TIDA-01350: TIA gain and BW calculations

Barrett Bryan

Part Number: TIDA-01350
Other Parts Discussed in Thread: LMH5401

How was the gain and bandwidth calculated for this reference design using LMH5401? I'd like to better understand this so I can reduce bandwidth for my application.

over 5 years ago

0 Hasan Babiker31 over 5 years ago

TI__Genius 15605 points

Hello Barret,

In regards to the overall transimpedance gain, section 5.3 of the reference design discusses this. The simplified equation is Transimpedance gain = RF1 × (RF2 / RG2) / 2, however there is some adjustments that need to be made due to the internal resistance of the LMH5401.

In regards to bandwidth, you take a look at this app note here which discusses this concept in regards to single-ended TIAs. However the same concepts apply to an FDA as well:

https://e2e.ti.com/blogs_/b/analogwire/archive/2016/05/06/what-you-need-to-know-about-transimpedance-amplifiers-part-1

Please let me know if you have any questions

Best,

Hasan Babiker

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TIDA-01350: TIA gain and BW calculations