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OPA2388: Can we used OPA2388 to replace AD8605?

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Replies: 4

Views: 83

Part Number: OPA2388

 Dear all:

     Can we used OPA2388 to replace AD8605?  or have more suitable part? thanks!

  • Hello, there is a parametric cross reference to answer these questions at this link, 

    http://www.ti.com/amplifier-circuit/op-amps/cross-reference.html

    Putting in the AD8065, gives this result, If you need the higher supply of the AD8065, that OPA2388 is not close, 

    1. You probably want a single channel version of the OPA2810 -might be enroute? 

    2. That 145MHz on the AD8065 is deceptive - gain of 1 with peaking, it is actually the same 70MHz GBP as the OPA2810. 

    Michael Steffes

  • Dear user3830479,

    The OPA2388 (zero-drift, zero-crossover, true RRIO precision op amp) is a good replacement for the competitor part you mention. It appears to me, however, that the competitor part is a single channel package so it may be worth looking at the single channel OPA388.

    If you are looking for ultra low offset then OPA388 is the best choice here. If you are looking for lower power and DC precision then OPA325 (low noise, zero-crossover precision op amp) would be the best option. See the specification comparison below:

    I hope that this helps answer your question.

    Best,

    Daniel

  • In reply to Daniel Terrazas:

    Hello Daniel and user, 

    Well the OPA388 OPA325 seem like a bit of a stretch to match the AD8065. Unlikely the current design chose that AD part and then operated at 5V supply (but maybe?). The OPA2810 was aimed at the dual of the AD8065 so it should be pretty close, except channel count. 

    Having built a parametric cross reference tool, this "can you match a part" question is surprisingly difficult. Usually you don't know the design details so you have to go by the myriad of datasheet parameters. Then, one approach is to go spec by spec with a closeness of fit scoring. Add all this up for your universe and rank in descending closeness of fit - very subjective obviously - that's what was done for the parametric tool I noted above -but just to illustrate some steps, 

    1. Most important fit parameter is # of channels, if the same, high positive score, if not negative score - not doing that above obviously. 

    2. Next most important is supply range. Assign a score for the min and max total and contribute to scoring

    3. Then usually speed and slew rate,

    etc etc.  

    With a schematic and performance targets, this is much easier - but still not easy. 

    Michael Steffes

  • In reply to Michael Steffes:

    Hi Michael,

    Thank you for your detailed response.  I noticed that the competitor you are looking at may not be the one which was originally posted. The competitor you mention is a much higher speed. Given the competitor from the original post, the OPA388 and OPA325 should be suitable alternatives. 

    I hope this helps!

    Best,

    Daniel