MAX8775 19-0670 Rev 0 11/06 Dual and Combinable Graphics Core Controller for Notebook Computers General Description Features Dual-Output, Fixed-Frequency, Current-Mode The MAX8775 is a dual, step-down, interleaved, fixed- Control frequency, switch-mode power-supply (SMPS) con- troller with synchronous rectification. It is intended for Combinable Output for Higher Currents GPU cores and I/O power generation in battery-pow- Dynamic Output Voltages with Automatic Fault ered systems. Flexible configuration allows the Blanking and Transition Control MAX8775 to operate as two independent single-phase True Out-of-Phase Operation regulators, or as one high-current two-phase regulator. True Differential Current Sense for Accurate Configured in separate mode, the MAX8775 provides Current Limit and Current Balance power to two dynamic voltage rails, one for the GPU 4V to 26V Input Range core and the other for the I/O power rail. Configured in 100kHz to 600kHz Switching Frequency combined mode, the MAX8775 functions as a two- phase, high-current, single-output GPU core regulator, 0.5V to 2.5V Adjustable Outputs powering the high-performance GPU engines used in Internal Integrator for High Output Accuracy gaming machines and media center notebooks. Stable with Low-ESR Output Capacitors The REFIN voltage setting allows for multiple dynamic Independent Selectable PWM and Skip-Mode output voltages required by the different GPU operating Operation and sleep states. Automatic fault blanking, forced-PWM Independent Power-Good Outputs operation, and transition control are achieved by detecting the voltage change at REFIN. Fixed-frequen- Soft-Start and Soft-Stop cy operation with 180 out-of-phase interleaving mini- 2.5V Precision Reference mizes input ripple current from the lowest input < 1A Typical Shutdown Current voltages up to the 26V maximum input. Current-mode control allows the use of low-ESR output capacitors. Ordering Information Internal integrators maintain high output accuracy over the full line-and-load range, in both forced-PWM mode PIN- PKG PART TEMP RANGE and pulse-skipping mode. True differential current PACKAGE CODE sensing provides accurate output current limit and cur- 32 Thin QFN rent balance when operated in combined mode. MAX8775ETJ+ -40C to +85C T3255-5 5mm x 5mm Independent on/off and skip control allows flexible +Denotes lead-free package. power sequencing and power management. Voltage- controlled soft-start reduces inrush current. Soft-stop Pin Configuration gradually ramps the output voltage down, preventing negative voltage dips. TOP VIEW Applications 24 23 22 21 20 19 18 17 2 to 4 Li+ Cells Battery-Powered Devices DH1 25 16 DH2 Media Center and Gaming Notebooks ON1 26 15 ON2 GPU and I/O Power Supplies 27 14 CSL2 CSL1 Tracking Output Power Supplies 13 CSH2 CSH1 28 MAX8775 29 12 SKIP1 SKIP2 PGOOD1 30 11 PGOOD2 DTRANS 31 10 CCI2 32 9 SLEW2 SLEW1 12 3 45 6 7 8 THIN QFN 5mm x 5mm Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE OVP1 BST1 OSC LX1 REFIN1 DL1 V V CC DD AGND PGND REF DL2 LX2 REFIN2 BST2 OVP2Dual and Combinable Graphics Core Controller for Notebook Computers ABSOLUTE MAXIMUM RATINGS V V , CSH , CSL to AGND............................-0.3V to +6V AGND to PGND.....................................................-0.3V to +0.3V DD, CC ON , SKIP , PGOOD to AGND ..............................-0.3V to +6V REF Short Circuit to AGND.........................................Continuous OVP , REFIN to AGND ...........................................-0.3V to +6V REF Current ......................................................................+10mA DTRANS to AGND....................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) A REF, OSC, SLEW , CCI2 to AGND ...........-0.3V to (V + 0.3V) 32-Pin, 5mm x 5mm, Thin QFN CC BST1, BST2 to AGND.............................................-0.3V to +36V (derate 21.3mW/C above +70C).............................1702mW LX1 to BST1..............................................................-6V to +0.3V Operating Temperature Range ...........................-40C to +85C LX2 to BST2..............................................................-6V to +0.3V Junction Temperature......................................................+150C DH1 to LX1 ..............................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C BST1 DH2 to LX2 ..............................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C BST2 DL1, DL2 to PGND .....................................-0.3V to (V + 0.3V) DD Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (Circuit of Figure 1, V = 12V, SKIP = PGND = AGND, ON = V = 5V, separate mode, T = 0C to +85C, unless otherwise IN CC A noted. Typical values are at T = +25C.) A PARAMETER SYMB O L CONDITIONS MINTYPMAXUNITS INPUT SUPPLIES V 426 IN Input Voltage Range V V V , V 4.5 5.5 BIAS CC DD V Undervoltage Lockout Threshold V Rising edge, 50mV typical hysteresis 4.1 4.25 4.5 V CC UVLO Quiescent Supply Current (V)I CSL forced above their regulation points 1.5 2.5 mA CC CC CSL forced above their regulation points, Quiescent Supply Current (V)I < 1 5 A DD DD SKIP mode Shutdown Supply Current (V)I ON1 = ON2 = GND < 1 5 A CC C C (S H D N) Shutdown Supply Current (V)I ON1 = ON2 = GND < 1 5 A DD D D (S H D N) SMPS CONTROLLERS With respect to REFIN , V - REFIN Output Voltage Accuracy REFIN = 0.5V to 2.5V, -5 0 +5 mV V CSL SKIP = V or GND (Note 1) CC Output Voltage-Adjust Range V Either SMPS (Note 2) 0.5 2.5 V CSL REFI N Op er ati ng V olta ge- Ad j ust RangeV Either SMPS (Note 2) 0.5 2.5 V REFIN REFINOK Threshold Either SMPS 0.1 V REFIN Transient Detection Threshold 5mV (typ) hysteresis 25 mV V - V - CC CC Combined-Mode Enabled Threshold V 3 V REFIN2 1 0.4 DC Load Regulation Either SMPS, SKIP = V , zero to full load -0.1 % CC Line Regulation Error Either SMPS, 4V < V < 26V 0.03 %/V IN R = 143k (f = 300kHz nominal) -10 +10 OSC OSC Switching-Frequency Accuracy f % OSC R = 71.5k (f = 600kHz nominal) to OSC OSC (Note 3) -15 +15 432k (f = 99kHz nominal) OSC Maximum Duty Factor D 91 93 % MAX Minimum On-Time t (Note 4) 150 ns ONMIN 2 MAX8775