LMV321-N-Q1: output impidance od LMV321Q1M5

RONY THOMAS1

Prodigy 70 points

Part Number: LMV321-N-Q1

Can i get the output impidance od LMV321Q1M5

over 4 years ago

0 Tim Claycomb over 4 years ago

TI__Genius 15410 points

Hi Rony,

The open loop output impedance of the device is provided in Figure 43 of the datasheet.

Thank you,

Tim Claycomb

0 RONY THOMAS1 over 4 years ago in reply to Tim Claycomb

Prodigy 70 points

Dear Tim,

Thank you for your replay.

I just wanted to know the closed loop impedance which is negligibly small for an opamp.

Should i get actual impedence by dividing open loop impedance with loop gain?

Regards,

Ronie

0 Tim Claycomb over 4 years ago in reply to RONY THOMAS1

TI__Genius 15410 points

Hi Rony,

The closed loop output impedance can be calculated by

Zo/(1+Aol*Beta)

where Zo is the open loop output impedance and Beta is the feedback factor. As you can see the closed loop output impedance is dependent on the open loop gain of the amplifier (Aol) and the closed loop gain.

Thank you,

Tim Claycomb

0 kai klaas69 over 4 years ago in reply to RONY THOMAS1

Guru 140200 points

Hi Ronie,

yes, nearly. But divide the open loop impedance by (1 + loop gain) instead of (loop gain). Of course, for high loop gains (for instance at low frequencies) there will not be much difference...

Kai

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LMV321-N-Q1: output impidance od LMV321Q1M5