Replacement for this part?

Hello deltapapa,

You can check ADA4896-2 and ADA4899-1 respectively and see if they fit with your application.

Best regards,
Paul

I bought the ADA4899-1 and I discovered that the ADA4899-1 is not a rail to rail amplifier like the LTC6228.   

Usually when a part is at the end of life, another part is planned to replace that part.     Is it possible to find another part to replace the LTC6228 that is a rail to rail amplifier with better bandwidth specs?

Hello CircuitDeveloper,

Apologies for the delayed response. To furthermore help you with this, here are some follow up questions:

1. What will be your end or target application?

2. What are your target specifications? (target supply voltage, input voltage, output voltage, circuit configuration and gain, bandwidth, slew rate, etc.) 

Having these data will surely help us find a suitable part for you. Thanks!

Best regards,
Paul

Dear Paul,

       Thank you for your reply.   To be clear my goal was to find a replacement for the LTC6228 in an S8 package.  

       The LTC6228 was advertised to be "unity gain stable".    However, I did not find the LTC6228 to be unity gain stable when I created a test circuit design - PCB parasitics resulted in instability.     

        My application was to find the highest frequency, general purpose, rail to rail op amp in an S8 package that is stable at unity gain.   

        In terms of my priorities, I find stability ("unity gain stability") to be my highest priority so that I can used the op amp for general purpose applications.   The next priority is frequency bandwidth. 

        The maximum signal input voltage for my application is ~4VDC on both input ports.    By the way, I come across the term "maximum input differential voltage" can you please explain with a test circuit and input voltage signals applied - what constitutes exceeding the "maximum differential input voltage."   I have read a lot of data sheets from other companies and, sometimes, the way those values are expressed is moot. 

        Can you please find me an analog devices replacement part that is suitable for "general purpose" applications - a reasonable input capacitance parameter to meet to avoid instability?  

        Also, I would appreciate any information in your experience with the ADI op amps that insures stability (such as a potential grounding requirement on the IC that must be met when soldering the op amp to my PCB).    This type of information is usually IC specific.   Again, my goal, first, is "stability" then high bandwidth applications.  The supply voltage would be +5V and -5V.    If you require a sample general purpose application consider a typical "subtractor" configuration.   Aside note:   I find that subtractor circuits operate better with 2 voltage supplies in circuit, therefore, dual supply op amps would be preferred.

        I would like to thank you for your past reply and I look forward to reading your next reply.

Dear Paul;

        A few weeks ago I replied to your questions.    I am awaiting a reply from you about any op amp that can fulfill my needs.

        I should have been more careful about how I expressed my opinion about the LTC6228 and the ADA4899-1 so that you do not get in trouble with ADI "management" if you reply to my questions.    My experimental boards did not take into account "parasitics" and in both cases I used "through hole" parts that are associated with high parasitics.     I did not realize how "sensitive" these parts are to a high "parasitic" environment.     Everyone knows that ADI makes the fastest op amps on the market and this "sensitivity" will most likely be found in every "fast" op amp sold by your competitors in the market today.  

        I am just looking for a reliable "go to" part that you know of that can "reliably" perform in general use applications.    You can "relax" all the requirements that I had set forth in my past posts.   

       I look forward to reading your reply and can you answer my question about "maximum" differential voltage and let me know of a "simple to understand" circumstance where  "maximum input differential voltage" will blow my part?

       Again, I would like to thank you for your consideration.    

Hello CircuitDeveloper,

I apologize if I have missed your reply, as we are currently supporting a lot of open queries. If you are looking for a general-purpose op amp that is unity gain stable, rail-to-rail, and has a wide supply voltage range, you can try checking ADA4099-1. You can also check our latest general-purpose op amp - ADA4510-2, and see if it will fit with your application.

In terms of the maximum differential voltage spec, you can check the following articles: 
MT-041: Op Amp Input and Output Common-Mode and Differential Voltage Range (analog.com) 
Data Sheet Intricacies— Absolute Maximum Ratings and Thermal Resistances | Analog Devices

One more thing, you can try simulating first your circuit/application first on LTspice to make sure that your circuit is properly working before proceeding with the actual setup.

Regards,
Paul

Hi all, I have found also AD8045 with similar characteristics of LTC6228. Still output range is lower, as for the other suggested alternates. Any comments on AD8045?

Hello fgiusti,

Looking at the overall specs of LTC6228 and AD8045, there are other parts which are closer to the specs of LTC6228. But yes, you can also use AD8045 depending on your application.


Regards,
Paul