The NCP81140 Multi−Phase buck solution is optimized for

Intel® VR12.5 compatible CPUs with user configurations of 4/3/2/1

phases. The controller combines true differential voltage sensing,

differential inductor DCR current sensing, input voltage

feed−forward, and adaptive voltage positioning to provide accurately

regulated power for both Desktop and Notebook applications. The

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. It has

the capability to shed to single phase during light load operation and

can auto frequency scale in light load conditions while maintaining

excellent transient performance.

High performance operational error amplifiers are provided to

simplify compensation of the system. Patented Dynamic Reference

Injection further simplifies loop compensation by eliminating the need

to compromise between closed−loop transient response and Dynamic

VID performance. Patented Total Current Summing provides highly

accurate digital current monitoring.

Features

• Meets Intel® VR12.5 Specifications

• Current Mode Dual Edge Modulation for Fastest Initial Response to

Transient Loading

• High Performance Operational Error Amplifier

• Digital Soft Start Ramp

• Dynamic Reference Injection

• Accurate Total Summing Current Amplifier

• Dual High Impedance Differential Voltage and Total

Current Sense Amplifiers

• Phase−to−Phase Dynamic Current Balancing

• “Lossless” DCR Current Sensing for Current Balancing

• True Differential Current Balancing Sense Amplifiers

for Each Phase

• Adaptive Voltage Positioning (AVP)

• Switching Frequency Range of 280 kHz – 600 kHz

• Startup into Pre−Charged Loads While Avoiding False OVP

• Power Saving Phase Shedding

• Vin Feed Forward Ramp Slope

• Over Voltage Protection (OVP) & Under Voltage

Protection (UVP)

• Over Current Protection (OCP)

• VR−RDY Output with Internal Delays

• These are Pb−Free Devices

Applications

• Desktop and Notebook Processors