THS3491: THS3491 unity gain bandwidth

Mahsa barkabian

Part Number: THS3491

Dear TI team,
Could you please let me know about the unity gain bandwidth or gain bandwidth product of the THS3491 opamp?
Unfortunately, I could not find anything in the datasheet. the bandwidth is just mentioned under the special circumstances, not in the open loop condition.

4 months ago

0 Alec Saebeler 4 months ago

TI__Genius 13010 points

Hello Mahsa,

The THS3491 is not designed to be operated in unity-gain; if the device is operated in a gain of 1V/V, there is considerable overshoot on the output signal. This is discussed in related threads: https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/1310018/ths3491-unity-gain-and-transformation-isolation-in-cascade

https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/735365/ths3491-minimum-gain-of-ths3491

If you provide the application or target gain or bandwidth for your circuit, we can help simulate and examine how the THS3491 can work best in your solution.

Best,
Alec

0 Mahsa barkabian 4 months ago in reply to Alec Saebeler

Prodigy 50 points

Hi Alec,
Thanks for your response.
My target gain is around 8dB with a bandwidth of 500MHz.
Regards,
Mahsa

0 Nick Nauman 4 months ago in reply to Mahsa barkabian

TI__Expert 6050 points

Hi Mahsa,

We will work on putting together a simulation that shows your target requirements using the THS3491.

Thanks,

Nick

0 Nick Nauman 4 months ago in reply to Nick Nauman

TI__Expert 6050 points

Hi Mahsa,

The models we offer for the THS3491 in DDA and RGT packages have the limitations of aligning with the datasheet for +/-15V supply operation in a gain of 5V/V for bandwidth specifications as mentioned in the model of the device.

However, you can see that in a gain of 2V/V the -3dB frequency is still above 700MHz. A gain of 8dB is slightly above a gain of 2V/V but the bandwidth will not vary significantly form 6dB to 8dB of gain. 500MHz bandwidth with a target gain of 8dB is attainable with the THS3491.

Thanks,

Nick

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THS3491: THS3491 unity gain bandwidth