The IR3721 is a versatile power or current monitor IC for low-voltage DC-DC converters. The IR3721 monitors the inductor current in buck or multiphase converters using either a current sensing resistor or the inductor's winding resistance (DCR). The output (DI) is a pulse code modulated signal whose duty ratio is proportional to the inductor current. An analog voltage that is proportional to power is realized by connecting VK to VO and connecting an RC filter to DI. The IR3721 uses Patent Pending TruePowerTM technology to accurately capture highly dynamic power waveforms typical of microprocessor loads.