Micropower, Low Noise Boost Converters with Integrated Schottky Diode in 3mm x 2mm DFN Package

Date Announced: 13 Mar 2007 Linear Technology has announced the LT3494/A low noise boost converters with integrated power switches, Schottky diodes and output disconnect circuitry. The LT3494 uses a 180mA switch, the LT3494A uses a 350mA switch, and both parts are packaged in a 3mm x 2mm DFN-8 package. Their wide 2.3V to 16V input voltage range enables operation from single cell Li-Ion batteries up to fixed 12V input rails, delivering outputs up to 40V. The LT3494 can deliver over 17mA of current at 15V from a single Li-Ion cell, making it ideal for applications such as OLED displays. The LT3494A has higher current capability and can deliver over 27mA of current at 15V from a single Li-Ion cell. Both parts use a unique control technique that delivers both high efficiency and low output ripple over a wide load current range. This technique guarantees that the switching frequency stays above the audio band for the entire load range, making it ideal for noise-sensitive applications such as MP3 players. The combination of the LT3494/A's 3mm x 2mm DFN package and tiny, low cost ceramic capacitors and inductors provides a very compact solution footprint.The LT3494's NPN switch achieves a VCESAT of only 110mV at 100mA, offering efficiencies as high as 80%. Only 65uA of quiescent current (<1uA in shutdown) maximizes battery run-time while integrated Schottky diodes and output disconnect circuitry eliminates costly external circuitry. Finally, an integrated dimming/contrast adjustment function is included for display applications. The LT3494EDDB and LT3494AEDDB are both available from stock in an 8-lead 3mm x 2mm DFN package. Pricing starts at $1.45 each for 1,000-piece quantities.Summary of Features of the LT3494/A:• Low Quiescent Current: 65 uA in Active Mode (0.1uA in Shutdown Mode)• Switching Frequency is Non-Audible Over Entire Load Range• Integrated Power NPN:­ 350mA Current Limit (LT3494A)­ 180mA Current Limit (LT3494)• Integrated Schottky Diode• Integrated Output Disconnect• Integrated Output Dimming• Wide Input Range: 2.3V to 16V• Wide Output Range: Up to 40V• Tiny 8-Lead 3mm x 2mm DFN Package

Contact
UK, Ireland, South Africa and Israel: Alastair Boyd, Linear Technology (UK) Limited Tel: +44 (0)1628 477066 E-mail: [email protected] North America and General Information: Doug Dickinson, Linear Technology Corporation Tel: (408) 432 1900 ext. 2233 E-mail: [email protected]

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