# Boosting the Analogue Response of a Sensor

I have a A1308KUATN-9-T Hall Effect sensor with the following sensitivity (from the data sheet):

As you can see, the sensitivity comes to about 9mV per Gauss on average.

My calculations (see below if you think this sounds wrong) come out to a flux density of 1.36 Gauss when I'm 3 inches above the magnet.

So that means I can expect a reading of 12.6 mV on my sensor's output... My goal here is to try to boost this to something closer to say 3V or so. Using an op-amp is the direction I'm assuming I should be taking, but if there's a better way I'm open to that.

Additionally, I'm really worried about noise affecting this. In other applications I'd say noise on a signal of +/- 10mV is fine but here it'd be terrible. If I put a decoupling capacitor on the 5v rail going to the hall effect, would that help clean up my noise? Should I do something between my sensor's output and op-amp's input?

So finally, to summarise: I'm expecting a ~12mV analogue response from a sensor that general outputs 0-5V. So I'd like to boost it the best I can and filter out any noise that could give a false reading (since the expected signal is so low to begin with).

For those interested,

Explanation for Flux density calculation:

The cylinder magnet I'm trying to detect will be approximately 3 inches below my sensor and given a diameter of 12mm and a height of 2.6mm with the assumption the residual magnetism of my magnet will be ~1.3 T.

• What kind of measurement are you taking? Is it DC or a time-varying signal? Commented Feb 7, 2019 at 22:16