Low power WTA circuit for optical position detector

A time domain winner take all (WTA) circuit for a 1D optical position detector is presented. The circuit implements a new asynchronous technique which estimates the position of a light spot impinging on the sensor with sub-pixel resolution. This technique first detects the peak of the light spot, then, starts a new competition, by eliminating the winner pixel. In this way the sensor asynchronously dispatches the pixels in order to reconstruct the spot profile. The simulated circuit shows a total power consumption of about 15.6 muW at 3.3 V, while the average dynamic power consumption needed to implement one step of the algorithm, can be estimated to be about 0.4 nW