LT3494AEDDB#TRMPBF Analog Devices

POWER LOSS (mW) LT3494/LT3494A Micropower Low Noise Boost Converters with Output Disconnect FEATURES DESCRIPTION Low Quiescent Current The LT 3494/LT3494A are low noise boost converters 65A in Active Mode with integrated power switch, Schottky diode and output 1A in Shutdown Mode disconnect circuitry. The parts use a novel* control tech- Switching Frequency is Non-Audible Over Entire nique resulting in low output voltage ripple as well as high Load Range ef ciency over a wide load current range. This technique Integrated Power NPN: guarantees that the switching frequency stays above the 350mA Current Limit (LT3494A) audio band for the entire load range. The parts feature a high 180mA Current Limit (LT3494) performance NPN power switch with a 350mA and 180mA Integrated Schottky Diode current limit for the LT3494A and LT3494 respectively. The Integrated Output Disconnect quiescent current is a low 65A, which is further reduced Integrated Output Dimming to less than 1A in shutdown. The internal disconnect Wide Input Range: 2.3V to 16V circuitry allows the output voltage to be isolated from the Wide Output Range: Up to 40V input during shutdown. An auxiliary reference input (CTRL Tiny 8-Lead 3mm 2mm DFN Package pin) overrides the internal 1.225V feedback reference with any lower value allowing full control of the output voltage APPLICATIONS during operation. The LT3494/LT3494A are available in a tiny 8-lead 3mm 2mm DFN package. OLED Power , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Low Noise Power All other trademarks are the property of their respective owners. *Patent pending. MP3 Players TYPICAL APPLICATION Output Voltage Ripple Ef ciency and Power Loss vs Load Current vs Load Current OLED Power Supply from One Li-Ion Cell 15 90 280 V = 3.6V LT3494 IN LOAD FROM FIGURE 5 CIRCUIT CAPACITOR 80 240 15H V 100MHz MEASUREMENT BW IN 3V LOAD FROM 70 200 TO 4.2V 4.7F 0.22F V OUT 10 SW CAP V OUT 60 160 V V 16V CC OUT 16mA LT3494 2.21M 50 120 2.2F SHDN FB 5 40 80 CTRL GND 3494 TA01a 30 40 20 0 0 0.1 1 10 100 0.1 1 10 100 LOAD CURRENT (mA) LOAD CURRENT (mA) 3494 TA01c 3494 TA01b 3494fb 1 V PEAK-TO-PEAK RIPPLE (mV) OUT EFFICIENCY (%)LT3494/LT3494A ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Note 1) TOP VIEW V Voltage ...............................................................16V CC SW Voltage ...............................................................40V SW 1 8 CAP GND 2 7 V CAP Voltage ..............................................................40V OUT 9 V FB 3 6 CC V Voltage .............................................................40V OUT CTRL 4 5 SHDN SHDN Voltage ...........................................................16V CTRL Voltage ............................................................16V DDB PACKAGE FB Voltage ................................................................2.5V 8-LEAD (3mm 2mm) PLASTIC DFN T = 125C, = 76C/W JMAX JA Maximum Junction Temperature .......................... 125C EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB Operating Temperature Range (Note 2) ... 40C to 85C ORDER PART NUMBER DDB PART MARKING Storage Temperature Range ................... 65C to 125C LT3494EDDB LCCD LT3494AEDDB LCRW Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: