EVALUATION KIT AVAILABLE MAX1771 AVAILABLE 12V or Adjustable, High-Efficiency,Low IQ, Step-Up DC-DC ControllerGeneral DescriptionFeatures 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- rent-limited pulse-frequency-modulation (PFM) control ♦ Up to 24W Output Power scheme gives this device the benefits of pulse-width- ♦ 110µA (max) Supply Current modulation (PWM) converters (high efficiency at heavy loads), while using less than 110µA of supply current (vs. ♦ 5µA (max) Shutdown Current 2mA to 10mA for PWM converters). ♦ 2V to 16.5V Input Range This controller uses miniature external components. Its high switching frequency (up to 300kHz) allows sur- ♦ Preset 12V or Adjustable Output Voltage 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 output voltage is preset at 12V, or can be adjusted ♦ Up to 300kHz Switching Frequency 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 MAX770–MAX773, 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. PARTTEMP RANGEPIN-PACKAGE The MAX1771 drives an external N-channel MOSFET MAX1771CPA 0°C to +70°C 8 Plastic DIP switch, allowing it to power loads up to 24W. If less power MAX1771CSA 0°C to +70°C 8 SO is required, use the MAX756/MAX757 or MAX761/MAX762 MAX1771C/D 0°C to +70°C Dice* step-up switching regulators with on-board MOSFETs. An MAX1771EPA -40°C to +85°C 8 Plastic DIP evaluation kit is available. MAX1771ESA -40°C to +85°C 8 SO Applications MAX1771MJA -55°C to +125°C 8 CERDIP** Positive LCD-Bias Generators * Contact factory for dice specifications. ** 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 ConfigurationTypical Operating Circuit TOP VIEW INPUT 2V TO VOUT OUTPUT 12V EXT 1 8 CS EXT N 2 MAX1771 V+ 7 GND MAX1771 ON/OFF SHDN CS 3 6 FB AGND 4 5 SHDN REF REF V+ FB AGND GND DIP/SOPin 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 Maxim’s website at www.maximintegrated.com. 19-0263; Rev 2; 3/02
