MAX8791/MAX8791B 19-0628 Rev 2 1/10 Single-Phase, Synchronous MOSFET Drivers General Description Features The MAX8791/MAX8791B are single-phase, synchro- Single-Phase, Synchronous MOSFET Drivers nous, noninverting MOSFET drivers. The MAX8791/ 0.5 Low-Side On-Resistance MAX8791B are intended to work with controller ICs like the MAX8736 or MAX8786, in multiphase notebook 0.7 High-Side On-Resistance CPU core regulators. 8ns Propagation Delay The regulators can either step down directly from the 15ns Minimum Guaranteed Dead Time battery voltage to create the core voltage, or step down from the main system supply. The single-stage conver- Integrated Boost Diode sion method allows the highest possible efficiency, while 2V to 24V Input Voltage Range the 2-stage conversion at higher switching frequency Selectable Pulse-Skipping Mode provides the minimum possible physical size. Low-Profile TQFN Package The low-side drivers are optimized to drive 3nF capaci- tive loads with 4ns/8ns typical fall/rise times, and the high-side driver with 8ns/10ns typical fall/rise times. Adaptive dead-time control prevents shoot-through cur- rents and maximizes converter efficiency. The MAX8791/MAX8791B are available in a small, lead- free, 8-pin, 3mm x 3mm TQFN package. Ordering Information Applications Notebooks/Desktops/Servers PART TEMP RANGE PIN-PACKAGE o o CPU Core Power Supplies MAX8791GTA+ -40 C to +105 C 8 TQFN-EP* o o Multiphase Step-Down Converters MAX8791BGTA+ -40 C to +105 C 8 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. Typical Operating Circuit Pin Configuration INPUT (V )* IN 5V TO 24V PWM TOP VIEW DH 65 MAX8791 MAX8791B LX 7 4 DL BST SKIP V (1.45V MAX8791 PWM SKIP OUT AT 20A) DH 8 MAX8791B 3 GND LX +5V BIAS + V DD SUPPLY 12 DL GND TQFN PAD 3mm 3mm 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. BST SKIP V PWM DDSingle-Phase, Synchronous MOSFET Drivers ABSOLUTE MAXIMUM RATINGS V to GND.................. -0.3V to +6V Continuous Power Dissipation (T = +70C) DD A SKIP to GND..................-0.3V to +6V 8-Pin 3mm x 3mm TQFN PWM to GND.................-0.3V to +6V (derate 23.8mW/C above +70C).............................1904mW DL to GND..................................................-0.3V to (V + 0.3V) Operating Temperature Range .........................-40C to +105C DD BST to GND............................................................-0.3V to +36V Junction Temperature......................................................+150C DH to LX....................................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C BST BST to V .............................................................-0.3V to +30V Lead Temperature (soldering, 10s) .................................+300C DD BST to LX...................-0.3V to +6V Soldering Temperature (reflow) .......................................+260C 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 = V = 5V, T = -40C to +105C, unless otherwise noted. Typical values are at T = +25C.) (Note 1) DD SKIP A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Voltage Range V 4.20 5.50 V DD Rising edge, PWM disabled below this level 3.7 V Undervoltage DD V V UVLO(VDD) Lockout Threshold Falling edge, PWM disabled below this level 3.0 3.5 4.0 PWM = open after the shutdown hold time has expired 0.08 0.2 Quiescent Supply SKIP = GND, PWM = GND, 0.25 0.5 I mA DD Current (V ) LX = GND (after zero crossing) DD SKIP = GND or V , PWM = V , V = 5V 0.6 1.5 DD DD BST DRIVERS t Minimum on-time 50 ON(MIN) PWM Pulse Width ns t Minimum off-time 300 OFF(MIN) DL Propagation Delay t PWM high to DL low 10 ns PWM-DL DH Propagation Delay t PWM low to DH low 14 ns PWM-DH T = 0C to +85C 15 30 A DL-to-DH Dead Time t DL falling to DH rising ns DL-DH T = -40C to +105C 15 A T = 0C to +85C 15 30 A DH-to-DL Dead Time t DH falling to DL rising ns DH-DL T = -40C to +105C 15 A t Falling, 3.0nF load 12 F DL DL Transition Time ns t Rising, 3.0nF load 14 R DL t Falling, 3.0nF load 8 F DH DH Transition Time ns t Rising, 3.0nF load 10 R DH DH, high state (pullup) 0.9 2.5 DH Driver On-Resistance R BST-LX forced to 5V ON(DH) DH, low state (pulldown) 0.7 2.3 DL, high state (pullup) 0.7 1.8 DL Driver On-Resistance R ON(DL) DL, low state (pulldown) 0.5 1.2 D H D r i ver S ource C ur r ent I DH forced to 2.5V, BST - LX forced to 5V 2.2 A DH SOURCE DH Driver Sink Current I DH forced to 2.5V, BST - LX forced to 5V 2.7 A DH SINK DL Driver Source Current I DL forced to 2.5V 2.7 A DL SOURCE DL Driver Sink Current I DL forced to 2.5V 8 A DL SINK Zero-Crossing Threshold V GND - LX, SKIP = GND 3 mV ZX Boost On-Resistance R V = 5V, D H = LX = G N D ( p ull d own state), I = 10m A512 ON(BST) D D BS T 2 MAX8791/MAX8791B