The ISL6561 controls microprocessor core voltage regulation by driving up to four synchronous rectified buck channels. Multiphase buck converters use interleaved timing to multiply the channel ripple frequency, reducing input and output ripple currents. Low ripple results in fewer components, lower component cost, reduced power consumption, and smaller implementation area.

Microprocessor loads can generate load transients at extremely fast edge rates. The ISL6561 features a high bandwidth control loop and >4MHz ripple frequency for optimal response to transients.

Today's microprocessors require a tightly controlled output voltage position versus load current (droop). The ISL6561 senses current by measuring the on resistance of the output inductor, rDS(on), or the voltage across the DCR during the lower MOSFET conduction interval through a patented technique. Current sensors provide the signals needed for precision droop, channel current balancing, and overcurrent protection.

The accuracy of the current sensing method is improved through the temperature compensation function of the ISL6561. As temperature increases, an increase in rDS(ON) or DCR can affect the falloff accuracy. The ISL6561 uses an internal temperature sensing element and provides programmable temperature compensation. If applied properly, temperature compensation can completely cancel out the effects of rDS(ON) or DCR temperature sensitivity.

A unity gain, differential amplifier provides the sense voltage. Any potential difference between remote and local grounds can be completely eliminated using telemetry amplifiers. Eliminate ground differences and improve adjustment and protection accuracy. A threshold-sensitive enable input can be used to precisely coordinate the startup of the ISL6561 with any other voltage rail. Dynamic-VID™ technology enables seamless dynamic video changes. Bias pin allows precise voltage bias setting independent of VID setting. The ISL6561 uses a 5V bias voltage and has a built-in shunt regulator, which can achieve a 12V bias voltage using only a small external current limiting resistor.

Features? Precision Multi-Stage Core Voltage Regulation - Differential Remote Voltage Sensing System Accuracy 0.5% Life, Load, Line and Temperature, Adjustable Reference Voltage Offset Wire Programming - Accurate Channel Current Balance Differentiation Current Sense - Low Cost, Lossless Current Sensing? Internal Shunt Regulator Voltage 5V, 12V Bias? VID input - 0.8375 v changed to 1.600 v 12.5 mv steps? Threshold-Sensitive enable function Synchronous drive motion? Overload protection? Package Options - QFN Compatible with JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Product Outline - QFN Near Chip Scale Package Memory; Improved PCB Efficiency, Thinner Profile