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