Home > Products > Micropower, Low Noise Boost Converters with Integrated Schottky Diode

Power

Micropower, Low Noise Boost Converters with Integrated Schottky Diode

2nd June 2007

ES Admin

0 0

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