DATASHEET ISL6398 FN8575 Rev 1.00 Advanced Linear EAPP Digital 6-Phase Green PWM Controller for Digital Power Aug 13, 2015 Management with NVM and AUTO Phase Shedding The ISL6398 is a smart and smallest 6-Phase Green PWM Features controller, designed for networking, datacenter, and POL 2 SMBus/PMBus/I C Compatible applications. It includes programmable functions and telemetries for easy use and system flexibility using SMBus, - Programmable IMAX, TMAX, BOOT, and address 2 PMBus, or I C interface, which is designed to program NVM - Programmable soft-start rate and DVID rate banks up to 8 different compensations and system -Up to 1.5MHz parameters. This minimizes external components and - NVM to store up to 8 Configurations with programmable significantly reduces design complexity and PCB area, and frequency, droop, auto, faults (OCP, UVP, CFP), etc. simplifies the manufacturing process. - No firmware requirement and hassle The ISL6398 utilizes Intersils proprietary Advanced Linear EAPP Advanced Linear EAPP Digital control scheme (patented) (Enhanced Active Pulse Positioning) Digital control scheme to - Digitally programmable compensation achieve the extremely fast linear transient response with fewer - Auto phase shedding option for greener environment output capacitors and overcomes many hurdles of traditional - Variable frequency control during load transients to digital approach, which uses non-linear, discrete control method reduce beat frequency oscillation for both voltage loop and current balance loop and runs into beat frequency oscillation and non-linear response. The ISL6398 - Linear control with evenly distributed PWM pulses for accurately monitors the load current via the IMON pin and better phase current balance during load transients reports this information via the READ IOUT register for power - Voltage feed-forward and ramp adjustable options management. The ISL6398 features auto-phase shedding. In low - High frequency compensation option power operation, the magnetic core and switching losses are - Active phase adding and dropping for enhanced light load significantly reduced with lower phase count operation, yielding efficiency high efficiency at light load. When APA is triggered, the dropped Phase doubler and coupled-inductor compatibility phase(s) are added back to sustain heavy load transient Differential remote voltage sensing with 0.5% accuracy response and efficiency. It optimizes the efficiency from light to Programmable minimum phase count operation full load for Greener Environment without sacrificing the transient performance. Programmable slew rate of dynamic VID with dynamic VID compensation (DVC) The ISL6398 senses the output current continuously by a dedicated current sense resistor or the DCR of the output Support 3-state 5V or 3.3V PWM DrMOS and driver inductor. The sensed current flows through a digitally Zero current shutdown with ISL6627 programmable 1% droop resistor for precision load line control. Precision resistor or DCR differential current sensing Current sensing circuits also provide the needed signals for - Accurate load-line (Droop) programming and control channel-current balancing, average overcurrent protection and - Accurate current monitoring and channel-current individual phase current limiting. The TM pin senses an NTC balancing with calibration capability thermistors temperature, which is internally digitized for thermal monitoring and for integrated thermal compensation of the True input current sensing for catastrophic failure protection current sense elements of the regulator. Average overcurrent protection and channel current limiting The ISL6398 features remote voltage sensing and completely High common mode current sense input (VCC-1.5V) eliminates any potential difference between remote and local Open sensing and single point of loop failure protection grounds. This improves regulation and protection accuracy. The Thermal monitoring and integrated compensation threshold-sensitive enable input is available to accurately coordinate the start-up of the ISL6398 with other voltage rails. 1- to 6-Phase option and up to 2MHz per phase Start-up into precharged load Pb-free (RoHS Compliant) 40 Ld 5x5 Plastic Package Applications High efficiency and high density digital power High performance multi-phase POL and network Cloud Computing, Router, Data Center and Storage General processor power FN8575 Rev 1.00 Page 1 of 57 Aug 13, 2015ISL6398 Fault Monitoring and Protection . 26 Table of Contents VR Ready Signal 26 Ordering Information 3 Overvoltage Protection . 26 Undervoltage Protection . 27 Driver Recommendation 4 Overcurrent Protection . 27 ISL6398 Internal Block Diagram . 5 Thermal Monitoring (VR HOT ) . 27 Temperature Compensation 28 Typical Application: 6-Phase VR with DrMOS and 2 Integrated Temperature Compensation 29 PMBus/SMBus/I C 6 Design Procedure . 29 Typical Application: 4-Phase VR with DrMOS and Dynamic VID Compensation (DVC) .30 2 PMBus/SMBus/I C 7 Programmable Compensation 30 Catastrophic Fault Protection . 30 Typical Application: 6-Phase VR for General Processor Power 8 Input Current Sensing 30 Typical Application: 12-Phase VR for Over-clocking Auto-phase Shedding . 31 Applications 9 Resistor Reader (Patented) . 32 Absolute Maximum Ratings 10 Memory Banks 33 2 Thermal Information 10 SMBus, PMBus and I C Operation 35 Recommended Operating Conditions .10 General Design Guide 49 Electrical Specifications 10 Power Stages 49 Current Sensing Resistor . 50 Functional Pin Descriptions 14 Load-line Regulation Resistor . 51 Operation .15 Output Filter Design . 51 Switching Frequency Selection 52 Multiphase Power Conversion . 15 Input Capacitor Selection 52 Interleaving . 15 PWM Modulation Scheme 16 Layout and Design Considerations 53 PWM Operation . 17 Pin Noise Sensitivity, Design and Layout Consideration . 53 DrMOS and Driver Compatibility . 17 Component Placement 55 Phase Doubler Compatibility 17 Precharged Start-up Capability 17 Powering Up And Open-Loop Test 55 Switching Frequency . 17 Voltage Regulator (VR) Design Materials 55 Current Sensing . 18 R and L/DCR Matching for Coupled inductor 19 Revision History . 56 SET Channel-current Balance . 20 About Intersil 56 Voltage Regulation (5mV and 10mV Mode) 20 Load-line Regulation . 23 Package Outline Drawing . 57 Dynamic VID 24 Operation Initialization 24 Enable and Disable 24 Soft-start . 25 Current Sense Output 25 FN8575 Rev 1.00 Page 2 of 57 Aug 13, 2015