DATASHEET ISL6334, ISL6334A FN6482 Rev 3.00 VR11.1, 4-Phase PWM Controller with Light-Load Efficiency Enhancement and May 6, 2016 Load Current Monitoring Features The ISL6334, ISL6334A control microprocessor core voltage Features regulation by driving up to 4 interleaved synchronous-rectified Intel VR11.1 compliant buck channels in parallel. This multiphase architecture results in multiplying channel ripple frequency and reducing input and Proprietary Active Pulse Positioning (APP) and Adaptive output ripple currents. Lower ripple results in fewer components, Phase Alignment (APA) modulation scheme lower cost, reduced power dissipation and smaller Proprietary active phase adding and dropping with diode implementation area. emulation scheme for high light-load efficiency Microprocessor loads can generate load transients with Precision multiphase core voltage regulation extremely fast edge rates and requires high efficiency at light - Differential remote voltage sensing load. The ISL6334, ISL6334A utilizes Intersils proprietary - 0.5% Closed-loop system accuracy over load, line and Active Pulse Positioning (APP), Adaptive Phase Alignment temperature (APA) modulation scheme, active phase adding and dropping - Bi-directional, adjustable reference-voltage offset to achieve and maintain the extremely fast transient response with fewer output capacitors and high efficiency from light to Precision resistor or DCR differential current sensing full load. - Accurate load line (droop) programming The ISL6334, ISL6334A is designed to be completely - Accurate channel-current balancing compliant with Intel VR11.1 specifications. It accurately - Accurate load current monitoring via IMON pin reports the load current via IMON pin to the microprocessor, which sends an active low PSI signal to the controller at low Microprocessor voltage identification input power mode. The controller then enters 1- or 2-phase - Dynamic VID technology for VR11.1 requirement operation with diode emulation option to reduce magnetic - 8-Bit VID, VR11 compatible core and switching losses, yielding high efficiency at light load. Average overcurrent protection and channel current limit After the PSI signal is deasserted, the dropped phase(s) are added back to sustain heavy load transient response and Precision overcurrent protection on IMON pin efficiency. Thermal monitoring and overvoltage protection Todays microprocessors require a tightly regulated output voltage Integrated programmable temperature compensation position versus load current (droop). The ISL6334, ISL6334A Integrated open sense line protection senses the output current continuously by utilizing patented techniques to measure the voltage across the dedicated current 1- to 4-phase operation, coupled inductor compatibility sense resistor or the DCR of the output inductor. The sensed Adjustable switching frequency up to 1MHz per phase current flows out of FB pin to develop the precision voltage drop Package option across the feedback resistor for droop control. Current sensing circuits also provide the needed signals for channel-current - QFN compliant to JEDEC PUB95 MO-220 QFN (Quad Flat balancing, average overcurrent protection and individual phase No Leads) package outline current limiting. An NTC thermistors temperature is sensed via Pb-free (RoHS Compliant) TM pin and internally digitized for thermal monitoring and for integrated thermal compensation of the current sense elements. A unity gain, differential amplifier is provided for remote voltage sensing and completely eliminates any potential difference between remote and local grounds. This improves regulation and protection accuracy. The threshold-sensitive enable input is available to accurately coordinate the start-up of the ISL6334, ISL6334A with any other voltage rail. Dynamic-VID technology allows seamless on-the-fly VID changes. The offset pin allows accurate voltage offset settings that are independent of VID setting. FN6482 Rev 3.00 Page 1 of 31 May 6, 2016ISL6334, ISL6334A Table of Contents Ordering Information 3 Pin Configuration 4 Controller and Driver Recommendation 4 ISL6334 and ISL6334A Block Diagram 5 Typical Application: 4-Phase VR with Integrated Thermal Compensation, PSI (DE and GVOT) 6 Typical Application - 4-Phase VR with 1-Phase PSI and without Diode Emulation and GVOT) 7 Typical Application -VR with External Thermal Compensation, 2-Phase PSI (no DE and GVOT) 8 Absolute Maximum Ratings . 9 Thermal Information . 9 Operating Conditions 9 Electrical Specifications 9 Functional Pin Description . 12 Operation . 13 Multiphase Power Conversion . 13 Interleaving . 13 PWM Modulation Scheme 14 PWM and PSI Operation . 14 Switching Frequency . 15 Current Sensing . 15 Channel-Current Balance . 16 Voltage Regulation 16 Load Line Regulation 19 Output-Voltage Offset Programming 20 Dynamic VID 20 Operation Initialization 20 Enable and Disable 20 Soft-Start . 21 Current Sense Output . 21 Fault Monitoring and Protection 22 VR RDY Signal 22 Undervoltage Detection 22 Overvoltage Protection . 22 Overcurrent Protection . 22 Thermal Monitoring (VR HOT/VR FAN) 23 Temperature Compensation 24 Integrated Temperature Compensation . 24 Design Procedure . 24 External Temperature Compensation . 25 General Design Guide . 25 Power Stages . 25 Current Sensing Resistor . 26 Load Line Regulation Resistor . 26 Compensation 27 Output Filter Design 27 Switching Frequency Selection 28 Input Capacitor Selection . 28 Layout Considerations 29 Component Placement . 29 Voltage-Regulator (VR) Design Materials 30 Revision History 30 About Intersil 30 Package Outline Drawing 31 FN6482 Rev 3.00 Page 2 of 31 May 6, 2016