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AOP

Category: Hardware
Product Number: LT6233
Software Version: No

Hello,

I would like to find a equivalent with this component 'LT6233CS6#TRMPBF' because i have to order 5000 pieces. Do you know any components with the same footprint and the same function pins because I have already designed the PCB.

Thank for your helps

Regards

  • Hi,

    Thank you for your helps (I had not seen this bias current). In fact my signal from the hydrophone ( is about 1µV to 300µV). And after your simulation that I modified to have 1µV at the input :

    I think it is impossible to satisfy the maximum variation and the minimum variation. In fact I don't know if I must amplify the signal before before attacking the high pass filter. But what is the minimum voltage level that AOP LT6233 can accept ?

    I think, the better solution is to have a component with with adjustable offset and very low bias current. I don't know if it exists.

    You add a dummy current source : -1.5µA 

         

    But how do we do it electronically ? Is there a dedicated component for this or a specific assembly ?

    But now, I see the problem more clearly thanks to your advice.

    Regards


     

       

  • Hi Hooman,

    Sorry to bother you but I'm still looking for a -1.5µA current source and haven't found it yet.

    Thank for your helps

    Regards

  • 0
    •  Analog Employees 
    •  Super User 
    in reply to 206_RC

    Hi ,

    Sorry to bother you but I'm still looking for a -1.5µA current source and haven't found it yet.

    Response: The -1.5uA current source I added was only there to demonstrate that the input bias current of LT6233 (about 1.5uA in its model) is responsible for your output offset. Once I added the -1.5uA current source, I was able to null the output offset. So, that's why I recommended choosing a device with CMOS / JFET inputs where the input current is in the pA or nA range (much lower) so that you won't have this offset.

    Regards,

    Hooman

  • I recommended choosing a device with CMOS / JFET inputs where the input current is in the pA or nA range

    Probably at the inputs of AOP, but how can I know if the inputs are CMOS/JFET ? In the datasheet ?

    After searching I found these selections :
    www.analog.com/.../11080

    There are 2 components that correspond to my selection : AD8233/AD8428

    The AD8233 with 'CHIPS OR DIE,20-Ball WLCSP (2.04mm x 1.705mm)' What is this box ? I just need boxes of types SOT-23 or equivalent.

    And for the second AD8428, you advised me in another Topic which I am trying to understand for the moment. 

    Thanks you for your helps

    Regard

  • 0
    •  Analog Employees 
    •  Super User 
    in reply to 206_RC

    Hi ,

    If you're looking for Instrumentation Amplifiers with low input bias current, you can look at this list sorted for the lowest noise voltage on-top, and input bias current < 400pA:

    www.analog.com/.../11080

    AD8233 that you mentioned is offered in WLCSP packaging or die only (not in SOT23). The closest packages to the SOT23 that you want which I can find is in 8-pin MSOP are:

    LT6370

    AD8220

    AD8428 is only offered in the 8-pin SOIC package.

    Regards,

    Hooman

  • AD8428 is only offered in the 8-pin SOIC package.

    Hi Hooman,

    For this package there is no problem for the manufacture and also MSOP. Sorry I don't know all package for cms components.  
    I'll see the LT 6370 and AD8220 and I will do the simulation with these components. Just one precision I use this AOP only for High pass filter not for Amplifier (or 1) 

    Thank you