The MCP3905/06 devices are energy-metering ICs designed to support the IEC 62053 International Metering Standard Specification. They supply a frequency output proportional to the average active (real) power, as well as a higher-frequency output proportional to the instantaneous power for meter calibration. They include two 16-bit, delta-sigma ADCs for a wide range of IB and IMAX currents and/or small shunt (< 200 Ohms) meter designs. It includes an ultra-low drift voltage reference with < 15 ppm/C through a specially designed band gap temperature curve for the minimum gradient across the industrial temperature range. A fixed-function DSP block is onchip for active (real) power calculation. Strong output drive for mechanical counters are on-chip to reduce field failures and mechanical counter sticking. A noload threshold block prevents any current creep measurements. A Power-On Reset (POR) block restricts meter performance during low-voltage situations. These accurate energy-metering ICs with high field reliability are available in the industry-standard pinout.