Four-Phase Buck PWM Controller

® ISL6312A Data Sheet February 15, 2007 FN9290.2 Four-Phase Buck PWM Controller with Integrated MOSFET Drivers for Intel VR10, VR11, and AMD Applications The ISL6312A four-phase PWM control IC provides a precision voltage regulation system for advanced microprocessors. The integration of power MOSFET drivers into the controller IC marks a departure from the separate PWM controller and driver configuration of previous multiphase product families. By reducing the number of external parts, this integration is optimized for a cost and space saving power management solution. One outstanding feature of this controller IC is its multi-processor compatibility, allowing it to work with both Intel and AMD microprocessors. Included are programmable VID codes for Intel VR10, VR11, as well as AMD DAC tables. A unity gain, differential amplifier is provided for remote voltage sensing, compensating for any potential difference between remote and local grounds. The output voltage can also be positively or negatively offset through the use of a single external resistor. The ISL6312A also includes advanced control loop features for optimal transient response to load apply and removal. One of these features is highly accurate, fully differential, continuous DCR current sensing for load line programming and channel current balance. Active Pulse Positioning (APP) modulation is another unique feature, allowing for quicker initial response to high di/dt load transients. This controller also allows the user the flexibility to choose between PHASE detect or LGATE detect adaptive dead time schemes. This ability allows the ISL6312A to be used in a multitude of applications where either scheme is required. Protection features of this controller IC include a set of sophisticated overvoltage, undervoltage, and overcurrent protection. Furthermore, the ISL6312A includes protection against an open circuit on the remote sensing inputs. Combined, these features provide advanced protection for the microprocessor and power system. Features • Integrated Multiphase Power Conversion - 2-Phase or 3-Phase Operation with Internal Drivers - 4-Phase Operation with External PWM Driver Signal • Precision Core Voltage Regulation - Differential Remote Voltage Sensing - ±0.5% System Accuracy Over Temperature - Adjustable Reference-Voltage Offset • Optimal Transient Response - Active Pulse Positioning (APP) Modulation - Adaptive Phase Alignment (APA) • Fully Differential, Continuous DCR Current Sensing - Accurate Load Line Programming - Precision Channel Current Balancing • User Selectable Adaptive Dead Time Scheme - PHASE Detect or LGATE Detect for Application Flexibility • Variable Gate Drive Bias: 5V to 12V • Multi-Processor Compatible - Intel VR10 and VR11 Modes of Operation - AMD Mode of Operation • Microprocessor Voltage Identification Inputs - 8-bit DAC - Selectable between Intel’s Extended VR10, VR11, AMD 5-bit, and AMD 6-bit DAC Tables - Dynamic VID Technology • Overcurrent Protection • Load Current Indicator • Multi-Tiered Overvoltage Protection • Digital Soft-Start • Selectable Operation Frequency up to 1.5MHz Per Phase • Pb-Free Plus Anneal Available (RoHS Compliant) Ordering Information PART NUMBER (Note) PART MARKING TEMP. (°C) PACKAGE (Pb-Free) PKG. DWG. # ISL6312ACRZ* ISL6312 ACRZ 0 to +70 48 Ld 7x7 QFN L48.7x7 ISL6312AIRZ* ISL6312 AIRZ -40 to +85 48 Ld 7x7 QFN L48.7x7 NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. *Add “-T” suffix for tape and reel. 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2006, 2007. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL6312A Pinout ISL6312A (48 LD QFN) TOP VIEW PHASE3 38 UGATE3 LGATE3 PGOOD 37 36 EN 35 ISEN1+ 34 ISEN133 PHASE1 32 UGATE1 49 GND 31 BOOT1 30 LGATE1 29 PVCC1_2 28 LGATE2 27 BOOT2 26 UGATE2 25 PHASE2 13 COMP 14 FB 15 IOUT 16 VDIFF 17 RGND 18 VSEN 19 ISEN2+ 20 ISEN221 ISEN4+ 22 ISEN423 EN_PH4 24 PWM4 ISEN3+ BOOT3 40 PVCC3 42 ISEN343 VID5 VID6 VID7 46 48 VID4 VID3 VID2 VID1 VID0 VRSEL DRSEL OVPSEL SS VCC REF OFS 1 2 3 4 5 6 7 8 9 10 11 12 47 45 FS 44 41 39 ISL6312A Integrated Driver Block Diagram PVCC DRSEL BOOT UGATE PWM GATE CONTROL LOGIC SHOOTTHROUGH PROTECTION 20kΩ PHASE SOFT-START AND FAULT LOGIC 10kΩ LGATE 2 FN9290.2 February 15, 2007 ISL6312A Block Diagram PGOOD OPEN SENSE LINE PREVENTION VSEN x1 RGND VDIFF UNDERVOLTAGE DETECTION LOGIC SOFT-START AND FAULT LOGIC BOOT1 UGATE1 PHASE1 0.2V LGATE1 0.85V POWER-ON RESET VCC PVCC1_2 SS EN OVERVOLTAGE DETECTION LOGIC MOSFET DRIVER OVPSEL LOAD APPLY TRANSIENT ENHANCEMENT DRSEL CLOCK AND MODULATOR WAVEFORM GENERATOR VRSEL MODE / DAC SELECT FS BOOT2 MOSFET DRIVER UGATE2 PHASE2 LGATE2 PWM2 PWM1 VID7 VID6 VID5 VID4 VID3 VID2 VID1 VID0 REF E/A FB DYNAMIC VID D/A I_TRIP ∑ OC ∑ PWM3 ∑ PWM4 PH4 POR/ DETECT CHANNEL DETECT EN_PH4 PVCC3 ∑ BOOT3 MOSFET DRIVER CHANNEL CURRENT BALANCE I_AVG 1 N UGATE3 PHASE3 LGATE3 COMP OFS OFFSET I_AVG IOUT x1 OCP ∑ PWM4 SIGNAL LOGIC CH1 CURRENT SENSE CH2 CURRENT SENSE CH3 CURRENT SENSE CH4 CURRENT SENSE PWM4 VOCP ISEN1- ISEN1+ ISEN2- ISEN2+ ISEN3- ISEN3+ ISEN4- ISEN4+ GND 3 FN9290.2 February 15, 2007 ISL6312A Typical Application - ISL6312A (4-Phase) +12V FB COMP VSEN RGND +5V VCC PHASE1 VDIFF BOOT1 UGATE1 LGATE1 OFS FS REF PVCC1_2 ISEN1ISEN1+ +12V SS BOOT2 UGATE2 PHASE2 OVPSEL LGATE2 ISEN2ISEN2+ +12V PVCC3 LOAD ISL6312A VID7 VID6 VID5 VID4 VID3 VID2 VID1 VID0 VRSEL PGOOD +12V BOOT3 UGATE3 PHASE3 LGATE3 ISEN3ISEN3+ EN +12V IOUT BOOT VCC UGATE PVCC PHASE +12V EN_PH4 DRSEL PWM4 GND ISL6612 LGATE PWM GND ISEN4ISEN4+ 4 FN9290.2 February 15, 2007 ISL6312A Typical Application - ISL6312A with NTC Thermal Compensation (4-Phase) +12V FB COMP VSEN RGND +5V VCC PHASE1 VDIFF BOOT1 UGATE1 NTC PLACE IN CLOSE PROXIMITY LGATE1 OFS FS REF PVCC1_2 ISEN1ISEN1+ +12V SS BOOT2 UGATE2 PHASE2 OVPSEL LGATE2 ISEN2ISEN2+ +12V PVCC3 LOAD VID7 VID6 VID5 VID4 VID3 VID2 VID1 VID0 VRSEL PGOOD +12V ISL6312A BOOT3 UGATE3 PHASE3 LGATE3 ISEN3ISEN3+ +12V +12V EN IOUT EN_PH4 DRSEL BOOT VCC UGATE PVCC PHASE ISL6612 LGATE PWM4 GND ISEN4ISEN4+ PWM GND 5 FN9290.2 February 15, 2007 ISL6312A Absolute Maximum Ratings Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V Supply Voltage, PVCC . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +15V BOOT Voltage, VBOOT . . . . . . . . . . . . . . GND - 0.3V to GND + 36V BOOT to PHASE Voltage, VBOOT-PHASE . . . . . . -0.3V to 15V (DC) -0.3V to 16V (<10ns, 10µJ) PHASE Voltage, VPHASE . . . . . . . GND - 0.3V to 15V (PVCC = 12) GND - 8V (<400ns, 20µJ) to 24V (<200ns, VBOOT-PHASE = 12V) UGATE Voltage, VUGATE. . . . . . . . VPHASE - 0.3V to VBOOT + 0.3V VPHASE - 3.5V (<100ns Pulse Width, 2µJ) to VBOOT + 0.3V LGATE Voltage, VLGATE . . . . . . . . . . . GND - 0.3V to PVCC + 0.3V GND - 5V (<100ns Pulse Width, 2µJ) to PVCC+ 0.3V Input, Output, or I/O Voltage . . . . . . . . . GND - 0.3V to VCC + 0.3V ESD Classification . . . . . . . . . . . . . . . . . . . . . . . Class I JEDEC STD Thermal Information Thermal Resistance θJA (°C/W) θJC (°C/W) QFN Package (Notes 1, 2) . . . . . . . . . . +32 +3.5 Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . +150°C Maximum Storage Temperature Range . . . . . . . . . .-65°C to +150°C Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . +300°C Recommended Operating Conditions VCC Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5V ±5% PVCC Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . +5V to 12V ±5% Ambient Temperature (ISL6312ACRZ) . . . . . . . . . . . . 0°C to +70°C Ambient Temperature (ISL6312AIRZ) . . . . . . . . . . . .-40°C to +85°C CAUTION: Stress above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. NOTES: 1. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech Brief TB379. 2. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside. 3. Parameter magnitude guaranteed by design. Not 100% tested. Electrical Specifications PARAMETER BIAS SUPPLIES Input Bias Supply Current Recommended Operating Conditions, Unless Otherwise Specified. TEST CONDITIONS MIN TYP MAX UNITS IVCC; ENLL = high IPVCC1_2; ENLL = high IPVCC3; ENLL = high VCC rising VCC falling 15 2 1 4.25 3.75 4.25 3.60 20 4.3 2.1 4.38 3.88 4.38 3.88 25 6 3 4.50 4.00 4.50 4.00 mA mA mA V V V V Gate Drive Bias Current - PVCC1_2 Pin Gate Drive Bias Current - PVCC3 Pin VCC POR (Power-On Reset) Threshold PVCC POR (Power-On Reset) Threshold PVCC rising PVCC falling PWM MODULATOR Oscillator Frequency Accuracy, FSW Adjustment Range of Switching Frequency Oscillator Ramp Amplitude, VPP CONTROL THRESHOLDS ENLL Rising Threshold ENLL Hysteresis EN_PH4 Rising Threshold EN_PH4 Falling Threshold COMP Shutdown Threshold COMP falling 1.160 1.00 0.1 0.85 110 1.210 1.06 0.2 1.250 1.10 0.3 V mV V V V RT = 100kΩ (± 0.1%) (Note 3) (Note 3) 225 0.08 250 1.50 275 1.0 kHz MHz V 6 FN9290.2 February 15, 2007 ISL6312A