MAX863 19-1218 Rev 2 2/98 Dual, High-Efficiency, PFM, Step-Up DC-DC Controller General Description Features The MAX863 dual-output DC-DC converter contains Smallest Dual Step-Up Converter: 16-Pin QSOP two independent step-up controllers in a single com- 90% Efficiency pact package. This monolithic Bi-CMOS design draws only 85A when both controllers are on. The input 1.5V Start-Up Voltage range extends down to 1.5V, permitting use in organiz- 85A Max Total Quiescent Supply Current ers, translators, and other low-power hand-held prod- ucts. The MAX863 provides 90% efficiency at output 1A Shutdown Mode loads from 20mA to over 1A. This space-saving device Independent Shutdown Inputs is supplied in a 16-pin QSOP package that fits in the same area as an 8-pin SOIC. Drives Surface-Mount, Dual N-Channel MOSFETs The device uses a current-limited, pulse-frequency- Low-Battery Input/Output Comparator modulated (PFM) control architecture that reduces start- up surge currents and maintains low quiescent currents Step-Up/Down Configurable for excellent low-current efficiency. Each controller drives a low-cost, external, N-channel MOSFET switch, Ordering Information whose size can be optimized for any output current or voltage. PART TEMP. RANGE PIN-PACKAGE In larger systems, two MAX863s can be used to gener- MAX863C/D 0C to +70C Dice* ate 5V, 3.3V, 12V, and 28V from just two or three bat- MAX863EEE -40C to +85C 16 QSOP tery cells. An evaluation kit (MAX863EVKIT) is available to speed designs. For a single-output controller, refer to *Dice are tested at T = +25C. A the MAX608 and MAX1771 data sheets. Applications Typical Operating Circuit 2- and 3-Cell Portable Equipment Organizers V IN Translators Hand-Held Instruments Palmtop Computers Personal Digital Assistants (PDAs) OUT2 OUT1 Dual Supply (Logic and LCD) SENSE1 V BOOT DD Pin Configuration N N EXT1 EXT2 CS1 CS2 TOP VIEW SENSE1 1 16 REF MAX863 V 2 15 SHDN2 DD LBO FB2 FB1 3 14 LBI LOW-BATTERY BOOT 4 MAX863 13 LBO DETECTOR OUTPUT SHDN1 ON/OFF LBI CS1 5 12 FB2 SHDN2 EXT1 6 11 SHDN1 REF GND 7 10 CS2 FB1 PGND GND PGND 8 9 EXT2 QSOP Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT MANUAL AVAILABLEDual, High-Efficiency, PFM, Step-Up DC-DC Controller ABSOLUTE MAXIMUM RATINGS V to GND............................................................-0.3V to +12V Continuous Power Dissipation (T = +70C) DD A PGND to GND .......................................................-0.3V to +0.3V QSOP (derate 8.30mW/C above +70C) ...................667mW SHDN1, SHDN2, SENSE1, LBO to GND................-0.3V to +12V Operating Temperature Range EXT1, EXT2 to PGND..................................-0.3V to (V + 0.3V) MAX863EEE ....................................................-40C to +85C DD FB1, FB2, CS1, CS2, SEL, Junction Temperature......................................................+150C LBI, BOOT to GND.................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +160C DD LBO Continuous Output Current.........................................15mA Lead Temperature (soldering, 10sec) .............................+300C EXT1, EXT2 Continuous Output Current .............................50mA 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 = +5V, I = 0mA, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) DD LOAD A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V = OUT1 = BOOT (Note 1) 1.5 11 DD V Input Voltage V V DD DD (Note 2) 2.7 11 FB1 = V 3.2 3.3 3.4 OUT1 Output Voltage DD V V OUT1 (Note 3) FB1 = GND 4.85 5 5.15 50 85 SHDN1 = SHDN2 = V , measured from V DD DD Quiescent Current I A DD SHDN1 = V , SHDN2 = GND, DD 35 60 measured from V DD Shutdown Current I SHDN1 = SHDN2 = GND 1 A DD, SHDN V = 3.3V, V = 5V, IN OUT1 Load Regulation 40 mV/A I = 0mA to 500mA, Figure 2 LOAD V = 2.7V to 5V, V = 5V, IN OUT1 Line Regulation 8 mV/V I = 300mA, Figure 2 LOAD FB1, FB2, LBI V , V 1.225 1.25 1.275 V FB LBI Threshold Voltage (Note 4) FB1, FB2, LBI Input Current I , I 210 nA FB LBI 2.7V < V < 11V 1.6 DD SHDN1, SHDN2, SEL, BOOT V V IH Input High Voltage V = 1.5V 0.7 x V DD DD 2.7V < V < 11V 0.4 SHDN1, SHDN2, SEL, BOOT DD V V IL Input Low Voltage V = 1.5V 0.2 x V DD DD SHDN1, SHDN2, SEL, BOOT I Logic input = V or GND 1 A I DD Input Current CS1, CS2 Threshold Voltage V 85 100 115 mV CS CS1, CS2 Input Current 125 A Maximum Switch On-Time t 14 17.5 22 s ON Minimum Switch Off-Time t 1.6 2 2.4 s OFF EXT Rise/Fall Time (Note 5) C = 1nF, 10% to 90% 50 ns LOAD EXT On-Resistance 5 LBO Leakage Current I V = 11V, V > 1.275V 1 A LBO LBO LBI LBO Low Level V I , = 1mA, V < 1.225V 0.1 0.4 V LBO,L LBO SINK LBI 2 MAX863