MAX1817 19-1794 Rev 0 10/00 Compact, High-Efficiency, Dual-Output Step-Up DC-DC Converter General Description Features The MAX1817 is a compact, high-efficiency, dual-out- Dual Step-Up Converter in a Tiny 10-Pin MAX put step-up converter for portable devices that pro- Package vides both the main logic supply and the LCD bias. The Main Output device operates from an input voltage of +1.5V to +5.5V, allowing the use of 2- or 3-cell alkaline batteries, Up to 125mA Load Current or 1-cell lithium-ion (Li+) batteries. Fixed 3.3V or Adjustable 2.5V to 5.5V Up to 88% Efficiency The MAX1817s main regulator supplies 125mA at Internal Switch either a preset 3.3V or an adjustable 2.5V to 5.5V out- put voltage with up to 88% efficiency. A 0.1A shut- LCD Output down state also minimizes battery drain. The Up to 28V for LCD Bias MAX1817s secondary step-up converter provides the Internal Switch LCD bias voltage and is adjustable up to +28V. Input Voltage Range +1.5V to +5.5V Other features include a fast switching frequency to reduce the size of external components and a low qui- Minimal External Components Required escent current to maximize battery life. Both outputs can 0.1A Logic-Controlled Shutdown be independently shut down for improved flexibility. Low 15A Quiescent Supply Current The MAX1817 is supplied in a compact 10-pin MAX package. The MAX1817 evaluation kit (MAX1817EVKIT) is available to speed up design. Applications Ordering Information Organizers/Translators PART TEMP. RANGE PIN-PACKAGE MAX1817EUB -40C to +85C 10 MAX PDAs MP3 Players GPS Receivers Typical Operating Circuit Pin Configuration +1.5V TOP VIEW TO +5.5V FB 1 10 OUT ON 2 9 LX LCD MAX1817 ONLCD 3 8 GND LXLCD LX FBLCD 4 7 LXLCD AGND 5 6 N.C. ONLCD LCD ON/OFF FBLCD MAX MAX1817 MAIN ON/OFF ON OUT MAIN FB AGND GND 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.Compact, High-Efficiency, Dual-Output Step-Up DC-DC Converter ABSOLUTE MAXIMUM RATINGS OUT to GND .............................................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C ON, ONLCD, FB, FBLCD, LX to GND ......-0.3V to (V + 0.3V) Junction Temperature......................................................+150C OUT LXLCD to GND .......................................................-0.3V to +30V Storage Temperature Range .............................-65C to +150C AGND to GND .......................................................-0.3V to +0.3V Lead Temperature (soldering, 10s) .................................+300C Continuous Power Dissipation (T = +70C) A 10-Pin MAX (derate 5.6mW/C above +70C) ...........444mW LXLCD, LX Maximum Current ........................................0.5A RMS 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 = V =V = +3.3V, FB = GND, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) ON ONLCD OUT A A PARAMETER CONDITIONS MIN TYP MAX UNITS GENERAL Input Voltage Range 1.5 5.5 V R = 35 1.5 LOAD Startup Voltage V R = , V = 1.35V 1.2 1.55 LOAD FB Quiescent Current from OUT V = V = 1.35V, FB FBLCD 510 A (Main Only) V = 0 ONLCD Quiescent Current from OUT V = V = 1.35V 15 30 A FB FBLCD Shutdown Quiescent Current V = V = 0 0.1 1 A ON ONLCD MAIN OUTPUT V rising, V = 1.35V 2.2 2.4 OUT FB OUT Undervoltage Lockout V V falling, V = 1.35V 1.95 2.15 OUT FB Fixed-Mode Output Voltage V 45mV 3.14 3.3 3.47 V FB Adjustable-Mode FB Regulation 1.20 1.25 1.30 V Voltage FB Input Bias Current V = 1.35V 50 nA FB TM FB Dual Mode Threshold 45 75 105 mV Output Voltage Adjustment 2.5 5.5 V Range Maximum LX On-Time V = 0.5V 2.4 5 7.5 s FB Zero Crossing Comparator 020 40 mV Threshold (V - V ) LX OUT Zero Crossing Comparator V = +0.5V 22 45 70 s FB Backup Timer I = 100mA, OUT Line Regulation 1.6 % V = +2V to +3V IN V = +2.5V, IN Load Regulation 1.6 % I = 10mA to 100mA LOAD LX On-Resistance V = 3.3V, I = 100mA 0.35 0.65 OUT LX LX Current Limit 0.5 0.75 1.05 A Dual Mode is a trademark of Maxim Integrated Products. 2 MAX1817