LMP7721: LMP7721 Guard RING's problem points:

allen wang17

Part Number: LMP7721

LMP7721 Guard RING's problem points:

The Faraday GUARD RING of LMP7721, namely GUARD RING, the middle input line, we understand is connected to LMP7721, but, is the outer metal RING connected to the ground?

How to implement the Guard RING in Layout?In headroom or what?

over 5 years ago

0 Dennis Goeke over 5 years ago

TI__Genius 11135 points

Allen

The Guard ring is not connected to ground; it is a separate conductor. It is driven by buffer amplifier U2 on the EVM. The idea is to drive the guard at the same potential as the input signal to reduce/eliminate leakage between the input and other areas of the circuit.
There is a very good description in section 4.2.2 in the EVM users guide:
www.ti.com/.../snou004.pdf

Regards
Dennis

0 allen wang17 over 5 years ago in reply to Dennis Goeke

Intellectual 430 points

hi Dennis Goeke:

Thank you very much for solving my problem

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LMP7721: LMP7721 Guard RING's problem points: