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ADA4870 - Floating state and Temperature pin

Question asked by Martin90 on Nov 13, 2015
Latest reply on Nov 24, 2015 by iamPhil


I am student from germany and I have to do a projekt.

I want to realize it with your amplifier ADA4870.

I have some questions to you about this device:

  1. How can I realize the floating-state of the ON-pin? Is there a special IC for that job?
    I would it do with two optocouplers which can switch between -18V for LOW and -14.7V HIGH state or float if booth are off.

  2. How can I measure the output-voltage of the TFL-pin?
    I want measure it with an operational amplifier.
    I saw that the output voltage sink down if I connect it with a voltage divider of about 12kOhm. I change the value to 1MOhm. Now it is OK. But how much current can give the TFL-pin?
  3. Is there an application note where I can find these information or circuits?


I am looking forward to hearing from you soon.

Thank you for any help!!