The only analog circuitry used in the AD71056 is in the - ADCs and reference circuit. All other signal processing, such as multiplication and filtering, is carried out in the digital domain. This approach provides superior stability and accuracy over time and in extreme environmental conditions. The AD71056 supplies average real power information on F1 and F2, the low frequency outputs. These outputs either directly drive an electromechanical counter or interface with an MCU. The high frequency CF logic output, ideal for calibration purposes, provides instantaneous real power information. The AD71056 includes a power supply monitoring circuit on the VDD supply pin. The AD71056 remains inactive until the supply voltage on VDD reaches approximately 4 V. If the supply falls below 4 V, the AD71056 also remains inactive and the F1, F2, and CF outputs are in their nonactive modes.