TLVH431: Stability

Shota Mago

Expert 6820 points

Part Number: TLVH431
Other Parts Discussed in Thread: TL431, ATL431

Hi team,

The datasheet states "TI recommends to choose capacitors that will give a phase margin > 5° to guarantee stability of the TLVH431”
I think phase margin around 5° should be unstable or show large ringing. Is this just typo?
TL431/ATL431 have application notes(SLVA685/SLVA482A) which explain effect of adding series resistor to output capacitance in order to improve phase margin.
Do you have similar data(figure 6~8 of SLVA685) for THVH431?

Best regards,

Shota Mago

over 1 year ago

0 Andrew Li over 1 year ago

TI__Prodigy 500 points

Hi Shota,

I am currently looking into this issue and will give you an update this Thursday PDT.

Best Regards,

Andrew Li

0 Andrew Li over 1 year ago

TI__Prodigy 500 points

Hi Shota,

1. A phase margin of 5 degrees will have some ringing at startup, but it will settle over time. A phase margin >35 degrees will be super stable, and there will not be any underdamping or ringing.

2. I am still looking to see if we have the equivalent figures for the TLVH431, and I will give you an update as soon as possible.

Please let me know if you have any further questions!

Best Regards,

Andrew Li

0 Shota Mago over 1 year ago in reply to Andrew Li

TI__Expert 6820 points

HI Andrew,

Thanks for your support. I understood for question#1.

Best regards,

Shota Mago

0 Andrew Li over 1 year ago in reply to Shota Mago

TI__Prodigy 500 points

Hi Shota,

Thank you for your patience! I am still looking into the figures and will give you an update as soon as possible.

Best Regards,

Andrew Li

0 Andrew Li over 1 year ago in reply to Andrew Li

TI__Prodigy 500 points

Hi Shota,

I have already asked for support from our design team, and I am still waiting for a response. I am aiming to get an update by Thursday. Thank you again for your patience!

Best Regards,
Andrew Li

+1 Andrew Li over 1 year ago in reply to Andrew Li

TI__Prodigy 500 points

Hi Shota,

I just heard back from our design team. There is no stability condition with ESR for the TLVH431.

Best Regards,

Andrew Li

0 Shota Mago over 1 year ago in reply to Andrew Li

TI__Expert 6820 points

Hi Andrew,

Thanks for confirmation with design team.

Best regards,

Shota Mago

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TLVH431: Stability