MAX770MAX773 19-0202 Rev 2 11/96 5V/12V/15V or Adjustable, High-Efficiency, Low I , Step-Up DC-DC Controllers Q General Description Features The MAX770MAX773 step-up switching controllers pro- 90% Efficiency for 10mA to 1A Load Currents vide 90% efficiency over a 10mA to 1A load. A Up to 15W Output Power unique current-limited pulse-frequency-modulation (PFM) control scheme gives these devices the benefits of 110A Max Supply Current pulse-width-modulation (PWM) converters (high efficiency 5A Max Shutdown Current at heavy loads), while using less than 110A of supply current (vs. 2mA to 10mA for PWM converters). 2V to 16.5V Input Range These ICs use tiny external components. Their high (MAX770/MAX771/MAX772) switching frequencies (up to 300kHz) allow surface- Internal Shunt Regulator for High Input Voltages mount magnetics of 5mm height and 9mm diameter. (MAX773) The MAX770/MAX771/MAX772 accept input voltages from 2V to 16.5V. Output voltages are preset at 5V, Preset or Adjustable Output Voltages (MAX770), 12V (MAX771), and 15V (MAX772) they can MAX770: 5V or Adjustable also be adjusted using two resistors. MAX771: 12V or Adjustable The MAX773 accepts inputs from 3V to 16.5V. For a wider MAX772: 15V or Adjustable input range, it features an internal shunt regulator that MAX773: 5V, 12V, 15V, or Adjustable allows unlimited higher input voltages. The MAX773s out- Current-Limited PFM Control Scheme put can be set to 5V, 12V, or 15V, or it can be adjusted with two resistors. 300kHz Switching Frequency The MAX770MAX773 drive external N-channel MOSFET switches, allowing them to power loads up to 15W. If less Ordering Information power is required, use the MAX756/MAX757 or PART TEMP. RANGE PIN-PACKAGE MAX761/MAX762 step-up switching regulators with on- MAX770CPA 0C to +70C Plastic DIP board MOSFETs. MAX770CSA 0C to +70C 8 SO Applications MAX770C/D 0C to +70C Dice* Palmtops/Handy-Terminals MAX770EPA -40C to +85C 8 Plastic DIP High-Efficiency DC-DC Converters MAX770ESA -40C to +85C 8 SO MAX770MJA -55C to +125C 8 CERDIP** Battery-Powered Applications Ordering Information continued at end of data sheet. Positive LCD-Bias Generators *Contact factory for dice specifications. Portable Communicators **Contact factory for availability and processing to MIL-STD-883B. Flash Memory Programmers Pin Configurations Typical Operating Circuit TOP VIEW INPUT 2V TO V OUT 1 8 EXT CS OUTPUT 2 12V V+ 7 GND MAX770 N EXT MAX771 MAX771 3 6 AGND FB ON/OFF SHDN MAX772 CS 4 5 REF SHDN REF DIP/SO V+ FB AGND GND Pin Configurations continued at end of data sheet. Maxim Integrated Products 1 For free samples & the latest literature: 5V/12V/15V or Adjustable, High-Efficiency, Low I , Step-Up DC-DC Controllers Q ABSOLUTE MAXIMUM RATINGS Supply Voltages 14-Pin Plastic DIP V+ to GND.............................................................-0.3V to 17V (derate 10.00mW/C above +70C) .............................800mW V+ to SGND.............................................................-0.3V to 7V 14-Pin SO (derate 8.33mW/C above +70C) ..............667mW SGND........................................................-0.3V to (V+ + 0.3V) 14-Pin CERDIP (derate 9.09mW/C above +70C)......727mW EXT, CS, REF, LBO, LBI, SHDN, FB.............-0.3V to (V+ + 0.3V) Operating Temperature Ranges EXTH, EXTL ..................................................-0.3V to (V+ + 0.3V) MAX77 C ........................................................0C to +70C V5, V12, V15 .............................................................-0.3V to 17V MAX77 E ......................................................-40C to +85C GND to AGND .........................................................0.1V to -0.1V MAX77 MJ ...................................................-55C to +125C I ..................................................................................50mA Junction Temperatures SGND Continuous Power Dissipation (T = +70C) MAX77 C /E ..........................................................+150C A 8-Pin Plastic DIP (derate 9.09mW/C above +70C)....727mW MAX77 MJ ..................................................................+175C 8-Pin SO (derate 5.88mW/C above +70C) ................471mW Storage Temperature Range.............................-65C to +160C 8-Pin CERDIP (derate 8.00mW/C above +70C) ........640mW 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 MAX770772 (internal feedback resistors) 2.0 16.5 MAX770772C/E (external resistors) 3.0 16.5 Input Voltage Range MAX770772MJA (external resistors) 3.1 16.5 V MAX773C/E 3.0 16.5 MAX773MJD 3.1 16.5 Minimum Start-Up Voltage MAX770/MAX771/MAX772 1.8 2.0 V m A Supply Current V+ = 16.5V, SHDN = 0V (normal operation) 85 110 V+ = 10.0V, SHDN 1.6V (shutdown) 2 5 m A Standby Current V+ = 16.5V, SHDN 1.6V (shutdown) 4 V+ = 2.0V to 5.0V, over full load range 4.80 5.0 5.20 Output Voltage (Note 1) V+ = 2.0V to 12.0V, over full load range 11.52 12.0 12.48 V V+ = 2.0V to 15.0V, over full load range 14.40 15.0 15.60 Output Voltage Line Regulation Figure 2a, V+ = 2.7V to 4.5V, 5 mV/V (Note 2) I = 700mA, V = 5V LOAD OUT Output Voltage Load Regulation Figure 2a, V+ = 3V, I = 30mA to 1A, LOAD 20 mV/A (Note 2) V = 5V OUT m s Maximum Switch On-Time t (max) 12 16 20 ON Minimum Switch Off-Time t (min) 1.8 2.3 2.8 m s OFF Efficiency V+ = 4V, I = 500mA, V = 5V 87 % LOAD OUT MAX77 C 1.4700 1.5 1.5300 I 0m A Reference Voltage V REF = MAX77 E 1.4625 1.5 1.5375 V REF MAX77 M 1.4550 1.5 1.5450 2 MAX770MAX773