The NCP81245 is a 3 rail Multi-Phase buck solution is optimized for Intel IMVP8 compatible CPUs with user configurations of 3/2/1 + 3/2/1 + 1 phases, including an option to do 4/3/2/1 + 2/1 + 1. The controller combines true differential voltage sensing, inductor DCR current sensing, input voltage feed-forward, and adaptive voltage positioning to provide accurate regulated power for Notebook applications. The multiphase-rails’ control system is based on Dual-Edge pulse-width modulation (PWM) combined with DCR current sensing providing the fastest initial response to dynamic load events at reduced system cost. The single-phase controller can be used for SA or GTUS rails. It makes use of ON Semiconductor’s patented high performance RPM operation. RPM control maximizes transient response while allowing for smooth transitions between discontinuous frequency scaling operation and continuous mode full power operation. The single-phase rails have an ultra low offset current monitor amplifier with programmable offset compensation for ultra high accuracy current monitoring.