Features: 90% Efficiency for 10mA to 1A Load Currents
Up to 15W Output Power
110A Max Supply Current
5A Max Shutdown Current
2V to 16.5V Input Range (MAX770/MAX771/MAX772)
Internal Shunt Regulator for High Input Voltages (MAX773)
Preset or Adjustable Output Voltages:
MAX770: 5V or Adjustable
MAX771: 12V or Adjustable
MAX772: 15V or Adjustable
MAX773: 5V, 12V, 15V, or Adjustable
Current-Limited PFM Control Scheme
300kHz Switching FrequencyApplicationPalmtops/Handy-Terminals
High-Efficiency DC-DC Converters
Battery-Powered Applications
Positive LCD-Bias Generators
Portable Communicators
Flash Memory ProgrammersPinout
SpecificationsABSOLUTE MAXIMUM RATINGS
Supply Voltages
V+ to GND............................................................-0.3V to 17V
V+ to SGND............................................................-0.3V to 7V
SGND........................................................-0.3V to (V+ + 0.3V)
EXT, CS, REF, LBO, LBI, SHDN, FB.............-0.3V to (V+ + 0.3V)
EXTH, EXTL ..............................................-0.3V to (V+ + 0.3V)
V5, V12, V15 ........................................................-0.3V to 17V
GND to AGND ......................................................0.1V to -0.1V
ISGND .............................................................................50mA
Continuous Power Dissipation (TA = +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)..727mW
8-Pin SO (derate 5.88mW/°C above +70°C) .............471mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C) ......640mW
14-Pin Plastic DIP
(derate 10.00mW/°C above +70°C) ..........................800mW
14-Pin SO (derate 8.33mW/°C above +70°C) ...........667mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C).....727mW
Operating Temperature Ranges
MAX77_C__ ......................................................0°C to +70°C
MAX77_E__....................................................-40°C to +85°C
MAX77_MJ_ .................................................-55°C to +125°C
Junction Temperatures
MAX77_C__/E__ .........................................................+150°C
MAX77_MJ_..................................................................+175°C
Storage Temperature Range........................-65°C to +160°C
Lead Temperature (soldering, 10sec) .........................+300°C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. hese 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.
DescriptionThe MAX770MAX773 step-up switching controllers provide 90% efficiency over a 10mA to 1A load. A unique current-limited pulse-frequency-modulation (PFM) control scheme gives these devices the benefits of pulse-width-modulation (PWM) converters (high efficiency at heavy loads), while using less than 110A of supply current (vs. 2mA to 10mA or PWM converters).
These ICs MAX773 use tiny external components. Their high switching frequencies (up to 300kHz) allow surfacemount magnetics of 5mm height and 9mm diameter.
The MAX770/MAX771/MAX772 accept input voltages from 2V to 16.5V. Output voltages are preset at 5V, (MAX770), 12V (MAX771), and 15V (MAX772); they can also be adjusted using two resistors.
The MAX773 accepts inputs from 3V to 16.5V. For a wider input range, it features an internal shunt regulator that allows unlimited higher input voltages. The MAX773's output can be set to 5V, 12V, or 15V, or it can be adjusted with two resistors.
The MAX770MAX773 drive external N-channel MOSFET switches, allowing them to power loads up to 15W. If less power is required, use the MAX756/MAX757 or MAX761/MAX762 step-up switching regulators with onboard MOSFETs.
MAX773 Data Sheet
