OPA859-Q1: OPA 859 TIA BW issue

HARI T O1

Expert 1675 points

Part Number: OPA859-Q1
Other Parts Discussed in Thread: OPA859

Tool/software:

Dear Team,

I am designing a TIA using OPA859 the output of the TIA is connected to a comparator.I need a BW of nearly 300Khz.

When I connect the open loop comparator at the output of TIA I am getting the required BW.Please see the image Below.

But for the same circuit when I connect a comparator with hysteresis my Bandwidth is reduced drastically.Plase see the image below.

I am attaching both the circuits along with this.May I know why it is happening like that.

Regards

HARI

0 Anant Sinha 5 months ago

Hi Hari,

I tried running the AC response of both the Tina circuits which you shared and I am getting the same 3dB bandwidth of around 800K in both the cases.

Circuit Without Hysterisis:-

Circuit with Hysterisis:-

Regards

Anant

0 HARI T O1 5 months ago in reply to Anant Sinha

Expert 1675 points

Hi Anant,

Thank you .

Now I am also getting the same response.

May be some tool issue

Regards

HARI

+1 Anant Sinha 5 months ago in reply to HARI T O1

Hi Hari,

No worries, I am closing this tread for now, let me know if you face any other issue.

Regards

Anant

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