Current sensing interface based on noise-shaped pulse width modulation

This paper presents noise-shaped pulse width modulation scheme for accurate current sensing. The continuous-time comparator in the conventional period modulation current sensing interface is replaced with a clocked dynamic comparator to reduce the average power consumption. The integrator output voltage at the toggling point is sampled and delayed by one modulation cycle and applied to the auxiliary input of the dynamic comparator. Such a scheme produces a noise-shaped pulse-width-modulation output and is simple to implement. A prototype design is simulated and verified based on a 0.13μm CMOS technology.