LT3494A Datasheet | Linear Technology

LT3494/LT3494A Micropower Low Noise Boost Converters with Output Disconnect Features - DESCRIPTION The LT®3494/LT3494A are low noise boost converters with integrated power switch, Schottky diode and output disconnect circuitry. The parts use a novel- control technique resulting in low output voltage ripple as well as high efficiency over a wide load current range. This technique guarantees that the switching frequency stays above the audio band for the entire load range. The parts feature a high performance NPN power switch with a 350m A and 180m A current limit for the LT3494A and LT3494 respectively. The quiescent current is a low 65μA, which is further reduced to less than 1μA in shutdown. The internal disconnect circuitry allows the output voltage to be isolated from the input during shutdown. An auxiliary reference input (CTRL pin) overrides the internal 1.225V feedback reference with any lower value allowing full control of the output voltage during operation. The LT3494/LT3494A are available in a tiny 8-lead 3mm × 2mm DFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. - Patent pending. - - - - - - - - Low Quiescent Current 65μA in Active Mode 1μA in Shutdown Mode Switching Frequency is Non-Audible Over Entire Load Range Integrated Power NPN: 350m A Current Limit (LT3494A) 180m A 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 × 2mm DFN Package APPLICATIONS - - - OLED Power Low Noise Power MP3 Players .. TYPICAL APPLICATION OLED Power Supply from One Li-Ion Cell VIN 3V TO 4.2V 15μH 4.7μF SW VCC SHDN CTRL CAP VOUT 2.21M FB GND 3494 TA01a Output Voltage Ripple vs Load Current 15 VOUT PEAK-TO-PEAK RIPPLE (m V) LT3494 FIGURE 5 CIRCUIT 100MHz MEASUREMENT BW EFFICIENCY (%) 90 80 70 60 50 40 30 0 0.1 1 10 LOAD...