EVALUATION KIT AVAILABLE MAX1771 12V or Adjustable, High-Efficiency, Low I , Step-Up DC-DC Controller Q General Description Features The MAX1771 step-up switching controller provides 90% Efficiency for 30mA to 2A Load Currents 90% efficiency over a 30mA to 2A load. A unique cur- Up to 24W Output Power rent-limited pulse-frequency-modulation (PFM) control scheme gives this device the benefits of pulse-width- 110A (max) Supply Current modulation (PWM) converters (high efficiency at heavy 5A (max) Shutdown Current loads), while using less than 110A of supply current (vs. 2mA to 10mA for PWM converters). 2V to 16.5V Input Range This controller uses miniature external components. Its Preset 12V or Adjustable Output Voltage high switching frequency (up to 300kHz) allows sur- face-mount magnetics of 5mm height and 9mm diame- Current-Limited PFM Control Scheme ter. It accepts input voltages from 2V to 16.5V. The Up to 300kHz Switching Frequency output voltage is preset at 12V, or can be adjusted using two resistors. Evaluation Kit Available The MAX1771 optimizes efficiency at low input voltages and reduces noise by using a single 100mV current-limit threshold under all load conditions. A family of similar devices, the MAX770MAX773, trades some full-load efficiency for greater current-limit accuracy they provide Ordering Information a 200mV current limit at full load, and switch to 100mV for light loads. PART TEMP RANGE PIN-PACKAGE MAX1771CPA 0C to +70C 8 Plastic DIP The MAX1771 drives an external N-channel MOSFET switch, allowing it to power loads up to 24W. If less power MAX1771CSA 0C to +70C 8 SO is required, use the MAX756/MAX757 or MAX761/MAX762 MAX1771C/D 0C to +70C Dice* step-up switching regulators with on-board MOSFETs. An MAX1771EPA -40C to +85C 8 Plastic DIP evaluation kit is available. MAX1771ESA -40C to +85C 8 SO Applications MAX1771MJA -55C to +125C 8 CERDIP** * Contact factory for dice specifications. Positive LCD-Bias Generators ** Contact factory for availability and processing to MIL-STD-883B. Flash Memory Programmers Functional Diagrams High-Power RF Power-Amplifier Supply Palmtops/Hand-Held Terminals Battery-Powered Applications Portable Communicators Pin Configuration Typical Operating Circuit TOP VIEW INPUT 2V TO VOUT OUTPUT 1 8 EXT 12V CS N EXT 2 7 MAX1771 V+ GND MAX1771 ON/OFF SHDN CS 3 6 AGND FB 4 5 SHDN REF REF V+ DIP/SO FB AGND GND Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim integrated.com. 19-0263 Rev 2 3/02 AVAILABLEMAX1771 12V or Adjustable, High-Efficiency, Low I , Step-Up DC-DC Controller Q ABSOLUTE MAXIMUM RATINGS Supply Voltage Operating Temperature Ranges V+ to GND ...............................................................-0.3V, 17V MAX1771C A .....................................................0C to +70C EXT, CS, REF, SHDN, FB to GND ...................-0.3V, (V+ + 0.3V) MAX1771E A ..................................................-40C to +85C GND to AGND.............................................................0.1V, -0.1V MAX1771MJA ................................................-55C to +125C Continuous Power Dissipation (T = +70C) Junction Temperatures A Plastic DIP (derate 9.09mW/C above +70C) ............727mW MAX1771C A/E A.......................................................+150C SO (derate 5.88mW/C above +70C).........................471mW MAX1771MJA ..............................................................+175C CERDIP (derate 8.00mW/C above +70C).................640mW Storage Temperature Range .............................-65C to +160C Lead Temperature (soldering, 10sec) .............................+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+ = 5V, I = 0mA, T = T to T , unless otherwise noted. Typical values are at T = +25C.) LOAD A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS MAX1771 (internal feedback resistors) 2.0 12.5 Input Voltage Range MAX1771C/E (external resistors) 3.0 16.5 V MAX1771MJA (external resistors) 3.1 16.5 Minimum Start-Up Voltage 1.8 2.0 V Supply Current V+ = 16.5V, SHDN = 0V (normal operation) 85 110 A V+ = 10V, SHDN 1.6V (shutdown) 25 Standby Current A V+ = 16.5V, SHDN 1.6V (shutdown) 4 V+ = 2V to 12V, over full load range, Output Voltage (Note 1) 11.52 12.0 12.48 V Circuit of Figure 2a Output Voltage Line Regulation V+ = 5V to 7V, V = 12V OUT 5 mV/V (Note 2) I = 700mA, Circuit of Figure 2a LOAD Output Voltage Load Regulation V+ = 6V, V = 12V, I = 0mA to OUT LOAD 20 mV/A (Note 2) 500mA, Circuit of Figure 2a Maximum Switch On-Time t (max) 12 16 20 s ON Minimum Switch Off-Time t (min) 1.8 2.3 2.8 s OFF V+ = 5V, V = 12V, I = 500mA, OUT LOAD Efficiency 92 % Circuit of Figure 2a MAX1771C 1.4700 1.5 1.5300 Reference Voltage V I 0A MAX1771E 1.4625 1.5 1.5375 V REF REF = MAX1771M 1.4550 1.5 1.5450 MAX1771C/E 410 REF Load Regulation 0A I 100A mV REF MAX1771M 415 REF Line Regulation 3V V+ 16.5V 40 100 V/V MAX1771C 1.4700 1.5 1.5300 FB Trip Point Voltage V MAX1771E 1.4625 1.5 1.5375 V FB MAX1771M 1.4550 1.5 1.5450 2 Maxim Integrated