AnsweredAssumed Answered

I'm having a problem with the ADA4899 Disable function.

Question asked by JohnMac on Sep 13, 2012
Latest reply on Sep 14, 2012 by charlyelkhoury

I'm using the ADA4899-1 in the CP-8-2 package.  When the DISABLE input is floated what does the output, pin 7, of the amplifier do?

I have a circuit with two amplifiers and want to mux them together.  The inputs to each amp are opposite polarity and I want to use the DISABLE to select the proper polarity for followup circuits.  The circuit runs off +/- 5 volts and each amplifier is configured as a unity gain buffer (pin 2 connected to pin 3).   Each amp by itself works fine when enabled.  When an amplifier is disabled (DISABLE input brought to ground) the outputs don't TRI-State as I thought they should.  Anyway when I connect the outputs of the two amps together the disabled amp is messing with the enabled amp.  Should I use a 10K feed back resistor rather then a short between pins 2 and 7?

 

Thanks

John

Outcomes