1A, 97% Efficiency, 30µA Quiescent Current Step-Up Converter with True Shutdown
General Description The MAX8815A DC-DC step-up converter is a high-effi- ciency, low quiescent current, synchronous step-up converter with True Shutdown™ and inrush-current lim- iting. The MAX8815A generates any output voltage from 3.3V to 5V from a 2-cell NiMH/NiCd or a single-cell Li+/Li polymer battery. The MAX8815A uses two modes of operation. The first mode of operation (normal) uses only 30µA (typ) quies- cent current and allows the converter to switch only when needed at no load and light loads. Under moder- ate and heavy loads (typically above 90mA), the MAX8815A uses a fixed-frequency pulse-width modula- tion (PWM) technique. This mode allows maximum effi- ciency at light loads. The second mode of operation is a fixed-frequency forced-pulse-width modulation (FPWM) mode where the converter switches at a fixed frequency irrespective of the load. This mode allows for easy noise filtering and lower output ripple. The MAX8815A has a preset 2.5A current limit, allowing 500mA load at 1.8V input and 1A load at 2.5V input when the output is set to 5V. Features include soft-start, which limits inrush current during startup, True Shutdown, and internal compensation. The MAX8815A is available in a compact 10-pin, 3mm x 3mm TDFN package. The MAX8815A evaluation kit can help shorten the time required for system design.
Applications DSC and DVC Microprocessor/DSP Core Power Cell Phones, PDAs, MP3 Players Portable Handheld Devices PCMCIA Cards
Features ♦ Up to 97% Efficiency with Internal Synchronous Rectifier ♦ Low 30µA Quiescent Current ♦ Guaranteed 500mA Output Current at VOUT = 5V from 1.8V Input ♦ Guaranteed 1A Output Current at 5V from 2.5V Input ♦ Low-Noise Constant Frequency Operation (FPWM Mode) ♦ 2MHz PWM Switching Frequency ♦ Preset (5V) or Adjustable Output ♦ Controlled Current in Soft-Start Limits Inrush Current ♦ True Shutdown ♦ Internal Compensation ♦ Overload/Short-Circuit Protection ♦ 0.1µA Shutdown Current ♦ Thermal Shutdown ♦ Compact 10-Pin, 3mm x 3mm TDFN Package
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