MAX1762/MAX1791 19-1923 Rev 1 10/05 High-Efficiency, 10-Pin MAX, Step-Down Controllers for Notebooks General Description Features The MAX1762/MAX1791 PWM step-down controllers High Operating Frequency (300kHz) provide high efficiency, excellent transient response, No Current-Sense Resistor and high DC output accuracy needed for stepping down high-voltage batteries to generate low-voltage Accurate Current Limit CPU core, I/O, and chipset RAM supplies in notebook 1% Total DC Error over Line and During computers and PDAs. Continuous Conduction Maxims proprietary Quick-PWM pulse-width modula- tor is a free-running constant on-time type with input Dual Mode Fixed Output feed-forward. Its high operating frequency (300kHz) 1.8V/2.5V/adj (MAX1762) allows small external components to be utilized in PC 3.3V/5.0V/adj (MAX1791) board area-critical applications such as subnotebook 0.5V to 5.5V Output Adjust Range computers and smart phones. PWM operation occurs at heavy loads, and automatic switchover to pulse-skip- 5V to 20V Input Range ping operation occurs at lighter loads. The external Automatic Light-Load Pulse Skipping Operation high-side p-channel and low-side n-channel MOSFETs require no bootstrap components. The MAX1762/ Free-Running On-Demand PWM MAX1791 are simple, easy to compensate, and do not Foldback Mode UVLO have the noise sensitivity of conventional fixed-frequen- cy current-mode PWMs. PFET/NFET Synchronous Buck These devices achieve high efficiency at a reduced 4.65V at 25mA Linear Regulator Output cost by eliminating the current-sense resistor found in traditional current-mode PWMs. Efficiency is further 5A Shutdown Supply Current enhanced by their ability to drive synchronous-rectifier 230A Quiescent Supply Current MOSFETs. The MAX1762/MAX1791 come in a 10-pin MAX package and offer two fixed voltages (Dual 10-Pin MAX Package Mode) for each device, 1.8V/2.5V/adj (MAX1762) and 3.3V/5.0V/adj (MAX1791). Ordering Information Applications PART TEMP RANGE PIN-PACKAGE Notebooks Handy-Terminals MAX1762EUB -40C to +85C 10 MAX Subnotebooks PDAs MAX1791EUB -40C to +85C 10 MAX Digital Cameras Smart Phones 1.8V/2.5V Logic Pin Configuration and I/O Supplies TOP VIEW Typical Operating Circuit V BATT (5V TO 20V) VL 1 10 VP REF 2 9 DH VL VP MAX1762 FB 3 8 CS MAX1791 MAX1762 OUT 4 7 DL MAX1791 SHDN 5 6 GND REF DH V OUT 1.8V/3.3V CS FB MAX OUT DL Quick-PWM, Dual Mode, and Foldback Mode are a trade- SHDN GND marks of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEHigh-Efficiency, 10-Pin MAX, Step-Down Controllers for Notebooks ABSOLUTE MAXIMUM RATINGS Continuous Power Dissipation (T = +70C) VP, SHDN to GND ..................................................-0.3V to +22V A 10-Pin MAX (derate 5.6mW/C above +70C) ...........444mW VP to VL..................................................................-0.3V to +22V OUT, VL to GND.......................................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C Junction Temperature......................................................+150C DL, FB, REF to GND ....................................-0.3V to (VL + 0.3V) DH to GND....................................................-0.3V to (VP + 0.3V) Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C CS to GND....................................................-2.0V to (VP + 0.3V) REF Short Circuit to GND...........................................Continuous 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 = 15V, VL enabled, C = 1F, C = 0.1F, T = 0 to +85C, unless otherwise noted. Typical values are at T = +25C.) VP VL REF A A (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VP Input Voltage Range V 520V VP VL Input Voltage Range V VL (overdriven) 4.75 5.25 V VL OUT Output Voltage V = 5V to 20V, V = 4.75V to 5.25V, VP VL V 1.773 1.8 1.827 V OUT (MAX1762, 1.8V Fixed) FB = GND, continuous conduction mode OUT Output Voltage V = 5V to 20V, V = 4.75V to 5.25V, VP VL V 2.463 2.5 2.538 V OUT (MAX1762, 2.5V Fixed) FB = VL, continuous conduction mode OUT Output Voltage V = 5V to 20V, V = 4.75V to 5.25V, VP VL V 3.250 3.3 3.350 V OUT (MAX1791, 3.3V Fixed) FB = GND, continuous conduction mode OUT Output Voltage V = 7V to 20V, V = 4.75V to 5.25V, VP VL V 4.925 5 5.075 V OUT (MAX1791, 5V Fixed) FB = VL, continuous conduction mode V = 5V to 20V, V = 4.75V to 5.25V, VP VL OUT Output Voltage (Adj Mode) 1.231 1.250 1.269 V FB = OUT, continuous conduction mode Output Voltage Adjust Range 0.5 5.5 V OUT Input Resistance Adjustable-output mode 300 800 1700 k FB Input Bias Current V = 1.3V -0.1 0.1 A FB Soft-Start Ramp Time Zero to full I 1700 s LIM V = 1.25V, V = 6V 666 740 814 OUT VP On-Time (Note 2) t ns ON V = 5V, V = 6V 2550 2830 3110 OUT VP Minimum Off-Time t (Note 2) 300 400 500 ns OFF FB = GND, V = 5V, OUT forced above the VL VL Quiescent Supply Current 153 260 A regulation point FB = GND, OUT forced V = float 227 410 VL VP Quiescent Supply Current above the regulation point, A V = 5V 93 200 VL V = 20V VP VL Shutdown Supply Current V = 5V, SHDN = GND 2 15 A VL VP Shutdown Supply Current S HD N = GN D , m easured at VP , V = 0 or 5V 412 A V L VL Output Voltage I = 0 to 25mA, V = 5V to 20V 4.5 4.65 4.75 V LOAD VP 2 MAX1762/MAX1791