OPA388: follower cut-off frequency

Florent Bouchara

Part Number: OPA388

Hi,

I am using OPA388 in simulation and I am quite dispointed to notice that in follower configuration I obtain as low as 10kHz cut-off frequency.

Could you please tell me if this is excepted or if there might be a problem with my simualtion (I tried with TINA and LTspice, both gave me that same result) ?

Regards,

over 2 years ago

0 Michael Hartshorne over 2 years ago

TI__Genius 13665 points

Hi Florent,

The OPA388 is a 10 MHz part, a 10 kHz 3 dB frequency is not correct. We would need more information to see what might be going on, if you can post your sim. we can investigate.

Regards,
Mike

0 Florent Bouchara over 2 years ago in reply to Michael Hartshorne

Prodigy 20 points

Hi Mike,

Thank you for your answer. I forward you a screnshot of the simulation.

Regards,

Florent Bouchara

0 Michael Hartshorne over 2 years ago in reply to Florent Bouchara

TI__Genius 13665 points

Hi Florent,

Do you have any DC voltage set for VIN? The device will not work properly when the input is set to the exact same voltage as the negative supply rail because the output needs at least 150 mV to acheive the AOL spec.

Please check if you increase the DC voltage if the bandwidth goes up.

Regards,
Mike

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OPA388: follower cut-off frequency