I'm currently using a demo-board from sparkfun for quick prototyping of a hall-effect sensor application. The specific chip I'm using is the ACS723-5AB, a Hall-Effect sensor that can measure between -5A and +5A.
Now that I'm done using the demo-board from sparkfun I'm looking to just directly use the sensor chip in my final circuit design.
One of the improvements I wanted to make was to add a low-pass filter on the sensor output for smoothing the signal a bit by adding a simple RC filter, but when I look at the circuit-design of the SparkFun board, they don't use an RC filter but just a capacitor to ground on the output line.
I can't imagine anything drawing current from the sensor output, so decoupling doesn't seem likely. It doesn't really create a filter without a resistor (as far as I know?)
My question is: What is the purpose of capacitor C2 on Viout?