• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 48 subscribers
  • Views 461 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

single 5v supply amplifier selection

Calum Mackinnon
Genius 4155 points

Other Parts Discussed in Thread: INA282

Do you know of a good differential or instrumentation amplifier with the following qualities?
  • Supply Voltage single ended 5V (could go 12V and just current limit the output to the A/D  if we can't go over Vcc with the input CM voltage)
  • SMT package
  • Low input / output offset.  Ideally below 1mV.
  • rail to rail output
  • gain of 1 (negotiable depending on availability)
  • Able to handle differential measurements that can go several volts below or above Vcc- / Vcc+ (Ideally 5Volts below ground)
I am making a circuit that measures battery voltage at the battery terminals instead of inside the charge controller.  I am bringing in a voltage divider from the battery and placing it across this amplifier.  Our internal ground to the charge controller is referenced to battery minus.  We don't have any negative supplies inside the product and don't want to add any at this time.
 
There are two things that can / will bring the voltage across the input of the amplifier below local ground.  One is if the customer wires the remote battery sense backwards.  The other which is always true... when there is high current a voltage drop occurs across the wires and connections.
  • 0
    TI__Mastermind 25865 points

    Hello Calum,

    Perhaps you'd be interested in our INA282 (current-shunt monitor).  This device utilizes a single supply and can amplify a differential input signal with a common-mode voltage below ground.  One possible issue is that the output is not quite rail-to-rail.  The output can swing from GND+40mV to (V+)-0.4V.  Additionally, the requirement for G=1 may be an issue.  Perhaps you could divide down the input voltage to accomodate the gain.  Concerning reverse battery connection, you could look into either using a series diode or FET as discussed in the application report SLVA139.

    I hope this helps!