MAX8664 19-0796 Rev 0 4/07 Low-Cost, Dual-Output, Step-Down Controller with Fast Transient Response General Description Features The MAX8664 dual-output PWM controller is a low-cost, 0.8% Output Accuracy Over Load and Line high-performance solution for systems requiring dual Operates from a Single 4.5V to 28V Supply power supplies. It provides two individual outputs that Simple Compensation for Any Type of Output operate 180 out-of-phase to minimize input current Capacitor ripple, and therefore, capacitance requirements. Built-in drivers are capable of driving external MOSFETs to Internal 6.5V Regulator for Gate Drive deliver up to 25A output current from each channel. Integrated Boost Diodes The MAX8664 operates from a 4.5V to 28V input volt- Adjustable Output from 0.6V to 0.9 x V IN age source and generates output voltages from 0.6V up to 90% of the input voltage on each channel. Total Digital Soft-Start Reduces Inrush Current output regulation error is less than 0.8% over load, 100kHz to 1MHz Adjustable Switching line, and temperature. 180 Out-of-Phase Operation Reduces Input The MAX8664 operates with a constant switching fre- Ripple Current quency adjustable from 100kHz to 1MHz. Built-in boost Overcurrent and Overvoltage Protection diodes reduce external component count. Digital soft- start eliminates input inrush current during startup. The External Reference Input for Second Controller second output has an optional external REFIN2, facili- Prebiased Startup Operation tating tracking supply applications. Each output is capable of sourcing and sinking current, making the Ordering Information device a great solution for DDR applications. PIN- PKG FAULT The MAX8664 employs Maxims proprietary peak volt- PART PACKAGE CODE ACTION age-mode control architecture that provides superior MAX8664A EEP+ 20 QSOP E20-1 Independent transient response during either load or line transients. This architecture is easily stabilized using two resistors MAX8664B EEP+ 20 QSOP E20-1 Joint and one capacitor for any type of output capacitors. Fast Note: This device operates over the -40C to +85C operating transient response requires less output capacitance, temperature range. consequently reducing total system cost. The MAX8664B +Denotes lead-free package. latches off both controllers during a fault condition, while the MAX8664A allows one controller to continue to func- Typical Operating Circuit tion when there is a fault in the other controller. IN2 VL IN Applications ILIM2 ILIM1 IN1 Desktop and Notebook PCs OUT2 OUT1 Graphic Cards DH2 DH1 BST2 BST1 ASIC/CPU/DSP Power Supplies Set-Top Box Power Supply LX1 LX2 Printer Power Supply DL2 DL1 Network Power Supply POL Power Supply MAX8664 GND PGND FB1 FB2 REFIN2 PWRGD OSC/EN12 V CC Pin Configuration appears at end of data sheet. Maxim Integrated Products 1 For pricing delivery, and ordering information please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLELow-Cost, Dual-Output, Step-Down Controller with Fast Transient Response ABSOLUTE MAXIMUM RATINGS IN to GND ...........................................................-0.3V to +30V ILIM to GND ...............................................-0.3V to (V + 0.3V) IN VL to GND...................................................................-0.3 to +8V ILIM to LX ............................................................-0.6V to +30V IN, BST to VL ........................................................-0.3V to +30V OSC/EN12, REFIN2 to GND .....................-0.3V to (V + 0.3V) VCC V , FB , PWRGD to GND.......................................-0.3V to +6V VL Continuous Current ..............................................125mA CC RMS VL to V ....................................................................-2V to +8V V Continuous Current..............................................10mA CC CC RMS PGND to GND .......................................................-0.3V to +0.6V Continuous Power Dissipation (T = +70C) (Note 1) A DL to PGND...............................................-0.3V to (V + 0.3V) 20-Pin QSOP (derate 11.0mW/C above +70C).........884mW VL DH to PGND............................................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C BST BST to GND.............................................................-0.3V to 38V Junction Temperature......................................................+150C BST to LX................................................................-0.3V to +8V Storage Temperature Range .............................-65C to +150C LX to PGND .................-1V (-2.5V for < 50ns transient) to +30V Lead Temperature (soldering, 10s) .................................+300C DH to LX ................................................-0.3V to (V + 0.3V) BST Note 1: Package mounted on a multilayer PCB. 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 (V = 12V, R to GND = 56.1k , REFIN2 = V , T = -40C to +85C, unless otherwise noted. Typical values are at IN OSC/EN12 CC A T = +25C.) (Note 2) A PARAMETER CONDITIONS MIN TYP MAX UNITS SUPPLY VOLTAGES 7.2 28.0 IN Supply Voltage V IN = VL = V 4.5 5.5 CC VL Output Voltage 7.2V < V < 28V, 0 < I < 60mA 6.10 6.6 6.75 V IN VL V Output Voltage 7.2V < V < 28V, 0 < I < 5mA 4.5 5.0 5.5 V CC IN CC Rising 3.4 3.5 3.6 V V Undervoltage Lockout CC (UVLO) Hysteresis 350 mV V = 12V, I 0.095 0.2 OSC/EN12 not IN IN Standby Supply Current mA connected V = V = V = 5V, I + I + I 0.08 0.2 CC IN VL IN VL VCC V = 12V, I 1.4 2.5 No switching, IN IN Operating Supply Current mA V = 0.65V FB V = V = V = 5V, I + I + I 1.1 1.8 CC IN VL IN VL VCC REGULATOR SPECIFICATIONS T = 0C to +85C 0.5955 0.600 0.6045 A Reference Accuracy V T = -40C to +85C 0.5930 0.600 0.6070 A T = 0C to +85C 0.5952 0.600 0.6048 A V = V REFIN2 VCC T = -40C to +85C 0.5925 0.600 0.6075 FB Regulation Accuracy A V V = 1.000V 0.995 1.000 1.005 REFIN2 REFIN2 to Internal Reference V - V - VCC VCC Not to be switched during operation 2 V Switchover Threshold 0.7 0.3 REFI N2 M ax im um P r ogr am V olta ge 1.3 V REFIN2 Disable Threshold 50 mV FB Input Bias Current V = 0.5V 3 nA FB REFIN2 Bias Current V = 0.65V 3 nA REFIN2 FB Propagation Delay FB rising to DH falling 90 ns 2 MAX8664