A neuron circuit is capable of producing a weighted sum of digitized input signals and applying an activation function to the weighted sum so as to produce a digitized activation signal as output. The circuit includes at least: one multiplier multiplying each input signal (x1 to xn) with a weight value (w1j to wnj), one accumulator accumulating the results of the multiplier so as to produce the weighted sum, and one activation unit executing the activation function. The activation unit comprises at least one shift unit and at least one saturation unit capable of approximating a non-linear activation function. The result of the approximated activation function is obtained by one or more arithmetic shifts applied to the weighted sum.