onsemi NCP1522BMUTBG

The NCP1522B step−down DC−DC converter is a monolithic integrated circuit optimized for portable applications powered from one cell Li−Ion or three cell Alkaline/NiCd/NiMH batteries. The part, available in adjustable output voltage versions ranging from 0.9 V to 3.3 V, is able to deliver up to 600 mA. It uses synchronous rectification to increase efficiency and reduce external part count. The device also has a built−in 3 MHz (nominal) oscillator which reduces component size by allowing smaller inductors and capacitors. Automatic switching PWM/PFM mode offers improved system efficiency. The NCP1522B uses a constant frequency, voltage mode step−down architecture. Both the main (P−Channel MOSFET) and synchronous (N−Channel MOSFET) switches are internal. The output voltage is set by an external resistor divider in the range of 0.9 V to 3.3 V and can source at least 600 mA. The NCP1522B works with two modes of operation; PWM/PFM depending on the current required. In PWM mode, the device can supply voltage with a tolerance of ± 3% and 90% efficiency or better. Lighter load currents cause the device to automatically switch into PFM mode to reduce current consumption and extended battery life. Additional features include soft−start, undervoltage protection, current overload protection, and thermal shutdown protection. Only six external components are required. The part uses an internal reference voltage of 0.6 V. It is recommended to keep NCP1522B in shutdown mode until the input voltage is 2.7 V or higher.

• Up to 93% Efficiency
• Allow Use of Small External Components
• Source up to 600 mA
• 3 MHz Switching Frequency
• Adjustable Output Voltage from 0.9 V to 3.3 V
• Synchronous Rectification for Higher Efficiency
• 2.7 V to 5.5 V Input Voltage Range
• Low Quiescent Current
• Shutdown Current Consumption of 0.3 μA
• Thermal Limit Protection
• Short Circuit Protection
• All Pins are Fully ESD Protected
• These are Pb−Free Devices

• Cellular Phones, Smart Phones and PDAs
• Digital Still/Video Cameras
• MP3 Players and Portable Audio Systems
• Wireless and DSL Modems
• Portable Equipment
• USB Powered Devices