MAX619CSA+

The MAX619 provides a regulated 5V output from a 2V to 3.6V (two battery cells) input. Internal charge pumps and external capacitors generate the 5V output, eliminating the need for inductors. The output voltage is regulated to 5V ±4% by a pulse-skipping controller that turns on the charge pump when the output voltage begins to droop. To maintain the greatest efficiency over the entire input voltage range, the MAX619’s internal charge pump operates as a voltage doubler when VIN ranges from 3.0V to 3.6V, and as a voltage tripler when VIN ranges from 2.0V to 2.5V. When VIN ranges from 2.5V to 3.0V, the MAX619 switches between doubler and tripler mode on alternating cycles, making a 2.5×VIN charge pump. To further enhance efficiency over the input range, an internal comparator selects the higher of VIN or VOUT to run the MAX619’s internal circuitry. Efficiency with VIN = 2V and loul = 20mA is typically 80%.

Applications

• Two Battery Cells to 5V Conversion
• Local 3V-to-5V Conversion
• Portable Instruments & Handy-Terminals
• Battery-Powered Microprocessor-Based Systems
• 5V Flash Memory Programmer
• Minimum Component DC-DC Converters
• Remote Data-Acquisition Systems
• Compact 5V Op-Amp Supply
• Regulated 5V Supply from Lithium Backup Battery
• Switching Drive Voltage for MOSFETs in Low-Voltage Systems

Key features

• The MAX619 step-up charge-pump DC-DC converter delivers a regulated 5V ±4% output at 50mA over temperature.
• The input voltage range is 2V to 3.6V (two battery cells).
• The complete MAX619 circuit fits into less than 0.1 in² of board space because it requires only four external capacitors: two 0.22μF flying capacitors, and 10μF capacitors at the input and output.
• Low operating supply current (150μA max) and low shutdown supply current (1μA max) make this device ideal for small, portable, and battery-powered applications.
• When shut down, the load is disconnected from the input.
• The MAX619 is available in 8-pin DIP and SO packages.
• Regulated 5V ±4% Charge Pump
• Output Current Guaranteed over Temperature 20mA (VIN ≥ 2V) 50mA (VIN ≥ 3V)
• 2V to 3.6V Input Range
• No Inductors; Very Low EMI Noise
• Ultra-Small Application Circuit (0.1in²)
• Uses Small, Inexpensive Capacitors
• 500kHz Internal Oscillator
• Logic-Controlled 1μA Max Shutdown Supply Current
• Shutdown Disconnects Load from Input
• 8-Pin DIP and SO Packages