Design of an integrated sampling and conversion system for energy meters

This paper shows the design and post-layout simulation of an integrated analog-to-digital interface for energy quality meter systems, in which voltages and currents are sampled and converted to digital values for later digital processing by a fully integrated system or discrete DSP. It has been used the switched capacitor technique on the sampling and conversion circuits, instead of the analog conventional techniques, thus reducing the circuit size and achieving a higher precision. The proposed analog front-end was successfully simulated in a 0.35um CMOS process from AMS. The system has six input channels and can reach 10 bits of resolution at a sampling rate of 369,000 words per second. The circuit takes an area of 5.2 mm2, including pads.