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LM3447 additional parameters

Sergey Markov
Intellectual 510 points
Other Parts Discussed in Thread: LM3447

I need to know two parameters of LM3447, not described in the datasheet:

1) What current can source FLT1 pin w/o significant internal voltage drop (i.e. max 0.2V), and w/o significant impact on overall performance of IC  ?

2) What input offset current sinks (or sources) FLT2 input (or what maximum resistance can have it's driver)

  • 0
    TI__Mastermind 28655 points

    Hello,

    Here is what I found out for your questions:


    The limitation on FLT1 source and sink current is an internal 500 ohm resistance to the pin, the drivers are in the 20-25 ohm range so the 500 ohms dominates.

    FLT2 pin is an input to an voltage to current converter circuit.  Therefore, the input impedance is in the range of 10 Mohm.  There is no additional current source/sink attached to FLT2 pin.

  • 0 in reply to Irwin Nederbragt
    Intellectual 510 points

    Thank you.

    About FLT2 input I said about parasitic currents, as offset current of inputs of operating amplifiers, but not about additional current sources. Resistance of 10 MOhm means offset currents in the range of 0.01...0.1 uA?