Dual 3+1 PWM Controller with Current Monitor for IMVP-7/VR12™ CPUs ISL95839 Features The ISL95839 Pulse Width Modulation (PWM) controller IC provides a complete solution for IMVP-7/VR12™ compliant microprocessor and graphic processor core power supplies. It provides the control and protection for two Voltage Regulators (VRs). The first VR, typical for Vcore, incorporates 2 integrated drivers and can operate in 3-, 2- or 1-phase configurations. The second VR, typical for Graphics, incorporates 1 integrated driver. The two VRs share a serial control bus to communicate with the CPU and achieve lower cost and smaller board area compared with the two-chip approach. • Serial data bus • Dual outputs: - Configurable 3-, 2- or 1-phase for the 1st output using two integrated gate drivers - 2nd output using an integrated gate driver • R3™ Modulator - Excellent transient response - High light load efficiency • 0.5% system accuracy over-temperature Both VRs utilize Intersil’s Robust Ripple Regulator R3 Technology™. The R3 modulator has numerous advantages compared to traditional modulators, including faster transient response, variable switching frequency during load transients, and improved light load efficiency due to its ability to automatically change switching frequency. • Supports multiple current sensing methods - Lossless inductor DCR current sensing - Precision resistor current sensing • Differential remote voltage sensing • Programmable VBOOT voltage at start-up The ISL95839 has several other key features. Both outputs support either DCR current sensing with a single NTC thermistor for DCR temperature compensation, or more precise resistor current sensing if desired. Both outputs come with remote voltage sense, programmable VBOOT voltage, IMAX, and switching frequency, adjustable overcurrent protection and separate Power-Good signals. • Resistor programmable IMAX, switching frequency for both outputs • Output current monitor (IMON and IMONG) • Adaptive body diode conduction time reduction Applications • IMVP-7/VR12 compliant computers Vin VR2 Vin 0.91 VR1 VIN = 19V 0.90 ISL6208B DRIVER 0.89 ISL95839 0.88 VOUT (V) Vin 0.87 0.86 0.85 0.84 0.83 Vin VIN = 12V 0.82 VIN = 8V 0.81 0.80 0 6 12 18 24 30 36 42 48 54 60 66 IOUT (A) FIGURE 1. SIMPLIFIED APPLICATION CIRCUIT May 9, 2013 FN8315.0 1 FIGURE 2. LOAD LINE REGULATION CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2013. All Rights Reserved Intersil (and design) and R3 Technology™ are trademarks owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. ISL95839 Table of Contents Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Simplified Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Gate Driver Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multiphase R3™ Modulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diode Emulation and Period Stretching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Start-up Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Voltage Regulation and Load Line Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Current Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Differential Voltage Sensing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phase Current Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CCM Switching Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynamic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VR_HOT#/ALERT# Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FB2 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adaptive Body Diode Conduction Time Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Protections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supported Data and Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 10 11 12 12 16 16 16 18 18 19 19 20 20 20 21 Key Component Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Inductor DCR Current-Sensing Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Resistor Current-Sensing Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Compensator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Programming Resistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Current Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Slew Rate Compensation Circuit for VID Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Typical Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 About Intersil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2 FN8315.0 May 9, 2013 ISL95839 Ordering Information PART NUMBER (Notes 1, 2, 3) ISL95839HRTZ TEMP. RANGE (°C) PART MARKING 95839 HRTZ PACKAGE (Pb-Free) -10 to +100 40 Ld 5x5 TQFN PKG. DWG. # L40.5x5 NOTES: 1. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications. 2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is 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. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL95839. For more information on MSL please see techbrief TB363. Pin Configuration UGATE1G BOOT1G PHASE1G LGATE1G VR_ON PGOODG COMPG FBG RTNG ISUMNG ISL95839 (40 LD TQFN) TOP VIEW 40 39 38 37 36 35 34 33 32 31 ISUMPG 1 30 BOOT2 IMONG 2 29 UGATE2 IMON 3 28 PHASE2 NTCG 4 27 LGATE2 SCLK 5 26 VCCP GND PAD (BOTTOM) ALERT# 6 25 VDD SDA 7 24 PWM3 VR_HOT# 8 23 LGATE1 FB2 9 22 PHASE1 NTC 10 21 UGATE1 BOOT1 PGOOD COMP FB RTN ISUMN ISEN1 ISUMP ISEN2 ISEN3 11 12 13 14 15 16 17 18 19 20 Pin Descriptions PIN # SYMBOL 2 IMONG Output current monitor for VR2. 3 IMON Output current monitor for VR1. 4 NTCG The second thermistor input to VR_HOT# circuit. Use it to monitor VR2 temperature. 5, 6, 7 DESCRIPTION SCLK, ALERT#, Communication bus between the CPU and the VRs. SDA 8 VR_HOT# Open drain thermal overload output indicator. Can be considered part of communication bus with CPU. 9 FB2 There is a switch between the FB2 pin and the FB pin. The switch is on when VR1 is in 3-phase and 2-phase mode and is off in 1-phase mode. The components connecting to FB2 are used to adjust the compensation in 1-phase mode to achieve optimum performance for VR1. 10 NTC One of the thermistor inputs to VR_HOT# circuit. Use it to monitor VR1 temperature. 11 ISEN3 ISEN3 is the individual current sensing for VR1 phase 3. 3 FN8315.0 May 9, 2013 ISL95839 Pin Descriptions (Continued) PIN # SYMBOL DESCRIPTION 12 ISEN2 Individual current sensing for VR1 Phase 2. When ISEN2 and PWM3 are both pulled to 5V VDD, the controller will disable VR1 Phases 3 and 2. 13 ISEN1 Individual current sensing for VR1 Phase 1. 14, 15 ISUMP, ISUMN VR1 droop current sense input. 16 RTN VR1 remote voltage sensing return. 17 FB 18 COMP This pin is the output of the error amplifier for VR1. Also, a resistor from this pin to GND programs IMAX for VR1, and VBOOT for both VR1 and VR2. 19 PGOOD Power-Good open-drain output indicating when VR1 is able to supply regulated voltage. Pull up externally with a 680Ω resistor to VCCP or 1.9kΩ to 3.3V. 20 BOOT1 Connect an MLCC capacitor across the BOOT1 and the PHASE1 pins. The boot capacitor is charged through an internal boot diode connected from the VCCP pin to the BOOT1 pin, each time the PHASE1 pin drops below VCCP minus the voltage dropped across the internal boot diode. 21 UGATE1 Output of VR1 Phase-1 high-side MOSFET gate driver. Connect the UGATE1 pin to the gate of the Phase-1 high-side MOSFET. 22 PHASE1 Current return path for the VR1 Phase-1 high-side MOSFET gate driver. Connect the PHASE1 pin to the node consisting of the high-side MOSFET source, the low-side MOSFET drain, and the output inductor of VR1 Phase 1. 23 LGATE1 Output of VR1 Phase-1 low-side MOSFET gate driver. Connect the LGATE1 pin to the gate of VR1 Phase-1 low-side MOSFET. 24 PWM3 PWM output for VR1 Phase 3. When PWM3 is pulled to 5V VDD, the controller will disable VR1 Phase 3. 25 VDD 5V bias power. 26 VCCP Input voltage bias for the internal gate drivers. Connect +5V to the VCCP pin. Decouple with at least 1µF of an MLCC capacitor. 27 LGATE2 Output of VR1 Phase-2 low-side MOSFET gate driver. Connect the LGATE2 pin to the gate of VR1 Phase-2 low-side MOSFET. 28 PHASE2 Current return path for VR1 Phase-2 high-side MOSFET gate driver. Connect the PHASE2 pin to the node consisting of the high-side MOSFET source, the low-side MOSFET drain, and the output inductor of VR1 Phase 2. 29 UGATE2 Output of VR1 Phase-2 high-side MOSFET gate driver. Connect the UGATE2 pin to the gate of VR1 Phase-2 high-side MOSFET. 30 BOOT2 Connect an MLCC capacitor across the BOOT2 and the PHASE2 pins. The boot capacitor is charged through an internal boot diode connected from the VCCP pin to the BOOT2 pin, each time the PHASE2 pin drops below VCCP minus the voltage dropped across the internal boot diode. 31 BOOT1G Connect an MLCC capacitor across the BOOT1G and the PHASE1G pins. The boot capacitor is charged through an internal boot diode connected from the VCCP pin to the BOOT1G pin, each time the PHASE1G pin drops below VCCP minus the voltage dropped across the internal boot diode. 32 UGATE1G Output of VR2 Phase-1 high-side MOSFET gate driver. Connect the UGATE1G pin to the gate of VR2 Phase-1 high-side MOSFET. 33 PHASE1G Current return path for VR2 Phase-1 high-side MOSFET gate driver. Connect the PHASE1G pin to the node consisting of the high-side MOSFET source, the low-side MOSFET drain, and the output inductor of VR2 Phase 1. 34 LGATE1G Output of VR2 Phase-1 low-side MOSFET gate driver. Connect the LGATE1G pin to the gate of VR2 Phase-1 low-side MOSFET. 35 VR_ON 36 PGOODG Power-Good open-drain output indicating when VR2 is able to supply regulated voltage. Pull-up externally with a 680Ω resistor to VCCP or 1.9kΩ to 3.3V. 37 COMPG This pin is the output of the error amplifier for VR2. Also, a resistor from this pin to GND programs IMAX for VR2 and TMAX for both VR1 and VR2. 38 FBG 39 RTNG 40, 1 ISUMNG and ISUMPG Bottom Pad GND This pin is the inverting input of the error amplifier for VR1. Controller enable input. A high level logic signal on this pin enables the controller. This pin is the inverting input of the error amplifier for VR2. VR2 remote voltage sensing return. VR2 droop current sense input. When ISUMNG is pulled to 5V VDD, all the communication to VR2 is disabled. Signal common of the IC. Unless otherwise stated, signals are referenced to the GND pin. In addition, it is the return path for all the low-side MOSFET gate drivers. It should also be used as the thermal pad for heat removal. 4 FN8315.0 May 9, 2013 ISL95839 Block Diagram COMPG + RTNG Σ + + _ FBG E/A BOOT1G VR2 MODULATOR IDROOPG ISUMPG + ISUMNG _ DRIVER UGATE1G PHASE1G CURRENT SENSE DRIVER LGATE1G PGOODG IMONG OC FAULT OV FAULT NTCG T_MONITOR TEMP MONITOR NTC VDD VR_HOT# VCCP IMAX VBOOT TMAX SET (A/D) PROG VR_ON SDA DIGITAL INTERFACE ALERT# A/D IDROOPG IDROOP D/A DAC2 DAC1 MODE SCLK PWM3 MODE2 MODE1 BOOT2 VREADY DRIVER UGATE2 PHASE2 COMP + RTN FB FB2 Σ + VR1 MODULATOR + _ FB2 CIRCUIT E/A DRIVER BOOT1 IDROOP DRIVER ISUMP + ISUMN _ CURRENT SENSE UGATE1 PHASE1 ISEN3 ISEN2 LGATE2 DRIVER CURRENT BALANCING OC FAULT ISEN1 LGATE1 PGOOD IBAL FAULT OV FAULT IMON 5 GND FN8315.0 May 9, 2013 ISL95839 Simplified Application Circuit +5V VDD BOOT1G NTCG oC Vin VCCP Rntcg UGATE1G PGOODG PGOODG L4 PHASE1G GT Vcore LGATE1G ISUMPG COMPG Rng RCOMPG Rig Vsumng ISUMNG FBG Rdroopg Rsum4 oC Cng Cvsumng Rimong IMONG Cimong V+5 VCCSENSEG VSSSENSEG Vin RTNG VCC UGATE PHASE ISL6208 BOOT PWM LGATE GND L3 FCCM PWM3 SDA ALERT# SCLK SDA ALERT# SCLK BOOT2 ISL95839 UGATE2 L2 PHASE2 CPU Vcore LGATE2 Rntc BOOT1 NTC oC L1 UGATE1 VR_HOT# PGOOD VR_ON VR_HOT# PGOOD VR_ON PHASE1 LGATE1 Rsum3 FB2 ISUMP Rsum2 Rn oC Cn COMP RCOMP Ri Vsumn ISUMN FB Cisen1 Cisen2 Cisen3 Rdroop Rsum1 Cvsumn Risen3 ISEN3 Risen2 ISEN2 Risen1 ISEN1 VCCSENSE VSSSENSE RTN IMON Rimon GND Cimon FIGURE 3. TYPICAL ISL95839 APPLICATION CIRCUIT USING INDUCTOR DCR SENSING 6 FN8315.0 May 9, 2013 ISL95839 Absolute Maximum Ratings Thermal Information Supply Voltage, VDD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +7V Battery Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +28V Boot Voltage (BOOT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +33V Boot-to-Phase Voltage (BOOT-PHASE) -0.3V to +7V(DC) . . . . . . . . . . . . . . . .-0.3V to +9V (<10ns) Phase Voltage (PHASE) . . . . . . . . . . . . . . . . -7V (<20ns Pulse Width, 10µJ) UGATE Voltage (UGATE) . . . . . . . . . . . . . . . . . . . PHASE - 0.3V (DC) to BOOT . . . . . . . . . . . . . . . . . . . . PHASE - 5V (<20ns Pulse Width, 10µJ) to BOOT LGATE Voltage . . . . . . . . . . . . -2.5V (<20ns Pulse Width, 5µJ) to VDD+0.3V All Other Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to (VDD +0.3V) Open Drain Outputs, PGOOD, VR_HOT#, ALERT#. . . . . . . . . . -0.3V to +7V ESD Rating Human Body Model (Tested per JESD22-A114E) . . . . . . . . . . . . . . . . 2kV Machine Model (Tested per JESD22-A115-A) . . . . . . . . . . . . . . . . . . 200V Charged Device Model (Tested per JESD22-C101A) . . . . . . . . . . . . . . 1k Latch Up (Tested per JESD-78B; Class 2, Level A) . . . . . . . . . . . . . . 100mA Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W) 40 Ld TQFN Package (Notes 4, 5) . . . . . . . 32 4 Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .+150°C Maximum Storage Temperature Range . . . . . . . . . . . . . .-65°C to +150°C Maximum Junction Temperature (Plastic Package) . . . . . . . . . . . .+150°C Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Supply Voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5V ±5% Battery Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +4.75V to 25V Ambient Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-10°C to +100°C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-10°C to +125°C CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTES: 4. 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. 5. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside. Electrical Specifications Operating Conditions: VDD = 5V, TA = -10°C to +100°C, fSW = 300kHz, unless otherwise noted. Boldface limits apply over the operating temperature range, -10°C to +100°C PARAMETER SYMBOL TEST CONDITIONS MIN (Note 6) TYP MAX (Note 6) UNITS 6.4 8.0 mA 1 µA 4.5 V INPUT POWER SUPPLY +5V Supply Current IVDD VR_ON = 1V VR_ON = 0V POWER-ON-RESET THRESHOLDS VDD Power-On-Reset Threshold VIN Power-On-Reset Threshold VDDPORr VDD rising VDDPORf VDD falling 4.35 4.00 VINPOR 4.15 4.40 V 4.75 V SYSTEM AND REFERENCES System Accuracy %Error (VOUT) No load; closed loop, active mode range, VID = 0.75V to 1.52V, VID = 0.5V to 0.745V VID = 0.25V to 0.495V -0.5 +0.5 % -6 +6 mV +10 mV 1.1055 V -10 1.0945 Internal VBOOT 1.100 Maximum Output Voltage VOUT(max) VID = [11111111] 1.52 V Minimum Output Voltage VOUT(min) VID = [00000001] 0.25 V CHANNEL FREQUENCY 300kHz Configuration fSW_300k 277 300 323 kHz 350kHz Configuration fSW_350k 324 350 376 kHz 400kHz Configuration fSW_400k 370 400 430 kHz 450kHz Configuration fSW_450k 412 445 478 kHz +0.2 mV AMPLIFIERS IFB = 0A Current-Sense Amplifier Input Offset Error Amp DC Gain AV0 Error Amp Gain-Bandwidth Product GBW 7 CL = 20pF -0.2 90 dB 18 MHz FN8315.0 May 9, 2013 ISL95839 Electrical Specifications Operating Conditions: VDD = 5V, TA = -10°C to +100°C, fSW = 300kHz, unless otherwise noted. Boldface limits apply over the operating temperature range, -10°C to +100°C (Continued) PARAMETER SYMBOL TEST CONDITIONS MIN (Note 6) TYP MAX (Note 6) UNITS 1 mV ISEN Imbalance Voltage Maximum of ISENs - Minimum of ISENs Input Bias Current 20 nA POWER-GOOD AND PROTECTION MONITORS PGOOD Low Voltage VOL IPGOOD = 4mA PGOOD Leakage Current IOH PGOOD = 3.3V PGOOD Delay tpgd 0.15 0.4 V 1 µA 2.6 ms ALERT# Low 7 12 VR_HOT# Low 7 Ω 12 Ω ALERT# Leakage Current 1 µA VR_HOT# Leakage Current 1 µA CURRENT MONITOR IMON and IMONG Output Current IIMON ICCMAX Alert Trip Voltage VIMONMAX ICCMAX Alert Reset Voltage ISUM- pin current = 40µA 9.7 10 10.3 µA ISUM- pin current = 20µA 4.8 5 5.2 µA ISUM- pin current = 4µA 0.875 1 1.125 µA Rising 1.2 Falling 1.14 V 1.8 V IMON Voltage Clamp V GATE DRIVER UGATE Pull-Up Resistance RUGPU 200mA Source Current 1.0 UGATE Source Current IUGSRC UGATE - PHASE = 2.5V 2.0 UGATE Sink Resistance RUGPD 250mA Sink Current 1.0 UGATE Sink Current IUGSNK UGATE - PHASE = 2.5V 2.0 LGATE Pull-Up Resistance RLGPU 250mA Source Current 1.0 LGATE Source Current ILGSRC LGATE - VSSP = 2.5V 2.0 1.5 Ω A 1.5 Ω 1.5 Ω A A LGATE Sink Resistance RLGPD 250mA Sink Current 0.5 LGATE Sink Current ILGSNK LGATE - VSSP = 2.5V 4.0 0.9 Ω A UGATE to LGATE Deadtime tUGFLGR UGATE falling to LGATE rising, no load 17 ns LGATE to UGATE Deadtime tLGFUGR LGATE falling to UGATE rising, no load 29 ns 15 Ω 0.2 µA BOOTSTRAP SWITCH On Resistance RF Reverse Leakage IR VR = 25V PROTECTION Overvoltage Threshold OVH VSEN rising above setpoint for >1µs 145 175 200 One ISEN above another ISEN for >3.2ms VR1 Overcurrent Threshold 3-Phase - PS0 and 1-Phase - all states 56 60 64 µA 3-Phase - PS1 37 40 43 µA 3-Phase - PS2 18 20 22 µA 2-Phase - PS0 56 60 64 µA VR2 Overcurrent Threshold 8 23 mV Current Imbalance Threshold (VR1) mV 2-Phase - PS1 and PS2 27 30 33 µA 1-Phase - all states 56 60 64 µA FN8315.0 May 9, 2013 ISL95839 Electrical Specifications Operating Conditions: VDD = 5V, TA = -10°C to +100°C, fSW = 300kHz, unless otherwise noted. Boldface limits apply over the operating temperature range, -10°C to +100°C (Continued) PARAMETER SYMBOL TEST CONDITIONS MIN (Note 6) TYP MAX (Note 6) UNITS 0.3 V LOGIC THRESHOLDS VR_ON Input Low VIL VR_ON Input High VIH 0.7 V PWM3 PWM Output Low V0L Sinking 5mA PWM Output High V0H Sourcing 5mA PWM Tri-State Leakage 1.0 3.5 PWM = 2.5V V 4.2 V 1 µA NTC and NTCG NTC Source Current NTC = 1.3V 58 60 62 µA VR_HOT# Trip Voltage (VR1 and VR2) Falling 0.881 0.893 0.905 V VR_HOT# Reset Voltage (VR1 and VR2) Rising 0.924 0.936 0.948 V Therm_Alert Trip Voltage (VR1 and VR2) Falling 0.920 0.932 0.944 V Therm_Alert Reset Voltage (VR1 and VR2) Rising 0.962 0.974 0.986 V -1 0 INPUTS VR_ON Leakage Current IVR_ON VR_ON = 0V VR_ON = 1V SCLK, SDA Leakage 3.5 VR_ON = 0V, SCLK and SDA = 0V and 1V -1 VR_ON = 1V, SCLK and SDA = 1V -2 µA 6 µA 1 µA 1 µA VR_ON = 1V, SDA = 0V -21 µA VR_ON = 1V, SCLK= 0V -42 µA SLEW RATE (For VID Change) Fast Slew Rate 10 mV/µs Slow Slew Rate 2.5 mV/µs NOTE: 6. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design. 9 FN8315.0 May 9, 2013 ISL95839 Gate Driver Timing Diagram PWM tLGFUGR tFU tRU 1V UGATE 1V LGATE tRL tFL tUGFLGR Theory of Operation Multiphase R3™ Modulator The ISL95839 is a multiphase regulator implementing Intel™ IMVP-7/VR12™ protocol. It has two voltage regulators, VR1 and VR2, on one chip. VR1 can be programmed for 1-, 2- or 3-phase operation, and VR2 is 1-phase operation. The following description is based on VR1, but also applies to VR2 because they are based on the same architecture. than conventional hysteretic mode and fixed PWM mode controllers. Unlike conventional hysteretic mode converters, the ISL95839 uses an error amplifier that allows the controller to maintain a 0.5% output voltage accuracy. MASTER CLOCK gmVo The ISL95839 uses Intersil patented R3™ (Robust Ripple Regulator™) modulator. The R3™ modulator combines the best features of fixed frequency PWM and hysteretic PWM while eliminating many of their shortcomings. Figure 4 conceptually shows the multiphase R3™ modulator circuit, and Figure 5 shows the operation principles. Inside the IC, the modulator uses the master clock circuit to generate the clocks for the slave circuits. The modulator discharges the ripple capacitor Crm with a current source equal to gmVo, where gm is a gain factor. Crm voltage Vcrm is a sawtooth waveform traversing between the VW and COMP voltages. It resets to VW when it hits COMP, and generates a one-shot master clock signal. A phase sequencer distributes the master clock signal to the slave circuits. If VR1 is in 3-phase mode, the master clock signal will be distributed to the three phases, and the Clock1~3 signals will be 120° out-of-phase. If VR1 is in 2-phase mode, the master clock signal will be distributed to Phases 1 and 2, and the Clock1 and Clock2 signals will be 180° out-of-phase. If VR1 is in 1-phase mode, the master clock signal will be distributed to Phase 1 only and will be the Clock1 signal. Each slave circuit has its own ripple capacitor Crs, whose voltage mimics the inductor ripple current. A gm amplifier converts the inductor voltage into a current source to charge and discharge Crs. The slave circuit turns on its PWM pulse upon receiving the clock signal, and the current source charges Crs. When Crs voltage VCrs hits VW, the slave circuit turns off the PWM pulse, and the current source discharges Crs. MASTER CLOCK CIRCUIT MASTER CLOCK COMP Phase Vcrm Sequencer VW Clock1 Clock2 Clock3 Crm SLAVE CIRCUIT 1 VW Clock1 S R Q PWM1 Phase1 L1 IL1 Vcrs1 Vo Co gm Crs1 SLAVE CIRCUIT 2 VW Clock2 S R Q PWM2 Phase2 L2 IL2 Vcrs2 gm Crs2 SLAVE CIRCUIT 3 VW Clock3 S R Q PWM3 Phase3 L3 IL3 Vcrs3 gm Crs3 FIGURE 4. R3™ MODULATOR CIRCUIT Since the controller works with Vcrs, which are large-amplitude and noise-free synthesized signals, it achieves lower phase jitter 10 FN8315.0 May 9, 2013 ISL95839 VW HYSTERETIC W INDOW Vcrm COMP Master Clock rises as the COMP voltage rises, making the PWM pulses wider. During load release response, the COMP voltage falls. It takes the master clock circuit longer to generate the next master clock signal so the PWM pulse is held off until needed. The VW voltage falls as the COMP voltage falls, reducing the current PWM pulse width. This kind of behavior gives the controller excellent response speed. The fact that all the phases share the same VW window voltage also ensures excellent dynamic current balance among phases. Clock1 PW M1 Diode Emulation and Period Stretching Clock2 PW M2 Clock3 Phase PW M3 UGATE VW LGATE Vcrs2 Vcrs3 Vcrs1 FIGURE 5. R3™ MODULATOR OPERATION PRINCIPLES IN STEADY STATE IL FIGURE 7. DIODE EMULATION ISL95839 can operate in diode emulation (DE) mode to improve light load efficiency. In DE mode, the low-side MOSFET conducts when the current is flowing from source to drain and doesn’t allow reverse current, emulating a diode. As Figure 7 shows, when LGATE is on, the low-side MOSFET carries current, creating negative voltage on the phase node due to the voltage drop across the ON-resistance. The controller monitors the current through monitoring the phase node voltage. It turns off LGATE when the phase node voltage reaches zero to prevent the inductor current from reversing the direction and creating unnecessary power loss. VW COMP Vcrm Master Clock Clock1 If the load current is light enough, as Figure 7 shows, the inductor current will reach and stay at zero before the next phase node pulse and the regulator is in discontinuous conduction mode (DCM). If the load current is heavy enough, the inductor current will never reach 0A, and the regulator is in CCM although the controller is in DE mode. PWM1 Clock2 PWM2 Clock3 PWM3 VW Vcrs1 Vcrs3 Vcrs2 FIGURE 6. R3™ MODULATOR OPERATION PRINCIPLES IN LOAD INSERTION RESPONSE Figure 6 shows the operation principles during load insertion response. The COMP voltage rises during load insertion, generating the master clock signal more quickly, so the PWM pulses turn on earlier, increasing the effective switching frequency, which allows for higher control loop bandwidth than conventional fixed frequency PWM controllers. The VW voltage 11 Figure 8 shows the operation principle in diode emulation mode at light load. The load gets incrementally lighter in the three cases from top to bottom. The PWM on-time is determined by the VW window size, therefore is the same, making the inductor current triangle the same in the three cases. The controller clamps the master ripple capacitor voltage Vcrm and the slave ripple capacitor voltage Vcrs in DE mode to make it mimic the inductor current. It takes the Vcrm longer to hit COMP, naturally stretching the switching period. The inductor current triangles move further apart from each other such that the inductor current average value is equal to the load current. The reduced switching frequency helps increase light load efficiency. FN8315.0 May 9, 2013 ISL95839 TABLE 1. VID TABLE CCM/DCM BOUNDARY VW VID Vcrs HEX VO (V) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0.00000 0 0 0 0 0 0 0 1 0 1 0.25000 0 0 0 0 0 0 1 0 0 2 0.25500 0 0 0 0 0 0 1 1 0 3 0.26000 0 0 0 0 0 1 0 0 0 4 0.26500 0 0 0 0 0 1 0 1 0 5 0.27000 0 0 0 0 0 1 1 0 0 6 0.27500 0 0 0 0 0 1 1 1 0 7 0.28000 0 0 0 0 1 0 0 0 0 8 0.28500 0 0 0 0 1 0 0 1 0 9 0.29000 0 0 0 0 1 0 1 0 0 A 0.29500 0 0 0 0 1 0 1 1 0 B 0.30000 0 0 0 0 1 1 0 0 0 C 0.30500 0 0 0 0 1 1 0 1 0 D 0.31000 0 0 0 0 1 1 1 0 0 E 0.31500 0 0 0 0 1 1 1 1 0 F 0.32000 0 0 0 1 0 0 0 0 1 0 0.32500 0 0 0 1 0 0 0 1 1 1 0.33000 0 0 0 1 0 0 1 0 1 2 0.33500 0 0 0 1 0 0 1 1 1 3 0.34000 0 0 0 1 0 1 0 0 1 4 0.34500 0 0 0 1 0 1 0 1 1 5 0.35000 0 0 0 1 0 1 1 0 1 6 0.35500 0 0 0 1 0 1 1 1 1 7 0.36000 0 0 0 1 1 0 0 0 1 8 0.36500 0 0 0 1 1 0 0 1 1 9 0.37000 0 0 0 1 1 0 1 0 1 A 0.37500 0 0 0 1 1 0 1 1 1 B 0.38000 0 0 0 1 1 1 0 0 1 C 0.38500 Voltage Regulation and Load Line Implementation 0 0 0 1 1 1 0 1 1 D 0.39000 0 0 0 1 1 1 1 0 1 E 0.39500 After the start sequence, the controller regulates the output voltage to the value set by the VID information per Table 1. The controller will control the no-load output voltage to an accuracy of ±0.5% over the range of 0.25V to 1.52V. A differential amplifier allows voltage sensing for precise voltage regulation at the microprocessor die. 0 0 0 1 1 1 1 1 1 F 0.40000 0 0 1 0 0 0 0 0 2 0 0.40500 0 0 1 0 0 0 0 1 2 1 0.41000 0 0 1 0 0 0 1 0 2 2 0.41500 0 0 1 0 0 0 1 1 2 3 0.42000 0 0 1 0 0 1 0 0 2 4 0.42500 0 0 1 0 0 1 0 1 2 5 0.43000 0 0 1 0 0 1 1 0 2 6 0.43500 iL VW LIGHT DCM Vcrs iL DEEP DCM VW Vcrs iL FIGURE 8. PERIOD STRETCHING Start-up Timing With the controller's VDD voltage above the POR threshold, the start-up sequence begins when VR_ON exceeds the logic high threshold. Figure 9 shows the typical start-up timing of VR1 and VR2. The controller uses digital soft-start to ramp-up DAC to the voltage programmed by the SetVID command. PGOOD is asserted high and ALERT# is asserted low at the end of the ramp up. Similar results occur if VR_ON is tied to VDD, with the soft-start sequence starting 2.6ms after VDD crosses the POR threshold. VDD SLEW RATE VR_ON 2.5mV/µs VID COMMAND VOLTAGE VID 2.6ms DAC PGOOD …... ALERT# FIGURE 9. VR1 SOFT-START WAVEFORMS 12 FN8315.0 May 9, 2013 ISL95839 TABLE 1. VID TABLE (Continued) TABLE 1. VID TABLE (Continued) VID VID HEX VO (V) 7 6 5 4 3 2 1 0 7 0.44000 0 1 0 0 1 1 1 0 4 E 0.63500 2 8 0.44500 0 1 0 0 1 1 1 1 4 F 0.64000 1 2 9 0.45000 0 1 0 1 0 0 0 0 5 0 0.64500 1 0 2 A 0.45500 0 1 0 1 0 0 0 1 5 1 0.65000 0 1 1 2 B 0.46000 0 1 0 1 0 0 1 0 5 2 0.65500 1 1 0 0 2 C 0.46500 0 1 0 1 0 0 1 1 5 3 0.66000 0 1 1 0 1 2 D 0.47000 0 1 0 1 0 1 0 0 5 4 0.66500 1 0 1 1 1 0 2 E 0.47500 0 1 0 1 0 1 0 1 5 5 0.67000 0 1 0 1 1 1 1 2 F 0.48000 0 1 0 1 0 1 1 0 5 6 0.67500 0 0 1 1 0 0 0 0 3 0 0.48500 0 1 0 1 0 1 1 1 5 7 0.68000 0 0 1 1 0 0 0 1 3 1 0.49000 0 1 0 1 1 0 0 0 5 8 0.68500 0 0 1 1 0 0 1 0 3 2 0.49500 0 1 0 1 1 0 0 1 5 9 0.69000 0 0 1 1 0 0 1 1 3 3 0.50000 0 1 0 1 1 0 1 0 5 A 0.69500 0 0 1 1 0 1 0 0 3 4 0.50500 0 1 0 1 1 0 1 1 5 B 0.70000 0 0 1 1 0 1 0 1 3 5 0.51000 0 1 0 1 1 1 0 0 5 C 0.70500 0 0 1 1 0 1 1 0 3 6 0.51500 0 1 0 1 1 1 0 1 5 D 0.71000 0 0 1 1 0 1 1 1 3 7 0.52000 0 1 0 1 1 1 1 0 5 E 0.71500 0 0 1 1 1 0 0 0 3 8 0.52500 0 1 0 1 1 1 1 1 5 F 0.72000 0 0 1 1 1 0 0 1 3 9 0.53000 0 1 1 0 0 0 0 0 6 0 0.72500 0 0 1 1 1 0 1 0 3 A 0.53500 0 1 1 0 0 0 0 1 6 1 0.73000 0 0 1 1 1 0 1 1 3 B 0.54000 0 1 1 0 0 0 1 0 6 2 0.73500 0 0 1 1 1 1 0 0 3 C 0.54500 0 1 1 0 0 0 1 1 6 3 0.74000 0 0 1 1 1 1 0 1 3 D 0.55000 0 1 1 0 0 1 0 0 6 4 0.74500 0 0 1 1 1 1 1 0 3 E 0.55500 0 1 1 0 0 1 0 1 6 5 0.75000 0 0 1 1 1 1 1 1 3 F 0.56000 0 1 1 0 0 1 1 0 6 6 0.75500 0 1 0 0 0 0 0 0 4 0 0.56500 0 1 1 0 0 1 1 1 6 7 0.76000 0 1 0 0 0 0 0 1 4 1 0.57000 0 1 1 0 1 0 0 0 6 8 0.76500 0 1 0 0 0 0 1 0 4 2 0.57500 0 1 1 0 1 0 0 1 6 9 0.77000 0 1 0 0 0 0 1 1 4 3 0.58000 0 1 1 0 1 0 1 0 6 A 0.77500 0 1 0 0 0 1 0 0 4 4 0.58500 0 1 1 0 1 0 1 1 6 B 0.78000 0 1 0 0 0 1 0 1 4 5 0.59000 0 1 1 0 1 1 0 0 6 C 0.78500 0 1 0 0 0 1 1 0 4 6 0.59500 0 1 1 0 1 1 0 1 6 D 0.79000 0 1 0 0 0 1 1 1 4 7 0.60000 0 1 1 0 1 1 1 0 6 E 0.79500 0 1 0 0 1 0 0 0 4 8 0.60500 0 1 1 0 1 1 1 1 6 F 0.80000 0 1 0 0 1 0 0 1 4 9 0.61000 0 1 1 1 0 0 0 0 7 0 0.80500 0 1 0 0 1 0 1 0 4 A 0.61500 0 1 1 1 0 0 0 1 7 1 0.81000 0 1 0 0 1 0 1 1 4 B 0.62000 0 1 1 1 0 0 1 0 7 2 0.81500 0 1 0 0 1 1 0 0 4 C 0.62500 0 1 1 1 0 0 1 1 7 3 0.82000 0 1 0 0 1 1 0 1 4 D 0.63000 0 1 1 1 0 1 0 0 7 4 0.82500 7 6 5 4 3 2 1 0 0 0 1 0 0 1 1 1 2 0 0 1 0 1 0 0 0 0 0 1 0 1 0 0 0 0 1 0 1 0 0 0 1 0 1 0 0 1 0 0 0 1 0 0 0 13 HEX VO (V) FN8315.0 May 9, 2013 ISL95839 TABLE 1. VID TABLE (Continued) TABLE 1. VID TABLE (Continued) VID VID HEX VO (V) 7 6 5 4 3 2 1 0 5 0.83000 1 0 0 1 1 1 0 0 9 C 1.02500 7 6 0.83500 1 0 0 1 1 1 0 1 9 D 1.03000 1 7 7 0.84000 1 0 0 1 1 1 1 0 9 E 1.03500 0 0 7 8 0.84500 1 0 0 1 1 1 1 1 9 F 1.04000 0 0 1 7 9 0.85000 1 0 1 0 0 0 0 0 A 0 1.04500 1 0 1 0 7 A 0.85500 1 0 1 0 0 0 0 1 A 1 1.05000 1 1 0 1 1 7 B 0.86000 1 0 1 0 0 0 1 0 A 2 1.05500 1 1 1 1 0 0 7 C 0.86500 1 0 1 0 0 0 1 1 A 3 1.06000 1 1 1 1 1 0 1 7 D 0.87000 1 0 1 0 0 1 0 0 A 4 1.06500 0 1 1 1 1 1 1 0 7 E 0.87500 1 0 1 0 0 1 0 1 A 5 1.07000 0 1 1 1 1 1 1 1 7 F 0.88000 1 0 1 0 0 1 1 0 A 6 1.07500 1 0 0 0 0 0 0 0 8 0 0.88500 1 0 1 0 0 1 1 1 A 7 1.08000 1 0 0 0 0 0 0 1 8 1 0.89000 1 0 1 0 1 0 0 0 A 8 1.08500 1 0 0 0 0 0 1 0 8 2 0.89500 1 0 1 0 1 0 0 1 A 9 1.09000 1 0 0 0 0 0 1 1 8 3 0.90000 1 0 1 0 1 0 1 0 A A 1.09500 1 0 0 0 0 1 0 0 8 4 0.90500 1 0 1 0 1 0 1 1 A B 1.10000 1 0 0 0 0 1 0 1 8 5 0.91000 1 0 1 0 1 1 0 0 A C 1.10500 1 0 0 0 0 1 1 0 8 6 0.91500 1 0 1 0 1 1 0 1 A D 1.11000 1 0 0 0 0 1 1 1 8 7 0.92000 1 0 1 0 1 1 1 0 A E 1.11500 1 0 0 0 1 0 0 0 8 8 0.92500 1 0 1 0 1 1 1 1 A F 1.12000 1 0 0 0 1 0 0 1 8 9 0.93000 1 0 1 1 0 0 0 0 B 0 1.12500 1 0 0 0 1 0 1 0 8 A 0.93500 1 0 1 1 0 0 0 1 B 1 1.13000 1 0 0 0 1 0 1 1 8 B 0.94000 1 0 1 1 0 0 1 0 B 2 1.13500 1 0 0 0 1 1 0 0 8 C 0.94500 1 0 1 1 0 0 1 1 B 3 1.14000 1 0 0 0 1 1 0 1 8 D 0.95000 1 0 1 1 0 1 0 0 B 4 1.14500 1 0 0 0 1 1 1 0 8 E 0.95500 1 0 1 1 0 1 0 1 B 5 1.15000 1 0 0 0 1 1 1 1 8 F 0.96000 1 0 1 1 0 1 1 0 B 6 1.15500 1 0 0 1 0 0 0 0 9 0 0.96500 1 0 1 1 0 1 1 1 B 7 1.16000 1 0 0 1 0 0 0 1 9 1 0.97000 1 0 1 1 1 0 0 0 B 8 1.16500 1 0 0 1 0 0 1 0 9 2 0.97500 1 0 1 1 1 0 0 1 B 9 1.17000 1 0 0 1 0 0 1 1 9 3 0.98000 1 0 1 1 1 0 1 0 B A 1.17500 1 0 0 1 0 1 0 0 9 4 0.98500 1 0 1 1 1 0 1 1 B B 1.18000 1 0 0 1 0 1 0 1 9 5 0.99000 1 0 1 1 1 1 0 0 B C 1.18500 1 0 0 1 0 1 1 0 9 6 0.99500 1 0 1 1 1 1 0 1 B D 1.19000 1 0 0 1 0 1 1 1 9 7 1.00000 1 0 1 1 1 1 1 0 B E 1.19500 1 0 0 1 1 0 0 0 9 8 1.00500 1 0 1 1 1 1 1 1 B F 1.20000 1 0 0 1 1 0 0 1 9 9 1.01000 1 1 0 0 0 0 0 0 C 0 1.20500 1 0 0 1 1 0 1 0 9 A 1.01500 1 1 0 0 0 0 0 1 C 1 1.21000 1 0 0 1 1 0 1 1 9 B 1.02000 1 1 0 0 0 0 1 0 C 2 1.21500 7 6 5 4 3 2 1 0 0 1 1 1 0 1 0 1 7 0 1 1 1 0 1 1 0 0 1 1 1 0 1 1 0 1 1 1 1 0 0 1 1 1 1 0 1 1 1 0 1 1 0 1 0 14 HEX VO (V) FN8315.0 May 9, 2013 ISL95839 TABLE 1. VID TABLE (Continued) TABLE 1. VID TABLE (Continued) VID VID HEX VO (V) 7 6 5 4 3 2 1 0 3 1.22000 1 1 1 0 1 0 1 0 E A 1.41500 C 4 1.22500 1 1 1 0 1 0 1 1 E B 1.42000 1 C 5 1.23000 1 1 1 0 1 1 0 0 E C 1.42500 1 0 C 6 1.23500 1 1 1 0 1 1 0 1 E D 1.43000 1 1 1 C 7 1.24000 1 1 1 0 1 1 1 0 E E 1.43500 1 0 0 0 C 8 1.24500 1 1 1 0 1 1 1 1 E F 1.44000 0 1 0 0 1 C 9 1.25000 1 1 1 1 0 0 0 0 F 0 1.44500 0 0 1 0 1 0 C A 1.25500 1 1 1 1 0 0 0 1 F 1 1.45000 1 0 0 1 0 1 1 C B 1.26000 1 1 1 1 0 0 1 0 F 2 1.45500 1 1 0 0 1 1 0 0 C C 1.26500 1 1 1 1 0 0 1 1 F 3 1.46000 1 1 0 0 1 1 0 1 C D 1.27000 1 1 1 1 0 1 0 0 F 4 1.46500 1 1 0 0 1 1 1 0 C E 1.27500 1 1 1 1 0 1 0 1 F 5 1.47000 1 1 0 0 1 1 1 1 C F 1.28000 1 1 1 1 0 1 1 0 F 6 1.47500 1 1 0 1 0 0 0 0 D 0 1.28500 1 1 1 1 0 1 1 1 F 7 1.48000 1 1 0 1 0 0 0 1 D 1 1.29000 1 1 1 1 1 0 0 0 F 8 1.48500 1 1 0 1 0 0 1 0 D 2 1.29500 1 1 1 1 1 0 0 1 F 9 1.49000 1 1 0 1 0 0 1 1 D 3 1.30000 1 1 1 1 1 0 1 0 F A 1.49500 1 1 0 1 0 1 0 0 D 4 1.30500 1 1 1 1 1 0 1 1 F B 1.50000 1 1 0 1 0 1 0 1 D 5 1.31000 1 1 1 1 1 1 0 0 F C 1.50500 1 1 0 1 0 1 1 0 D 6 1.31500 1 1 1 1 1 1 0 1 F D 1.51000 1 1 0 1 0 1 1 1 D 7 1.32000 1 1 1 1 1 1 1 0 F E 1.51500 1 1 0 1 1 0 0 0 D 8 1.32500 1 1 1 1 1 1 1 1 F F 1.52000 1 1 0 1 1 0 0 1 D 9 1.33000 1 1 0 1 1 0 1 0 D A 1.33500 1 1 0 1 1 0 1 1 D B 1.34000 1 1 0 1 1 1 0 0 D C 1.34500 1 1 0 1 1 1 0 1 D D 1.35000 1 1 0 1 1 1 1 0 D E 1.35500 1 1 0 1 1 1 1 1 D F 1.36000 1 1 1 0 0 0 0 0 E 0 1.36500 7 6 5 4 3 2 1 0 1 1 0 0 0 0 1 1 C 1 1 0 0 0 1 0 0 1 1 0 0 0 1 0 1 1 0 0 0 1 1 1 0 0 0 1 1 0 0 1 1 0 1 1 1 1 1 0 0 0 0 1 E 1 1.37000 1 1 1 0 0 0 1 0 E 2 1.37500 VCCSENSE Vdroop FB VR LOCAL VO 1 1 0 0 0 1 1 E 3 1.38000 1 1 1 0 0 1 0 0 E 4 1.38500 1 1 1 0 0 1 0 1 E 5 1.39000 1 1 1 0 0 1 1 0 E 6 1.39500 1 1 1 0 0 1 1 1 E 7 1.40000 1 1 1 0 1 0 0 0 E 8 1.40500 1 1 1 0 1 0 0 1 E 9 1.41000 15 CATCH RESISTOR Idroop COMP Σ VIDs VID DAC VDAC RTN VSSSENSE INTERNAL TO IC 1 VO (V) Rdroop E/A 1 HEX X1 VSS CATCH RESISTOR FIGURE 10. DIFFERENTIAL SENSING AND LOAD LINE IMPLEMENTATION FN8315.0 May 9, 2013 ISL95839 As the load current increases from zero, the output voltage will droop from the VID table value by an amount proportional to the load current to achieve the load line. The controller can sense the inductor current through the intrinsic DC Resistance (DCR) of the inductors (as shown in Figure 3 on page 6) or through resistors in series with the inductors (as shown in Figure 4 on page 10). In both methods, capacitor Cn voltage represents the inductor total currents. A droop amplifier converts Cn voltage into an internal current source with the gain set by resistor Ri. The current source is used for load line implementation, current monitor and overcurrent protection. Figure 10 shows the load line implementation. The controller drives a current source Idroop out of the FB pin, described by Equation 1. V Cn I droop = ----------Ri Rewriting Equation 4 and substitution of Equation 2 gives: VCCSENSE – VSS SENSE = V DAC – R droop × I droop Equation 5 is the exact equation required for load line implementation. The VCCSENSE and VSSSENSE signals come from the processor die. The feedback will be open circuit in the absence of the processor. As Figure 10 shows, it is recommended to add a “catch” resistor to feed the VR local output voltage back to the compensator, and add another “catch” resistor to connect the VR local output ground to the RTN pin. These resistors, typically 10Ω~100Ω, will provide voltage feedback if the system is powered up without a processor installed. Phase Current Balancing (EQ. 1) When using inductor DCR current sensing, a single NTC element is used to compensate the positive temperature coefficient of the copper winding thus sustaining the load line accuracy with reduced cost. Idroop flows through resistor Rdroop and creates a voltage drop, as shown in Equation 2. V droop = R droop × I droop (EQ. 2) Vdroop is the droop voltage required to implement load line. Changing Rdroop or scaling Idroop can both change the load line slope. Since Idroop also sets the overcurrent protection level, it is recommended to first scale Idroop based on OCP requirement, then select an appropriate Rdroop value to obtain the desired load line slope. Current Monitor The controller provides the current monitor function. IMON and IMONG pin reports the inductor current for bothe VRs respectively. The IMON pin outputs a high-speed analog current source that is 1/4 of the droop current flowing out of the FB pin as Equation 3: (EQ. 5) Rdcr3 L3 ISEN3 Phase3 Risen Cisen INTERNAL TO IC ISEN2 ISEN1 IL3 L2 Phase2 Risen Cisen Phase1 Risen Rpcb3 Rdcr2 Rpcb2 Vo IL2 Rdcr1 L1 Rpcb1 IL1 Cisen FIGURE 11. CURRENT BALANCING CIRCUIT The controller monitors individual phase average current by monitoring the ISEN1, ISEN2, and ISEN3 voltages. Figure 11 shows the recommended current balancing circuit. Each phase node voltage is averaged by a low-pass filter consisting of Risen and Cisen, and presented to the corresponding ISEN pin. Risen should be routed to inductor phase-node pad in order to eliminate the effect of phase node parasitic PCB DCR. Equations 6 thru 8 give the ISEN pin voltages: (EQ. 3) V ISEN1 = ( R dcr1 + R pcb1 ) × I L1 (EQ. 6) A resistor Rimon is connected to the IMON pin to convert the IMON pin current to voltage. A capacitor should be paralleled with Rimon to filter the voltage information. V ISEN2 = ( R dcr2 + R pcb2 ) × I L2 (EQ. 7) V ISEN3 = ( R dcr3 + R pcb3 ) × I L3 (EQ. 8) I IMON = 0.25 × I droop The IMON pin voltage range is 0V to 1.2V. The controller monitors the IMON pin voltage and considers that ISL95839 has reached ICCMAX when IMON pin voltage is 1.2V. IMONG pin has the same operation principle as IMON pin. Differential Voltage Sensing Figure 10 also shows the differential voltage sensing scheme. VCCSENSE and VSSSENSE are the remote voltage sensing signals from the processor die. A unity gain differential amplifier senses the VSSSENSE voltage and adds it to the DAC output. The error amplifier regulates the inverting and the non-inverting input voltages to be equal, as shown in Equation 4: VCC SENSE + V droop = V DAC + VSS SENSE 16 (EQ. 4) where Rdcr1, Rdcr2 and Rdcr3 are inductor DCR; Rpcb1, Rpcb2 and Rpcb3 are parasitic PCB DCR between the inductor output side pad and the output voltage rail; and IL1, IL2 and IL3 are inductor average currents. The controller will adjust the phase pulse-width relative to the other phases to make VISEN1 = VISEN2 = VISEN3, thus to achieve IL1 = IL2 = IL3, when there are Rdcr1 = Rdcr2 = Rdcr3 and Rpcb1 = Rpcb2 = Rpcb3. Using the same components for L1, L2 and L3 will provide a good match of Rdcr1, Rdcr2 and Rdcr3. Board layout will determine Rpcb1, Rpcb2 and Rpcb3. It is recommended to have symmetrical layout for the power delivery path between each inductor and the output voltage rail, such that Rpcb1 = Rpcb2 = Rpcb3. FN8315.0 May 9, 2013 ISL95839 L3 V3p Rdcr3 The controller will make VISEN1 = VISEN2 = VISEN3, as shown in Equations 12 and 13: Rpcb3 Phase3 Risen ISEN3 Cisen INTERNAL TO IC ISEN2 Cisen IL3 Risen V3n Risen L2 V2p Phase2 Risen Rdcr2 IL2 Rpcb2 Vo (EQ. 12) V 1n + V 2p + V 3n = V 1n + V 2n + V 3p (EQ. 13) Rewriting Equation 12 gives Equation 14: V 1p – V 1n = V 2p – V 2n (EQ. 14) V2n Risen and rewriting Equation 13 gives Equation 15: Risen L1 Rdcr1 V1p V 2p – V 2n = V 3p – V 3n (EQ. 15) Rpcb1 Combining Equations 14 and 15 gives: Phase1 Risen ISEN1 Cisen V 1p + V 2n + V 3n = V 1n + V 2p + V 3n IL1 V 1p – V 1n = V 2p – V 2n = V 3p – V 3n V1n Risen (EQ. 16) Therefore: Risen FIGURE 12. DIFFERENTIAL-SENSING CURRENT BALANCING CIRCUIT Sometimes, it is difficult to implement symmetrical layout. For the circuit shown in Figure 11, asymmetric layout causes different Rpcb1, Rpcb2 and Rpcb3 thus current imbalance. Figure 12 shows a recommended differential-sensing current balancing circuit. The current sensing traces should be routed to the inductor pads so they only pick up the inductor DCR voltage. Each ISEN pin sees the average voltage of three sources: its own phase inductor phase-node pad, and the other two phases inductor output side pads. Equations 9 thru 11 give the ISEN pin voltages: V ISEN1 = V 1p + V 2n + V 3n (EQ. 9) V ISEN2 = V 1n + V 2p + V 3n (EQ. 10) V ISEN3 = V 1n + V 2n + V 3p (EQ. 11) 17 R dcr1 × I L1 = R dcr2 × I L2 = R dcr3 × I L3 (EQ. 17) Current balancing (IL1 = IL2 = IL3) will be achieved when there is Rdcr1 = Rdcr2 = Rdcr3. Rpcb1, Rpcb2 and Rpcb3 will not have any effect. Since the slave ripple capacitor voltages mimic the inductor currents, R3™ modulator can naturally achieve excellent current balancing during steady state and dynamic operations. Figure 13 shows current balancing performance of the evaluation board with load transient of 12A/51A at different rep rates. The inductor currents follow the load current dynamic change with the output capacitors supplying the difference. The inductor currents can track the load current well at low rep rate, but cannot keep up when the rep rate gets into the hundred-kHz range, where it’s out of the control loop bandwidth. The controller achieves excellent current balancing in all cases. FN8315.0 May 9, 2013 ISL95839 CCM Switching Frequency REP RATE = 10kHz REP RATE = 25kHz The resistor from COMPG and GND sets four different switching frequencies: 300kHz, 350kHz, 400kHz and 450kHz. Please refer to Table 8 on page 27 for details. To improve the efficiency at low VID, fixed on-time and period stretching will be implemented and CCM switching frequency will be proportional to the VID. The switching frequency will be stretched to 150kHz when VID = 0.25V. The VID starting to period stretching will be 0.5V*fSW_SET/300. For example, period stretching will start at VID = 0.5V with 300kHz switching frequency setting, and period stretching will start at VID = 0.75V with 450kHz switching frequency setting. Modes of Operation TABLE 2. VR1 MODES OF OPERATION PWM3 To External Driver ISEN2 To Power Stage CONFIG. 3-phase CPU VR Config. PS MODE OCP THRESHOLD (µA) 0 3-phase CCM 60 1 2-phase CCM 40 2 1-phase DE 20 3 REP RATE = 50kHz Tied to 5V 2-phase CPU VR Config. 0 2-phase CCM 60 1 1-phase CCM 30 2 1-phase DE 1-phase CPU VR Config. 0 3 Tied to 5V 1-phase CCM 60 1 2 1-phase DE 3 REP RATE = 100kHz VR1 can be configured for 3, 2 or 1-phase operation. Table 2 shows VR1 configurations and operational modes, programmed by the PWM3 pin and the ISEN2 pin status, and the PS command. For 2-phase configuration, tie the PWM3 pin to 5V. In this configuration, phases 1 and 2 are active. For 1-phase configuration, tie the PWM3 pin and the ISEN2 pin to 5V. In this configuration, only phase-1 is active. REP RATE = 200kHz In 3-phase configuration, VR1 operates in 3-phase CCM in PS0. It enters 2-phase CCM mode in PS1 by dropping phase 3 and reducing the overcurrent and the way-overcurrent protection levels to 2/3 of the initial values. It enters 1-phase DE mode in PS2 and PS3 by dropping phase 2, phase 3 and reducing the overcurrent and the way-overcurrent protection levels to 1/3 of the initial values. In 2-phase configuration, VR1 operates in 2-phase CCM in PS0. It enters 1-phase CCM mode in PS1, and enters 1-phase DE mode in PS2 and PS3 by dropping phase 2, and reducing the overcurrent and the way-overcurrent protection levels to 1/2 of the initial values. FIGURE 13. CURRENT BALANCING DURING DYNAMIC OPERATION. CH1: IL1, CH2: ILOAD, CH3: IL2, CH4: IL3 18 In 1-phase configuration, VR1 operates in 1-phase CCM in PS0 and PS1, and enters 1-phase DE mode in PS2 and PS3. FN8315.0 May 9, 2013 ISL95839 Table 3 shows VR2 operational modes, programmed by the PS command. VR2 operates in CCM in PS0 and PS1, and enters DE mode in PS2 and PS3. VR2 can be disabled completely by tying ISUMNG to 5V, and all communication to VR2 will be rejected. TABLE 3. VR2 MODES OF OPERATION PS 0 OCP THRESHOLD (µA) MODE 1-phase CCM VR_HOT#/ALERT# Behavior VR Temperature Temp Zone Bit 7 =1 7 1 Bit 6 =1 3% Hysteris 1111 1111 10 0111 1111 0011 1111 Bit 5 =1 12 60 1 2 The R3™ modulator intrinsically has voltage feed-forward. The output voltage is insensitive to a fast slew rate input voltage change. 0001 1111 Temp Zone Register 2 8 0001 1111 0011 1111 0111 1111 1111 1111 0111 1111 0011 1111 0001 1111 Status 1 3 = “011” = “001” Register = “001” 1-phase DE 3 Dynamic Operation VR1 and VR2 behave the same during dynamic operation. The controller responds to VID changes by slewing to the new voltage at a slew rate indicated in the SetVID command. There are three SetVID slew rates, namely SetVID_fast, SetVID_slow and SetVID_decay. SetVID_fast command prompts the controller to enter CCM and to actively drive the output voltage to the new VID value at a minimum 10mV/µs slew rate. SetVID_slow command prompts the controller to enter CCM and to actively drive the output voltage to the new VID value at a minimum 2.5mV/µs slew rate. S e tV ID _ d e c a y S e tV ID _ fa s t/s lo w Vo GerReg Status1 SVID ALERT# 4 VR_HOT# 5 13 6 14 9 GerReg Status1 15 16 11 FIGURE 15. VR_HOT#/ALERT# BEHAVIOR The controller drives 60µA current source out of the NTC pin and the NTCG pin alternatively at approximately 36kHz frequency with 50% duty cycle. The current source flows through the respective NTC resistor networks on the pins and creates voltages that are monitored by the controller through an A/D converter (ADC) to generate the TZONE value. Table 4 shows the programming table for TZONE. The user needs to scale the NTC and the NTCG network resistance such that it generates the NTC (and NTCG) pin voltage that corresponds to the left-most column. Do not use any capacitor to filter the voltage. TABLE 4. TZONE TABLE V ID t3 t1 T _ a le r t t2 ALERT# FIGURE 14. SETVID DECAY PRE-EMPTIVE BEHAVIOR SetVID_decay command prompts the controller to enter DE mode. The output voltage will decay down to the new VID value at a slew rate determined by the load. If the voltage decay rate is too fast, the controller will limit the voltage slew rate at 10mV/µs. ALERT# will be asserted low at the end of SetVID_fast and SetVID_slow VID transitions. Figure 14 shows SetVID Decay Pre-Emptive behavior. The controller receives a SetVID_decay command at t1. The VR enters DE mode and the output voltage Vo decays down slowly. At t2, before Vo reaches the intended VID target of the SetVID_decay command, the controller receives a SetVID_fast (or SetVID_slow) command to go to a voltage higher than the actual Vo. The controller will turn around immediately and slew Vo to the new target voltage at the slew rate specified by the SetVID command. At t3, Vo reaches the new target voltage and the controller asserts the ALERT# signal. VNTC (V) TMAX (%) TZONE 0.84 >100 FFh 0.88 100 FFh 0.92 97 7Fh 0.96 94 3Fh 1.00 91 1Fh 1.04 88 0Fh 1.08 85 07h 1.12 82 03h 1.16 79 01h 1.2 76 01h >1.2 <76 00h Figure 15 shows how the NTC and the NTCG network should be designed to get correct VR_HOT#/ALERT# behavior when the system temperature rises and falls, manifested as the NTC and the NTCG pin voltage falls and rises. The series of events are: 1. The temperature rises so the NTC pin (or the NTCG pin) voltage drops. TZONE value changes accordingly. 2. The temperature crosses the threshold where TZONE register Bit 6 changes from 0 to 1. 3. The controller changes Status_1 register bit 1 from 0 to 1. 19 FN8315.0 May 9, 2013 ISL95839 4. The controller asserts ALERT#. 5. The CPU reads Status_1 register value to know that the alert assertion is due to TZONE register Bit 6 flipping. Adaptive Body Diode Conduction Time Reduction 14. The controller asserts ALERT#. In DCM, the controller turns off the low-side MOSFET when the inductor current approaches zero. During on-time of the low-side MOSFET, phase voltage is negative and the amount is the MOSFET rDS(ON) voltage drop, which is proportional to the inductor current. A phase comparator inside the controller monitors the phase voltage during on-time of the low-side MOSFET and compares it with a threshold to determine the zero-crossing point of the inductor current. If the inductor current has not reached zero when the low-side MOSFET turns off, it’ll flow through the low-side MOSFET body diode, causing the phase node to have a larger voltage drop until it decays to zero. If the inductor current has crossed zero and reversed the direction when the low-side MOSFET turns off, it’ll flow through the high-side MOSFET body diode, causing the phase node to have a spike until it decays to zero. The controller continues monitoring the phase voltage after turning off the low-side MOSFET and adjusts the phase comparator threshold voltage accordingly in iterative steps such that the low-side MOSFET body diode conducts for approximately 40ns to minimize the body diode-related loss. 15. The CPU reads Status_1 register value to know that the alert assertion is due to TZONE register Bit 5 flipping. Protections 6. The controller clears ALERT#. 7. The temperature continues rising. 8. The temperature crosses the threshold where TZONE register Bit 7 changes from 0 to 1. 9. The controllers asserts VR_HOT# signal. The CPU throttles back and the system temperature starts dropping eventually. 10. The temperature crosses the threshold where TZONE register Bit 6 changes from 1 to 0. This threshold is 1 ADC step lower than the one when VR_HOT# gets asserted, to provide 3% hysteresis. 11. The controllers de-asserts VR_HOT# signal. 12. The temperature crosses the threshold where TZONE register Bit 5 changes from 1 to 0. This threshold is 1 ADC step lower than the one when ALERT# gets asserted during the temperature rise to provide 3% hysteresis. 13. The controller changes Status_1 register bit 1 from 1 to 0. 16. The controller clears ALERT#. FB2 Function C1 R2 CONTROLLER IN 3- AND 2-PHASE MODE C2 R3 C1 R2 CONTROLLER IN 1-PHASE MODE C3.1 The controller determines overcurrent protection (OCP) by comparing the average value of the droop current Idroop with an internal current source threshold as Table 2 shows. It declares OCP when Idroop is above the threshold for 120µs. C3.1 C2 R3 C3.2 FB2 R1 FB2 C3.2 R1 VSEN VSEN E/A FB VREF FB COMP VREF E/A COMP FIGURE 16. FB2 FUNCTION Figure 16 shows the FB2 function. A switch (called FB2 switch) turns on to short the FB and the FB2 pins when the controller is in 2-phase mode. Capacitors C3.1 and C3.2 are in parallel, serving as part of the compensator. When the controller enters 1-phase mode, the FB2 switch turns off, removing C3.2 and leaving only C3.1 in the compensator. The compensator gain will increase with the removal of C3.2. By properly sizing C3.1 and C3.2, the compensator can be optimal for both 3-, 2-phase mode and 1-phase mode. When the FB2 switch is off, C3.2 is disconnected from the FB pin. However, the controller still actively drives the FB2 pin voltage to follow the FB pin voltage such that C3.2 voltage always follows C3.1 voltage. When the controller turns on the FB2 switch, C3.2 will be reconnected to the compensator smoothly. The FB2 function ensures excellent transient response in both 3-, 2-phase mode and 1-phase mode. If one decides not to use the FB2 function, simply populate C3.1 only. 20 VR1 and VR2 both provide overcurrent, current-balance and overvoltage fault protections. The controller also provides over-temperature protection. The following discussion is based on VR1 and also applies to VR2. For overcurrent conditions above 1.5x the OCP level, the PWM outputs will immediately shut off and PGOOD will go low to maximize protection. This protection is also referred to as way-overcurrent protection or fast-overcurrent protection, for short-circuit protection. The controller monitors the ISEN pin voltages to determine current-balance protection. If the difference of one ISEN pin voltage and the average ISENs pin voltage is greater than 9mV for at least 3.2ms, the controller will declare a fault and latch off. The controller takes the same actions for all of the above fault protections: de-assertion of both PGOODs and turn-off of all the high-side and low-side power MOSFETs. Any residual inductor current will decay through the MOSFET body diodes. The controller will declare an overvoltage fault and de-assert PGOOD if the output voltage exceeds the VID set value by +200mV. The controller will immediately declare an OV fault, de-assert PGOOD, and turn on the low-side power MOSFETs. The low-side power MOSFETs remain on until the output voltage is pulled down below the VID set value when all power MOSFETs are turned off. If the output voltage rises above the VID set value +200mV again, the protection process is repeated. This behavior provides the maximum amount of protection against shorted high-side power MOSFETs while preventing output ringing below ground. FN8315.0 May 9, 2013 ISL95839 The overvoltage fault threshold is 1.7V when output voltage ramps up from 0V. And the overvoltage fault threshold is restored to VID set value + 200mV after the output voltage settles. All the above fault conditions can be reset by bringing VR_ON low or by bringing VDD below the POR threshold. When VR_ON and VDD return to their high operating levels, a soft-start will occur. TABLE 6. SUPPORTED DATA AND CONFIGURATION REGISTERS (Continued) INDEX REGISTER NAME ICC max Data register containing the ICC max Refer to the platform supports, set at start-up by Table 7 resistors Rprog1 and Rprog2. The platform design engineer programs this value during the design process. Binary format in amps, i.e., 100A = 64h 22h Temp max Not supported 24h SR-fast Slew Rate Normal. The fastest slew rate 0Ah the platform VR can sustain. Binary format in mV/µs. i.e., 0Ah = 10mV/µs. 25h SR-slow Is 4x slower than normal. Binary format 02h in mV/µs. i.e., 02h = 2.5mV/µs 26h VBOOT If programmed by the platform, the VR 00h supports VBOOT voltage during start-up ramp. The VR will ramp to VBOOT and hold at VBOOT until it receives a new SetVID command to move to a different voltage. 30h Vout max FBh This register is programmed by the master and sets the maximum VID the VR will support. If a higher VID code is received, the VR will respond with “not supported” acknowledge. 31h VID Setting Data register containing currently programmed VID voltage. VID data format. DEFAULT VALUE 32h Power State Register containing the current programmed power state. 33h Voltage Offset 00h Sets offset in VID steps added to the VID setting for voltage margining. Bit 7 is a sign bit, 0 = positive margin, 1 = negative margin. Remaining 7 bits are # VID steps for the margin. 00h = no margin, 01h = +1 VID step 02h = +2 VID steps... 34h Multi VR Config Data register that configures multiple VRs behavior on the same SVID bus. TABLE 5. FAULT PROTECTION SUMMARY FAULT TYPE Overcurrent 120µs Phase Current Unbalance 3.2ms Way-Overcurrent (1.5xOC) PROTECTION ACTION PWM tri-state, PGOOD latched low FAULT RESET VR_ON toggle or VDD toggle Immediately Overvoltage +200mV PGOOD latched low. Actively pulls the output voltage to below VID value, then tri-state. 1.7V overvoltage during output voltage ramp up from 0V Supported Data and Configuration Registers The controller supports the following data and configuration registers. TABLE 6. SUPPORTED DATA AND CONFIGURATION REGISTERS INDEX REGISTER NAME DESCRIPTION 00h Vendor ID Uniquely identifies the VR vendor. Assigned by Intel. 12h 01h Product ID Uniquely identifies the VR product. Intersil assigns this number. 24h 02h Product Revision Uniquely identifies the revision of the VR control IC. Intersil assigns this data. 05h Protocol ID Identifies what revision of SVID protocol 01h the controller supports. 06h Capability Identifies the SVID VR capabilities and 81h which of the optional telemetry registers are supported. 10h Status_1 Data register read after ALERT# signal. 00h Indicating if a VR rail has settled, has reached VRHOT condition or has reached ICC max. 11h Status_2 Data register showing status_2 communication. 12h Temperature Data register showing temperature Zone zones that have been entered. 00h 1Ch Status_2_ LastRead 00h This register contains a copy of the Status_2 data that was last read with the GetReg (Status_2) command. 21 DEFAULT VALUE 21h Table 5 summarizes the fault protections. FAULT DURATION BEFORE PROTECTION DESCRIPTION 00h 00h VR1: 00h VR2: 01h 00h FN8315.0 May 9, 2013 ISL95839 Key Component Selection 1 ω sns = -------------------------------------------------------R sum R ntcnet × --------------N ------------------------------------------ × C n R sum R ntcnet + --------------N Inductor DCR Current-Sensing Network Phase1 Phase2 Phase3 Rsum where N is the number of phases. Rsum ISUM+ Rsum L L L Rntcs Rp DCR DCR DCR Cn Vcn Rntc Ro Ri ISUM- Ro Ro Io FIGURE 17. DCR CURRENT-SENSING NETWORK Figure 17 shows the inductor DCR current-sensing network for a 3-phase solution. An inductor current flows through the DCR and creates a voltage drop. Each inductor has two resistors in Rsum and Ro connected to the pads to accurately sense the inductor current by sensing the DCR voltage drop. The Rsum and Ro resistors are connected in a summing network as shown, and feed the total current information to the NTC network (consisting of Rntcs, Rntc and Rp) and capacitor Cn. Rntc is a negative temperature coefficient (NTC) thermistor, used to temperature-compensate the inductor DCR change. The inductor output side pads are electrically shorted in the schematic, but have some parasitic impedance in actual board layout, which is why one cannot simply short them together for the current-sensing summing network. It is recommended to use 1Ω~10Ω Ro to create quality signals. Since Ro value is much smaller than the rest of the current sensing circuit, the following analysis will ignore it for simplicity. The summed inductor current information is presented to the capacitor Cn. Equations 18 thru 22 describe the frequency-domain relationship between inductor total current Io(s) and Cn voltage VCn(s): ⎛ ⎞ R ntcnet ⎜ DCR⎟ V Cn ( s ) = ⎜ ------------------------------------------ × -------------⎟ × I o ( s ) × A cs ( s ) R sum N ⎟ ⎜ ⎝ R ntcnet + -------------⎠ N (EQ. 18) ( R ntcs + R ntc ) × R p R ntcnet = ---------------------------------------------------R ntcs + R ntc + R p (EQ. 19) s 1 + ------ωL A cs ( s ) = ----------------------s 1 + ------------ω sns (EQ. 20) DCR ω L = ------------L (EQ. 21) 22 (EQ. 22) Transfer function Acs(s) always has unity gain at DC. The inductor DCR value increases as the winding temperature increases, giving higher reading of the inductor DC current. The NTC Rntc values decrease as its temperature decreases. Proper selections of Rsum, Rntcs, Rp and Rntc parameters ensure that VCn represent the inductor total DC current over the temperature range of interest. There are many sets of parameters that can properly temperature-compensate the DCR change. Since the NTC network and the Rsum resistors form a voltage divider, Vcn is always a fraction of the inductor DCR voltage. It is recommended to have a higher ratio of Vcn to the inductor DCR voltage, so the droop circuit has a higher signal level to work with. A typical set of parameters that provide good temperature compensation are: Rsum = 3.65kΩ, Rp = 11kΩ, Rntcs = 2.61kΩ and Rntc = 10kΩ (ERT-J1VR103J). The NTC network parameters may need to be fine tuned on actual boards. One can apply full load DC current and record the output voltage reading immediately; then record the output voltage reading again when the board has reached the thermal steady state. A good NTC network can limit the output voltage drift to within 2mV. It is recommended to follow the Intersil evaluation board layout and current-sensing network parameters to minimize engineering time. VCn(s) also needs to represent real-time Io(s) for the controller to achieve good transient response. Transfer function Acs(s) has a pole wsns and a zero wL. One needs to match wL and wsns so Acs(s) is unity gain at all frequencies. By forcing wL equal to wsns and solving for the solution, Equation 23 gives the Cn value. L C n = --------------------------------------------------------------R sum R ntcnet × --------------N -----------------------------------------× DCR R sum R ntcnet + --------------N (EQ. 23) For example, given N = 3, Rsum = 3.65kΩ, Rp = 11kΩ, Rntcs = 2.61kΩ, Rntc = 10kΩ, DCR = 0.9mΩ and L = 0.36µH, Equation 23 gives Cn = 0.397µF. Assuming the compensator design is correct, Figure 18 shows the expected load transient response waveforms if Cn is correctly selected. When the load current Icore has a square change, the output voltage Vcore also has a square response. If Cn value is too large or too small, VCn(s) will not accurately represent real-time Io(s) and will worsen the transient response. Figure 19 shows the load transient response when Cn is too small. Vcore will sag excessively upon load insertion and may create a system failure. Figure 20 shows the transient response when Cn is too large. Vcore is sluggish in drooping to its final value. There will be excessive overshoot if load insertion occurs during this time, which may potentially hurt the CPU reliability. FN8315.0 May 9, 2013 ISL95839 ISUM+ io Rntcs Vo Cn.1 Cn.2 Vcn Rp Rntc FIGURE 18. DESIRED LOAD TRANSIENT RESPONSE WAVEFORMS Rn OPTIONAL Rip io ISUM- Ri Cip OPTIONAL FIGURE 22. OPTIONAL CIRCUITS FOR RING BACK REDUCTION Vo FIGURE 19. LOAD TRANSIENT RESPONSE WHEN Cn IS TOO SMALL io Figure 22 shows two optional circuits for reduction of the ring back. Vo FIGURE 20. LOAD TRANSIENT RESPONSE WHEN Cn IS TOO LARGE io Figure 21 shows the output voltage ring back problem during load transient response. The load current io has a fast step change, but the inductor current iL cannot accurately follow. Instead, iL responds in first order system fashion due to the nature of current loop. The ESR and ESL effect of the output capacitors makes the output voltage Vo dip quickly upon load current change. However, the controller regulates Vo according to the droop current idroop, which is a real-time representation of iL; therefore it pulls Vo back to the level dictated by iL, causing the ring back problem. This phenomenon is not observed when the output capacitor have very low ESR and ESL, such as all ceramic capacitors. iL Vo RING BACK FIGURE 21. OUTPUT VOLTAGE RING BACK PROBLEM Cn is the capacitor used to match the inductor time constant. It usually takes the parallel of two (or more) capacitors to get the desired value. Figure 22 shows that two capacitors Cn.1 and Cn.2 are in parallel. Resistor Rn is an optional component to reduce the Vo ring back. At steady state, Cn.1 + Cn.2 provides the desired Cn capacitance. At the beginning of io change, the effective capacitance is less because Rn increases the impedance of the Cn.1 branch. As Figure 19 explains, Vo tends to dip when Cn is too small, and this effect will reduce the Vo ring back. This effect is more pronounced when Cn.1 is much larger than Cn.2. It is also more pronounced when Rn is bigger. However, the presence of Rn increases the ripple of the Vn signal if Cn.2 is too small. It is recommended to keep Cn.2 greater than 2200pF. Rn value usually is a few ohms. Cn.1, Cn.2 and Rn values should be determined through tuning the load transient response waveforms on an actual board. Rip and Cip form an R-C branch in parallel with Ri, providing a lower impedance path than Ri at the beginning of io change. Rip and Cip do not have any effect at steady state. Through proper selection of Rip and Cip values, idroop can resemble io rather than iL, and Vo will not ring back. The recommended value for Rip is 100Ω. Cip should be determined through tuning the load transient response waveforms on an actual board. The recommended range for Cip is 100pF~2000pF. However, it should be noted that the Rip -Cip branch may distort the idroop waveform. Instead of being triangular as the real inductor 23 FN8315.0 May 9, 2013 ISL95839 current, idroop may have sharp spikes, which may adversely affect idroop average value detection and therefore may affect OCP accuracy. User discretion is advised. Resistor Current-Sensing Network Phase1 Phase2 Phase3 L L L DCR DCR DCR ⎛ ⎞ R ntcnet ⎜ DCR⎟ V Cn = ⎜ ------------------------------------------ × -------------⎟ × I o R sum N ⎟ ⎜ ⎝ R ntcnet + -------------⎠ N (EQ. 27) Substitution of Equation 27 into Equation 1 gives Equation 28: R ntcnet DCR 1 I droop = ----- × ------------------------------------------ × ------------- × I o N R sum Ri R ntcnet + --------------N (EQ. 28) Therefore: R ntcnet × DCR × I o R i = ---------------------------------------------------------------------------------R sum N × ⎛ R ntcnet + ---------------⎞ × I droop ⎝ N ⎠ Rsum Rsum ISUM+ Rsum Rsen Rsen Rsen Vcn Ro Cn Ri ISUM- Ro Ro Io FIGURE 23. RESISTOR CURRENT-SENSING NETWORK Figure 23 shows the resistor current-sensing network for a 2-phase solution. Each inductor has a series current-sensing resistor Rsen. Rsum and Ro are connected to the Rsen pads to accurately capture the inductor current information. The Rsum and Ro resistors are connected to capacitor Cn. Rsum and Cn form a filter for noise attenuation. Equations 24 thru 26 give VCn(s) expression: R sen V Cn ( s ) = ------------- × I o ( s ) × A Rsen ( s ) N 1 A Rsen ( s ) = --------------------------s 1 + ----------------ω Rsen (EQ. 24) (EQ. 25) (EQ. 29) Substitution of Equation 19 and application of the OCP condition in Equation 29 gives Equation 30: ( R ntcs + R ntc ) × R p ---------------------------------------------------- × DCR × I omax R ntcs + R ntc + R p R i = ----------------------------------------------------------------------------------------------------------------------------⎛ ( R ntcs + R ntc ) × R p R sum⎞ N × ⎜ ---------------------------------------------------- + ---------------⎟ × I droopmax N ⎠ ⎝ R ntcs + R ntc + R p (EQ. 30) where Iomax is the full load current, Idroopmax is the corresponding droop current. For example, given N = 3, Rsum = 3.65kΩ, Rp = 11kΩ, Rntcs = 2.61kΩ, Rntc = 10kΩ, DCR = 0.9mΩ, Iomax = 94A and Idroopmax = 50µA, Equation 30 gives Ri = 467Ω. For resistor sensing, Equation 31 gives the DC relationship of Vcn(s) and Io(s). R sen V Cn = ------------- × I o N (EQ. 31) Substitution of Equation 31 into Equation 1 gives Equation 32: 1 R sen I droop = ----- × ------------- × I o N Ri (EQ. 32) Therefore: 1 ω Rsen = ----------------------------R sum --------------- × C n N (EQ. 26) Transfer function ARsen(s) always has unity gain at DC. Current-sensing resistor Rsen value will not have significant variation over-temperature, so there is no need for the NTC network. The recommended values are Rsum = 1kΩ and Cn = 5600pF. Overcurrent Protection Refer to Equation 1 on page 16 and Figures 17, 21 and 23; resistor Ri sets the droop current Idroop. Tables 2 and 3 show the internal OCP threshold. It is recommended to design Idroop without using the RCOMP resistor. For example, the OCP threshold is 60µA for 3-phase solution. We will design Idroop to be 50µA at full load, so the OCP trip level is 1.2x of the full load current. For inductor DCR sensing, Equation 27 gives the DC relationship of Vcn(s) and Io(s). 24 R sen × I o R i = --------------------------N × I droop (EQ. 33) Substitution of Equation 33 and application of the OCP condition in Equation 29 gives Equation 34: R sen × I omax R i = -------------------------------------N × I droopmax (EQ. 34) where Iomax is the full load current, Idroopmax is the corresponding droop current. For example, given N = 3, Rsen = 1mΩ, Iomax = 94A and Idroopmax = 50µA, Equation 34 gives Ri = 627Ω. Load Line Slope Refer to Figure 10. For inductor DCR sensing, substitution of Equation 28 into Equation 2 gives the load line slope expression: R droop R ntcnet V droop DCR LL = ------------------- = ------------------- × ------------------------------------------ × ------------Io Ri R sum N R ntcnet + --------------N (EQ. 35) FN8315.0 May 9, 2013 ISL95839 For resistor sensing, substitution of Equation 32 into Equation 2 gives the load line slope expression: R sen × R droop V droop LL = ------------------- = --------------------------------------N × Ri Io (EQ. 36) Substitution of Equation 29 and rewriting Equation 35, or substitution of Equation 33 and rewriting Equation 36 give the same result in Equation 37: Io R droop = ---------------- × LL I droop T1(s) is the total loop gain of the voltage loop and the droop loop. It always has a higher crossover frequency than T2(s) and has more meaning of system stability. T2(s) is the voltage loop gain with closed droop loop. It has more meaning of output voltage response. Design the compensator to get stable T1(s) and T2(s) with sufficient phase margin, and output impedance equal or smaller than the load line slope. (EQ. 37) Q1 GATE Q2 DRIVER Vin It is recommended to start with the Rdroop value calculated by Equation 37, and fine tune it on the actual board to get accurate load line slope. One should record the output voltage readings at no load and at full load for load line slope calculation. Reading the output voltage at lighter load instead of full load will increase the measurement error. LOAD LINE SLOPE 20W Ω EA MOD. COMP VID ISOLATION TRANSFORMER CHANNEL B LOOP GAIN = CHANNEL A Figure 18 shows the desired load transient response waveforms. Figure 24 shows the equivalent circuit of a voltage regulator (VR) with the droop function. A VR is equivalent to a voltage source (= VID) and output impedance Zout(s). If Zout(s) is equal to the load line slope LL, i.e., constant output impedance, in the entire frequency range, Vo will have square response when Io has a square change. i io Cout Compensator Zout(s) = LL Vo L One can use the full load condition to calculate Rdroop. For example, given Iomax = 94A, Idroopmax = 50µA and LL = 1.9mΩ, Equation 37 gives Rdroop = 3.57kΩ. CHANNEL A CHANNEL B NETWORK ANALYZER EXCITATION OUTPUT FIGURE 25. LOOP GAIN T1(s) MEASUREMENT SET-UP o VO L Q1 VID VR LOAD V o VIN GATE Q2 DRIVER COUT I O LOAD LINE SLOPE 20 Ω FIGURE 24. VOLTAGE REGULATOR EQUIVALENT CIRCUIT Intersil provides a Microsoft Excel-based spreadsheet to help design the compensator and the current sensing network, so the VR achieves constant output impedance as a stable system. Please go to http://www.intersil.com/en/support.html to request spreadsheet. A VR with active droop function is a dual-loop system consisting of a voltage loop and a droop loop which is a current loop. However, neither loop alone is sufficient to describe the entire system. The spreadsheet shows two loop gain transfer functions, T1(s) and T2(s), that describe the entire system. Figure 25 conceptually shows T1(s) measurement set-up and Figure 26 conceptually shows T2(s) measurement set-up. The VR senses the inductor current, multiplies it by a gain of the load line slope, then adds it on top of the sensed output voltage and feeds it to the compensator. T(1) is measured after the summing node, and T2(s) is measured in the voltage loop before the summing node. The spreadsheet gives both T1(s) and T2(s) plots. However, only T2(s) can be actually measured on an ISL95839 regulator. 25 EA MOD. COMP CHANNEL B LOOP GAIN = CHANNEL A VID ISOLATION TRANSFORMER CHANNEL A CHANNEL B NETWORK ANALYZER EXCITATION OUTPUT FIGURE 26. LOOP GAIN T2(s) MEASUREMENT SET-UP FN8315.0 May 9, 2013 Compensation & Current Sensing Network Design for Intersil Multiphase R^3 Regulators. 26 Revision 9.1 Attention: 1. "Analysis ToolPak" Add-in is required. (To turn it on in MS Excel 2003, go to Tools--Add-Ins, and check "Analysis ToolPak"). 2. Green cells require user input Compensator Parameters C3 Operation Parameters Controller Part Number: IS ISL95839 L95836 § s · § s · C2 R3 C1 R2 ¸ ¨1 ¸ KZi Zi ¨¨1 Phase Number: 3 2Sf z1 ¸¹ ¨© 2Sf z 2 ¸¹ © AV ( s ) Vin: 12 volts § · § · R1 s s FB ¸ ¨1 ¸ Vo: 1 volts s ¨1 COMP ¨ 2Sf p1 ¸¹ ¨© 2Sf p 2 ¸¹ OPAMP © Full Load Current: 94 Amps Vref Rcomp Estimated Full-Load Efficiency: 85 % Number of Output Bulk Capacitors: 4 Recommended Value User-Selected Value Capacitance of Each Output Bulk Capacitor: 470 uF R1 3.572 k : R1 3.57 k : ESR of Each Output Bulk Capacitor: 4.5 m : ESL of Each Output Bulk Capacitor: 0.2 nH R2 270.237 k : R2 267 k : Number of Output Ceramic Capacitors: 28 R3 0.699 k : R3 0.499 k : Capacitance of Each Output Ceramic Capacitor: 10 uF C1 497.168 pF C1 150 pF C2 505.690 pF C2 470 pF ESR of Each Output Ceramic Capacitor: 3 m: ESL of Each Output Ceramic Capacitor: 3 nH C3 31.478 pF C3 47 pF Switching Frequency: 300 kHz Rcomp 274 k : Y Use User-Selected Value (Y/N)? Inductance Per Phase: 0.36 uH Disable Droop Function (Y/N)? N CPU Socket Resistance: 0.9 m : Performance and Stability Desired Load-Line Slope: 1.9 m : Desired Idroop Current at Full Load: 50 uA T1 Bandwidth: 118kHz T2 Bandwidth: 38kHz (This sets the over-current protection level) T1 Phase Margin: 74.1° T2 Phase Margin: 85.9° Current Sensing Network Parameters Phase1 Phase2 Rsum Rsum L L DCR DCR 7V 0DJQLWXGHPRKP ( ( ( ( ( ( Ro Do The Following For Resistor Operation Parameters Sensing <-- Rsense Inductor DCR 0.9 m : Rsum 3.65 k : <-- 0.001k Rntc 10 k : <-- 1000k Rntcs 2.61 k : <-- 1000k Rp 11 k : <-- 1000k Vo These Rsum and Cn values are used to "fool" the spreadsheet so it can calculate for resistor-sensing application They should not be used on the actual schematics COMP Pin Voltage During Reading of Rcomp Value (Only On Controllers With COMP Pin Resistor Reader Function) ( ( ( ( ( ( ( ( Loop Gain, Phase Curve 7V 7V 3KDVHGHJUHH 3KDVHGHJUHH Recommended Value Copy To User Selected Value -------> Cn 0.397 uF Cn 0.397 uF Ri 467 : Ri 467.239 : )UHTXHQF\+] Output Impedance Z(f), Phase Curve Voltage Threshold COMP Pin Voltage ( ( ( ( )UHTXHQF\+] ( ( ( 7LPHPV ( Output Impedance Z(f), Gain Curve )UHTXHQF\+] ISUM- Ri Ro ( DCR Ro &2033LQ9ROWDJH9 *DLQG% 7V Cn RNTC ( ( ( ( ( ( ( ( )UHTXHQF\+] Note: COMP pin voltage needs to reach or cross the threshold voltage at "Time"=1ms. The above COMP pin waveform passes FN8315.0 May 9, 2013 FIGURE 27. SCREENSHOT OF THE COMPENSATOR DESIGN SPREADSHEET ISL95839 ( RNTCS L Rp 1.3 Loop Gain, Gain Curve ISUM+ Rsum Changing the settings in red requires deep understanding of control loop design Place the 2nd compensator pole fp2 at: 1.5 xfs (Switching Frequency) 7XQH.ȦLWRJHWWKHGHVLUHGORRSJDLQEDQGZLGWK Tune the compensator gain factor KȦi: 5HFRPPHQGHG.ȦLUDQJHLVa Phase3 ISL95839 Programming Resistors TABLE 8. RCOMPG PROGRAMMING TABLE There are two programming resistors: RCOMP and RCOMPG. Table 7 shows how to select RCOMP based on VBOOT and VR1 ICCMAX register settings. VR1 can power to 0V VBOOT or an internally-set VBOOT based on RCOMP value. When the controller works with an actual CPU, select RCOMP such that VR1 powers up to VBOOT = 0V as required by the SVID command. In the absence of a CPU, such as testing of the VR alone, select RCOMP such that VR1 powers up to the internally-set VBOOT, which by default is 1.1V. Determine the maximum current VR1 can support and set the VR1 ICCMAX register value accordingly by selecting the appropriate RCOMP value. The CPU will read the VR1 ICCMAX register value and ensure that the CPU CORE current doesn’t exceed the value specified by VR1 ICCMAX. Table 8 shows how to select RCOMPG based on VR1 and VR2 CCM switching frequency and VR2 ICCMAX register settings. There are four switching frequencies to choose from: 300kHz, 350kHz, 400kHz, and 450kHz. There are also three VR2 ICCMAX values to choose. TABLE 7. RCOMP PROGRAMMING TABLE RCOMP (kΩ) RCOMPG (kΩ) MIN TYP MAX SWITCHING FREQUENCY (kHz) VR2 ICCMAX (A) 12.0 13.2 14.4 450 33 15.8 17.0 18.2 450 24 19.6 20.8 22.0 450 18 23.4 24.6 25.8 400 18 27.2 28.4 29.6 400 24 31.2 33.7 36.1 400 33 86.2 88.9 91.6 350 33 97.3 100.3 103.3 350 24 108.3 111.7 115.1 350 18 119.5 123.2 126.8 300 18 132.5 136.6 140.6 300 24 147.2 151.8 156.3 300 33 Current Balancing MIN TYP MAX VBOOT (V) VR1 ICCMAX (A) 2.7 2.85 3.0 0 99 5.0 5.6 6.2 0 94 8.4 9.4 10.4 0 80 12.0 13.2 14.4 0 70 15.8 17.0 18.2 0 60 19.6 20.8 22.0 0 53 23.4 24.6 25.8 0 48 27.2 28.4 29.6 0 43 31.2 33.7 36.1 0 38 38.8 41.3 43.7 0 33 46.4 48.9 51.3 0 24 54.0 56.5 58.9 0 18 62.1 64.1 66.0 1.1 18 69.5 71.7 73.8 1.1 24 76.9 79.3 81.7 1.1 33 86.2 88.9 91.6 1.1 38 97.3 100.3 103.3 1.1 43 108.3 111.7 115.1 1.1 48 119.5 123.2 126.8 1.1 53 132.5 136.6 140.6 1.1 60 147.2 151.8 156.3 1.1 70 162.0 167.0 172.0 1.1 80 178.7 184.2 189.7 1.1 94 210.1 216.6 open 1.1 99 27 Refer to Figures 3 and 4. The controller achieves current balancing through matching the ISEN pin voltages. Risen and Cisen form filters to remove the switching ripple of the phase node voltages. It is recommended to use rather long RisenCisen time constant such that the ISEN voltages have minimal ripple and represent the DC current flowing through the inductors. Recommended values are Rs = 10kΩ and Cs = 0.22µF. FN8315.0 May 9, 2013 ISL95839 Slew Rate Compensation Circuit for VID Transition Rdroop Vcore Rvid Cvid OPTIONAL FB Ivid Idroop_vid E/A COMP Σ VDACDAC VIDs VID RTN X1 INTERNAL TO IC VSSSENSE VSS During a large VID transition, the DAC steps through the VIDs at a controlled slew rate. For example, the DAC may change a tick (5mV) per 0.5µs, controlling output voltage Vcore slew rate at 10mV/µs. Figure 28 shows the waveforms of VID transition. During VID transition, the output capacitor is being charged and discharged, causing Cout x dVcore/dt current on the inductor. The controller senses the inductor current increase during the up transition, as the Idroop_vid waveform shows, and will droop the output voltage Vcore accordingly, making Vcore slew rate slow. Similar behavior occurs during the down transition. To get the correct Vcore slew rate during VID transition, one can add the Rvid-Cvid branch, whose current Ivid cancels Idroop_vid. It’s recommended to choose the R, C values from the reference design as a starting point. then tweak the actual values on the board to get the best performance. During normal transient response, the FB pin voltage is held constant, therefore is virtual ground in small signal sense. The Rvid - Cvid network is between the virtual ground and the real ground, and hence has no effect on transient response. VID Vfb Ivid Vcore Idroop_vid FIGURE 28. SLEW RATE COMPENSATION CIRCUIT FOR VID TRANSITION 28 FN8315.0 May 9, 2013 IN R18 10UF 10UF 22UF 22UF C127 22UF 22UF C129 22UF C125 C124 22UF 22UF 22UF C123 C122 C117 470UF 22UF C118 C120 22UF --------------------------------- C119 C121 C113 22UF 470UF C114 22UF 10 VSUMNG R131 3.65K VSUMPG R127 PLACE NEAR L1 10 FN8315.0 May 9, 2013 FIGURE 29. ISL95839 1+1 REFERENCE DESIGN 10UF C33 10UF --------------------------------- 22UF 22UF C67 22UF C63 22UF 22UF C59 22UF C302 470UF 470UF 470UF C301 C53 22UF 22UF C54 22UF 10UF 22UF C315 C52 C39 470UF C40 22UF C41 22UF VSUMN C47 R88 3.65K 10 C68 C64 C60 C48 10UF 10UF C319 10UF C318 10UF C317 C316 10UF 10UF C314 C313 3300PF 649 IN VSUMN 10UF R109 C312 383 C81 10UF R38 R30 C311 C13 CPUVSSSENSE 0.01UF ---- DNP ---- 10UF IN OPTIONAL C310 CPUVCCSENSE 10 C20 R17 IN 1UF 1UF C22 C16 BOOT1 PGOOD IN 0.1UF 11K ----------> R42 R41 CPUVCORE VSUMP C130 680PF C19 2K 0.22UF R155 IN OUT VSUMP R63 R11 1000PF 133K PGOOD C18 R7 1.91K +3.3V OUT C3 2200PF 2.1K CPUVCORE OUT Q3 OUT 71.5K C11 118 Q2 0.36UH 0.22UF C30 0 R19 R10 56PF +5V L1 R56 +5V DNP C6 R4 IN 10K 2.61K NTC IN COMP EP FB 470K NTC ISUMN UGATE1 RTN 3.83K PHASE1 NTC ISUMP R46 FB2 ISEN1 27.4K R49 1 PWM3 LGATE1 VR_HOT# R80 IN R37 VDD ISL95839HRTZ SDA OUT +5V VCCP ------------------------------------------------------------------COMPONENT PART NUMBER (MANUFACTURER) ------------------------------------------------------------------EEFLX0D471R4(PANASONIC) - C39,C52,C301,C302,C113,C117 2TPW470M4R(SANYO) T520V277M2R5A(1_E4R5-6666(KEMET) ------------------------------------------------------------------GRM21BR61C226KE15L(TDK) - C40,C41,C47,C48,C53,C54 C59-C68,C114,C115,C118-C127 (KYOCERA,MURATA,TAIYO,SAMSUNG) ------------------------------------------------------------------- C310-C319 GRM21BR61C106KE15L(TDK) (KYOCERA,MURATA,TAIYO,SAMSUNG) ------------------------------------------------------------------25SP56M(SANYO) - C24,C25 ------------------------------------------------------------------- L1,L4 MPCH1040LR36(NEC-TOKIN) ETQP4LR36AFC(PANASONIC) ------------------------------------------------------------------BSC052N03LS-T(INFINEON) - Q2,Q16 ------------------------------------------------------------------BSC011N03LS-T(INFINEON) - Q3,Q17 ------------------------------------------------------------------ERT-J1VR103J-T(PANASONIC) - R42,R43 ------------------------------------------------------------------- R20,R45 NCP18WM474J03RB-T(MURATA) ------------------------------------------------------------------- C27 C24 LGATE2 U1 --------------------------------- BOOT1G PHASE1G UGATE1G VR_ON LGATE1G FBG PHASE2 ALERT# R4 = 71.5K VBOOT = 1.1V ICCMAX = 24A COMPG VR_ON ---- R8 130 54.9 ---R5 499 75 ---R12 130 R214 R213 BOOT2 UGATE2 SCLK 43 VIN IN IMON NTCG -------CONTROLLER SIDE PULL-UP R202 VR_HOT# 0.22UF IMONG ISEN2 IN C30 0 ISUMPG IMON ISEN3 SDA R1 97.6K ----- IN -------- ----C12 ALERT# -------CPU SIDE PULL-UP 97.6K 0.01UF 330PF IN C14 R56 ISL95839 -------- C87 1UF SCLK 3.83K IN ---- VTT NTC R26 PGOODG R20 470K 0.01UF C8 R54 27.4K RTNG R112 ISUMNG IMONG 10K NTC +3.3V IN C25 1.91K C115 PGGODG OUT R183 OUT 3300PF 649 10 VSUMNG IN PLACE NEAR L4 56UF R32 C112 R39 383 C93 GTVCORE OUT Q17 56UF R9 1000PF 133K 2.61K R36 11K C94 R31 L4 0.36UH ----> C51 R25 2.1K R43 56PF C97 2200PF Q16 OUT 29 R23 C86 C88 VSUMPG IN 0.1UF IN 118 0.01UF GTVSSSENSE C90 ---- 28.7K DNP R24 R2 C95 IN 2K 0.22UF GTVCCSENSE 680P ----- ----C89 ---- 10 R55 C99 OPTIONAL R16 IN 330PF GTVCORE C110 R2 = 28.7K FSW = 400KHZ ICCMAX_GT = 24A ISL95839 Layout Guidelines ISL95839 PIN # SYMBOL LAYOUT GUIDELINES BOTTOM PAD GND Connect this ground pad to the ground plane through low impedance path. Recommend use of at least 5 vias to connect to ground planes in PCB internal layers. 2 IMONG 3 IMON Connect a resistor in parallel with a capacitor from IMON and IMONG pins to ground respectively. Place the resistors and capacitors as close as possible to the controller. 4 NTCG 5, 6, 7 8 The NTC thermistor needs to be placed close to the thermal source that is monitored to determine AXG Vcore thermal throttling. Recommend placing it at the hottest spot of the AXG Vcore VR. SCLK, Follow Intel recommendation. ALERT#, SDA VR_HOT# No special consideration. 9 FB2 Place the compensator components in general proximity of the controller. 10 NTC The NTC thermistor needs to be placed close to the thermal source that is monitored to determine CPU Vcore thermal throttling. Recommend placing it at the hottest spot of the CPU Vcore VR. 11 ISEN3 12 ISEN2 13 ISEN1 Each ISEN pin has a capacitor (Cisen) decoupling it to VSUMN, then through another capacitor (Cvsumn) to GND. Place Cisen capacitors as close as possible to the controller and keep the following loops small: 1. Any ISEN pin to another ISEN pin 2. Any ISEN pin to GND The red traces in the following drawing show the loops that need to minimized. Phase1 L3 Ro Risen ISEN3 Cisen Phase2 Vo L2 Ro Risen ISEN2 Cisen Phase3 Risen ISEN1 GND 14 ISUMP 15 ISUMN L1 Ro Vsumn Cisen Cvsumn Place the current sensing circuit in general proximity of the controller. Place capacitor Cn very close to the controller. Place the NTC thermistor next to VR1 phase-1 inductor (L1) so it senses the inductor temperature correctly. Each phase of the power stage sends a pair of VSUMP and VSUMN signals to the controller. Run these two signals traces in parallel fashion with decent width (>20mil). IMPORTANT: Sense the inductor current by routing the sensing circuit to the inductor pads. Route R63 and R71 to VR1 phase-1 side pad of inductor L1. Route R88 to the output side pad of inductor L1. Route R65 and R72 to VR1 phase-2 side pad of inductor L2. Route R90 to the output side pad of inductor L2. If possible, route the traces on a different layer from the inductor pad layer and use vias to connect the traces to the center of the pads. If no via is allowed on the pad, consider routing the traces into the pads from the inside of the inductor. The following drawings show the two preferred ways of routing current sensing traces. INDUCTOR INDUCTOR VIAS CURRENT-SENSING TRACES 30 CURRENT-SENSING TRACES FN8315.0 May 9, 2013 ISL95839 Layout Guidelines (Continued) ISL95839 PIN # SYMBOL 16 RTN Place the RTN filter in close proximity of the controller for good decoupling. 17 FB Place the compensator components in general proximity of the controller. LAYOUT GUIDELINES 18 COMP 19 PGOOD No special consideration. 20 BOOT1 Use decent wide trace (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. 21 UGATE1 22 PHASE1 Run these two traces in parallel fashion with decent width (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. Recommend routing PHASE1 trace to VR1 phase-1 high-side MOSFET (Q2 and Q8) source pins instead of general copper. 23 LGATE1 Place the RTNG filter in close proximity of the controller for good decoupling. 24 PWM3 No special consideration. 25 VDD A capacitor decouples it to GND. Place it in close proximity of the controller. 26 VCCP A capacitor decouples it to GND. Place it in close proximity of the controller. 27 LGATE2 Use decent width (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. 28 PHASE2 29 UGATE2 Run these two traces in parallel fashion with decent width (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. Recommend routing PHASE2 trace to VR1 phase-2 high-side MOSFET (Q4 and Q10) source pins instead of general copper. 30 BOOT2 Use decent wide trace (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. 31 BOOT1G Use decent wide trace (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. 32 UGATE1G 33 PHASE1G Run these two traces in parallel fashion with decent width (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. Recommend routing PHASE1G trace to VR2 phase-1 high-side MOSFET source pins instead of general copper 34 LGATE1G Use decent width (>30mil). Avoid any sensitive analog signal trace from crossing over or getting close. 35 VR_ON No special consideration. 36 PGOODG No special consideration. 37 COMPG Place the compensator components in general proximity of the controller. 38 FBG 39 RTNG 40 ISUMNG 1 ISUMPG Place the RTNG filter in close proximity of the controller for good decoupling. Place the current sensing circuit in general proximity of the controller. Place capacitor Cn very close to the controller. Place the NTC thermistor next to VR2 phase-1 inductor (L1) so it senses the inductor temperature correctly. See ISUMN and ISUMP pins for layout guidelines of current-sensing trace routing. 31 FN8315.0 May 9, 2013 ISL95839 Typical Performance FIGURE 30. VR1 SOFT-START, VIN = 19V, IO = 5A, VID = 1.1V, CH1: VR_ON, CH2: VR1 VO, CH3: PGOOD FIGURE 31. VR2 SOFT-START, VIN = 19V, IO = 5A, VID = 1.1V, CH1: VR_ON, CH2: VR2 VO, CH3: PGOODG FIGURE 32. 1 VR1 AND VR2 SOFT-START, VIN = 7V, Io_VR1 = 30A, Io_VR2 = 30A, VID = 1.1V, CH1: VR1 VO, CH2: VR2 VO, CH3: PGOOD, CH4: PHASE1G FIGURE 33. 1 VR1 AND VR2 SOFT-START, VIN = 20V, IO_VR1 = 30A, IO_VR2 = 30A, VID = 1.1V, CH1: VR1 VO, CH2: VR2 VO, CH3: PGOOD, CH4: PHASE1G FIGURE 34. VR1 SHUT DOWN, VIN = 12V, IO = 5A, VID = 1.1V, CH1: PGOOD, CH2: VR1 VO, CH3: VR_ON, CH4: COMP FIGURE 35. VR2 SHUT DOWN, VIN = 12V, IO = 5A, VID = 1.1V, CH1: PGOODG, CH2: VR2 VO, CH3: VR_ON, CH4: COMPG 32 FN8315.0 May 9, 2013 ISL95839 Typical Performance (Continued) FIGURE 36. VR1 PRE-CHARGED START UP, VIN = 19V, VID = 1.1V, V_PRE-CHARGE VOLTAGE = 0.5V, CH1: PHASE1, CH2: VR1 VO, CH3: VR_ON, CH4: PGOOD FIGURE 37. VR2 PRE-CHARGED START UP, VIN = 19V, VID = 1.1V, V_PRE-CHARGE VOLTAGE = 1.3V, CH1: PHASE1G, CH2: VR2 VO, CH3: VR_ON, CH4: PGOODG FIGURE 38. VR1 STEADY STATE, VIN = 19V, IO = 94A, VID = 0.9V CH1: PHASE1, CH2: VR1 VO, CH3: PHASE2, CH4: PHASE3 FIGURE 39. VR1 LOAD RELEASE RESPONSE, VIN = 12V, VID = 0.9V, IO = 28A/94A, SLEW TIME= 150ns, LL = 1.9mΩ, CH1: PHASE1, CH2: VR1 VO, CH3: PHASE2, CH4: PHASE3 FIGURE 40. VR1 LOAD INSERTION RESPONSE, VIN = 12V, VID = 0.9V, IO = 28A/94A, SLEW TIME= 150ns, LL = 1.9mΩ, CH1: PHASE1, CH2: VR1 VO, CH3: PHASE2, CH4: PHASE 33 FN8315.0 May 9, 2013 ISL95839 Typical Performance (Continued) FIGURE 41. VR1 PS2 LOAD TRANSIENT RESPONSE, VIN = 19V, VID = 0.6V, IO = 1A/5A, SLEW TIME= 150ns, LL = 1.9mΩ, CH1: PHASE1, CH2: VR1 VO FIGURE 42. VR2 PS2 LOAD TRANSIENT RESPONSE, VIN = 19V, VID = 0.6V, IO = 1A/5A, SLEW TIME= 150ns, LL = 3.9mΩ, CH1: PHASE1G, CH2: VR2 VO FIGURE 43. VR1 SETVID-FAST RESPONSE, IO = 5A, VID = 0.3V - 0.9V, CH1: PHASE1, CH2: VR1 VO, CH3: SDA, CH4: ALERT# FIGURE 44. VR2 SETVID-FAST RESPONSE, IO = 5A, VID = 0.5V - 0.8V, CH1: PHASE1G, CH2: VR2 VO, CH3: SDA, CH4: ALERT# FIGURE 45. VR1 SETVID-SLOW RESPONSE, IO = 5A, VID = 0.3V - 0.9V, CH1: PHASE1, CH2: VR1 VO, CH3: SDA, CH4: ALERT# FIGURE 46. VR2 SETVID-SLOW RESPONSE, IO = 5A, VID = 0.4V - 0.9V, CH1: PHASE1G, CH2: VR2 VO, CH3: SDA, CH4: ALERT# 34 FN8315.0 May 9, 2013 ISL95839 Typical Performance (Continued) FIGURE 47. VR1 SETVID DECAY PRE_EMPTIVE BEHAVIOR, SETVID-FAST 0.8V AFTER SETVID DECAY 0V FROM 0.9V, IO = 4A, CH1: PHASE1, CH2: VR1 VO, CH3: SDA, CH4: PHASE2 Revision History The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you have the latest Rev. DATE REVISION May 9, 2013 FN8315.0 CHANGE Initial Release. About Intersil Intersil Corporation is a leader in the design and manufacture of high-performance analog, mixed-signal and power management semiconductors. The company's products address some of the largest markets within the industrial and infrastructure, personal computing and high-end consumer markets. For more information about Intersil, visit our website at www.intersil.com. For the most updated datasheet, application notes, related documentation and related parts, please see the respective product information page found at www.intersil.com. You may report errors or suggestions for improving this datasheet by visiting www.intersil.com/en/support/ask-an-expert.html. Reliability reports are also available from our website at http://www.intersil.com/en/support/qualandreliability.html#reliability For additional products, see www.intersil.com/en/products.html Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems as noted in the quality certifications found at www.intersil.com/en/support/qualandreliability.html Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. 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For information regarding Intersil Corporation and its products, see www.intersil.com 35 FN8315.0 May 9, 2013 ISL95839 Package Outline Drawing L40.5x5 40 LEAD THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 1, 9/10 4X 3.60 5.00 A B 36X 0.40 6 PIN #1 INDEX AREA 3.50 5.00 6 PIN 1 INDEX AREA 0.15 (4X) 40X 0.4± 0 .1 BOTTOM VIEW TOP VIEW 0.20 b 4 0.10 M C A B PACKAGE OUTLINE 0.40 0.750 SEE DETAIL “X” SIDE VIEW 3.50 5.00 0.050 // 0.10 C C BASE PLANE SEATING PLANE 0.08 C (36X 0.40 0.2 REF (40X 0.20) C (40X 0.60) 5 0.00 MIN 0.05 MAX TYPICAL RECOMMENDED LAND PATTERN DETAIL "X" NOTES: 1. Dimensions are in millimeters. Dimensions in ( ) for Reference Only. 2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994. 3. Unless otherwise specified, tolerance : Decimal ± 0.05 4. Dimension b applies to the metallized terminal and is measured between 0.15mm and 0.27mm from the terminal tip. 5. Tiebar shown (if present) is a non-functional feature. 6. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 indentifier may be 7. JEDEC reference drawing: MO-220WHHE-1 either a mold or mark feature. 36 FN8315.0 May 9, 2013