Intersil Corporation (NASDAQ: ISIL), a world leader in the design and manufacture of high-performance analog solutions,expanded its broad PWM (pulse width modulation) controller portfolio with the introduction of the ISL6316, a high-performance CPU multiphase core controller for Intel-based VRD (voltage regulator down) 10.X and EVRD (enterprise voltage regulator down) 10.X desktop, workstation and server motherboards.  Continuing Intersil’s strategy of providing the industry’s most precise VR10.X PWM controllers, the four-phase ISL6316 is the industry’s most accurate CPU core controller and includes thermal monitoring and tracking OCP (over-current protection) over temperature, with + or -0.5 percent system accuracy over the complete CPU voltage range. 

The temperature thresholds of the ISL6316 are programmable to enable the controller to communicate to the CPU and alert the system when the voltage regulator overheats (VRHOT), signaling the CPU to reduce its power consumption.  The ISL6316 is also able to turn on a CPU or system fan (VRFAN) signal to cool the CPU down or identify when the CPU overheats and inform it to shut down.  The ISL6316 is the industry’s only VR10.X and EVRD10.X CPU core controller with tracking OCP over temperature that is based on a single, external NTC (negative temperature coefficient) thermistor. 

“The current limit threshold of the ISL6316 is the same either at room temperature or at elevated temperatures inside a system chassis, “said George Lakkas, senior product marketing manager of Intersil’s Power Management group.  “This offers significant improvements in reliability in mission-critical applications, such as servers, routers, switchers, or storage area network (SAN) and network attached storage (NAS) systems.  The system designer can program the ISL6316, for example, to respond to an overload of 130A at an ambient temperature of 25 degrees Celsius and know that it will have the same current limit threshold of 130A at an ambient temperature of 60 degrees Celsius.”

Highest Precision, Accuracy and Performance
The ISL6316 controls microprocessor core voltage regulation by driving up to four synchronous-rectified buck channels in parallel.  Multiphase buck converter architecture uses interleaved timing to multiply channel ripple frequency and reduce input and output ripple currents.  Lower ripple results in fewer components, reducing overall component cost, power dissipation and board area. 
This device provides very accurate over-current protection, phase-to-phase current balance and loadline accuracy through differential current sensing as well as very precise voltage regulation through differential voltage sensing. Differential current sensing (measuring the current across the current sense element) ensures the multiphase converter eliminates any current measurement inaccuracy due to PCB (Printed Circuit Board) layout. The ISL6316 features adjustable precision reference voltage offset to enable precise loadline programming. The offset pin allows accurate voltage offset settings that are independent of VID (voltage identification) setting.

The ISL6316 senses current by measuring the voltage across the on-resistance (rDS(on)) of the lower MOSFETs (metal oxide silicon field effect transistors) or DCR (direct current resistance) of the output inductor.  The ISL6316 is paired with Intersil’s ISL6612/12A/13/13A/14/14A and ISL6605/08 FET drivers.  Dynamic VID technology allows seamless VID changes. 

Key Features
• Precision multiphase core voltage regulation
• Differential remote voltage sensing
• + or -0.5 percent system accuracy over life, load, line and temperature
• Adjustable precision reference voltage offset
• Precision rDS(on) or DCR current sensing
• Accurate loadline  programming
• Differential current sense
• Temperature-tracking OCP
• Thermal monitoring

Target Applications
• Desktop, workstation, server and industrial PC computer motherboards
• Voltage regulator modules (VRMs)
• Routers and switches
• ASIC core multiphase buck DC/DC converter on VRMs, point-of-load and DC/DC converters