connection for voltage divider configuration as attached that is referred from here.

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