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    SOT23-5 Component with Code starting with UU - Trying to identify the component

    Hello,

    I am working on doing some reverse engineering on a circuit that uses a piezo element to 'sense' virbrations on a musical instrument and then computes whether the vibration matches the frequency of a predetermined pitch frequency.
    I figured out most of the components on the base plate except for the SOT23-5 component in the circuit. I have about four different base plates to look at and, on each one, the SMD SOT23-5 component has four characters and each code starts with UU. I'm guessing the remaining two characters, different on all four examples, must be some sort of date code.
    Here's a photo of the on board components and a sketch of the schematic from my dissection of the circuit.

    Click image for larger version. 

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    Click image for larger version. 

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    This is my understanding of what is most likely going on in the circuit:
    The positive from the piezo element 'enters' the circuit from the left. The raw signal is 'tapped' at point I10 and sent to the processor board and then goes into the SMD component that I'm trying to identify. There appears to be a 'tap' of an output signal at E10 that also gets sent to the processor board.

    Thanks for the assistance.

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  2. #2
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    Re: SOT23-5 Component with Code starting with UU - Trying to identify the component

    It is probably a Microchip MCP6L91 opamp.

    http://ww1.microchip.com/downloads/e...Doc/22141b.pdf

    Edit:
    I10 is connected to pin 1, which is the output of the opamp (the amplified input signal).
    The input signal goes to pin 4 (which is the "virtual ground" negative input of the opamp).
    E10 is the supply voltage.


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    Re: SOT23-5 Component with Code starting with UU - Trying to identify the component

    Thanks a bunch. I will explore the Microchip MCP6L91 opamp.



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    Re: SOT23-5 Component with Code starting with UU - Trying to identify the component

    For anyone else who may stumble upon this thread. Here is a more refined drawing of the circuit. Upon researching op-amps, it appears this is a differential (not differentiating) op amp circuit with an AC integrator and DC Gain Control. Thanks again for the assistance @std_match

    Click image for larger version. 

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