MAX17067 19-3106 Rev 0 1/08 Low-Noise Step-Up DC-DC Converter General Description Features The MAX17067 boost converter incorporates high- 90% Efficiency performance (at 1.2MHz), current-mode, fixed-frequency, Adjustable Output from V to 18V IN pulse-width modulation (PWM) circuitry with a built-in 0.15 n-channel MOSFET to provide a highly efficient 2.4A, 0.15, 22V Power MOSFET regulator with fast response. +2.6V to +4.0V Input Range High switching frequency (640kHz or 1.2MHz selectable) Pin-Selectable 640kHz or 1.2MHz Switching allows for easy filtering and faster loop performance. An external compensation pin provides the user flexibility in Frequency determining loop dynamics, allowing the use of small, Programmable Soft-Start low equivalent-series-resistance (ESR) ceramic output capacitors. The device can produce an output voltage Small 8-Pin MAX Package as high as 18V. Integrated Input Voltage Clamp Circuit Soft-start is programmed with an external capacitor, which sets the input-current ramp rate. The MAX17067 is avail- able in a space-saving 8-pin MAX package. The ultra- small package and high switching frequency allow the total solution to be less than 1.1mm high. Application Ordering Information LCD Displays PIN- PKG PART TEMP RANGE PACKAGE CODE MAX17067EUA+ -40C to +85C 8 MAX U8+1 + Denotes a lead-free package. Typical Operating Circuit V IN Pin Configuration 2.6V TO 4V TOP VIEW IN V OUT ON/OFF SHDN LX 1 8 COMP SS FB FREQ 2 7 MAX17067 MAX17067 FREQ GND SHDN 3 6 IN GND 4 5 LX SS FB MAX COMP MAX is a registered trademark of Maxim Integrated Products, Inc. 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-Noise Step-Up DC-DC Converter ABSOLUTE MAXIMUM RATINGS LX to GND ..............................................................-0.3V to +22V Continuous Power Dissipation (T = +70C) A SHDN, FREQ to GND ............................................-0.3V to +7.5V 8-Pin MAX (derate 4.1mW/C above +70C) ............330mW IN to GND (Note 1)...................................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C SS, COMP, FB to GND ................................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C IN RMS LX Pin Current ..............................................................1.2A Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C 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 = SHDN = 3V, FREQ = 3V, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) (Note 2) IN A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Supply Range V V < 18V 2.6 4.0 V IN OUT Output Voltage 18 V Use external limiting resistor R = 100 , IN Input Supply Clamp Voltage 6.05 6.40 6.60 V V = 10V (Note 3) IN V rising, typical hysteresis is 50mV, LX IN V Undervoltage Lockout UVLO 2.30 2.45 2.57 V IN remains off below this level V = 1.3V, not switching 0.3 0.6 FB Quiescent Current I mA IN V = 1.0V, switching 1.5 2.5 FB SHDN = GND, T = +25C 30 60 A Shutdown Supply Current I A IN SHDN = GND, T = +85C 30 A ERROR AMPLIFIER Feedback Voltage V Level to produce V = 1.24V 1.23 1.24 1.25 V FB COMP FB Input Bias Current I V = 1.24V 50 125 200 nA FB FB Feedback-Voltage Line Level to produce V = 1.24V, COMP 0.05 0.15 %/V Regulation 2.6V < V < 5.5V IN Transconductance g I = 5A 100 240 440 S m Voltage Gain A 3800 V/V V OSCILLATOR FREQ = GND 500 640 780 Frequency f kHz OSC FREQ = IN 1000 1200 1400 Maximum Duty Cycle DC FREQ = GND, FREQ = IN 89 92 95 % n-CHANNEL SWITCH Current Limit I V = 1V, duty cycle = 68% (Note 4) 1.8 2.4 3.4 A LIM FB On-Resistance R 150 275 m ON Leakage Current I V = 20V 10 20 A LXOFF LX Current-Sense Transresistance R 0.2 0.3 0.4 V/A CS SOFT-START Reset Switch Resistance 100 Charge Current V = 1.2V 2.5 4.5 6.5 A SS 2 MAX17067