LT3471 Dual 1.3A, 1.2MHz Boost/Inverter in 3mm × 3mm DFN FEATURESDESCRIPTION n 1.2MHz Switching Frequency The LT®3471 dual switching regulator combines two 42V, n Low VCESAT Switches: 330mV at 1.3A 1.3A switches with error amplifi ers that can sense to n High Output Voltage: Up to 40V ground providing boost and inverting capability. The low n Wide Input Range: 2.4V to 16V VCESAT bipolar switches enable the device to deliver high n Inverting Capability current outputs in a small footprint. The LT3471 switches n 5V at 630mA from 3.3V Input at 1.2MHz, allowing the use of tiny, low cost and low profi le n 12V at 320mA from 5V Input inductors and capacitors. High inrush current at start-up n –12V at 200mA from 5V Input is eliminated using the programmable soft-start function, n Uses Tiny Surface Mount Components where an external RC sets the current ramp rate. A constant n Low Shutdown Current: < 1μA frequency current mode PWM architecture results in low, n Low Profi le (0.75mm) 10-Lead 3mm × 3mm predictable output noise that is easy to fi lter. DFN Package The LT3471 switches are rated at 42V, making the device APPLICATIONS ideal for boost converters up to ±40V as well as SEPIC and fl yback designs. Each channel can generate 5V at n Organic LED Power Supply up to 630mA from a 3.3V supply, or 5V at 510mA from n Digital Cameras four alkaline cells in a SEPIC design. The device can be n White LED Power Supply confi gured as two boosts, a boost and inverter or two n Cellular Phones inverters. n Medical Diagnostic Equipment The LT3471 is available in a low profi le (0.75mm) 10-lead n Local ±5V or ±12V Supply 3mm × 3mm DFN package. n TFT-LCD Bias Supply L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. n xDSL Power Supply All other trademarks are the property of their respective owners. TYPICAL APPLICATIONOLED DriverOLED Driver Effi ciency 2.2μH V V OUT1 IN 95 7V 3.3V 350mA 90.9k 4.7μF 90 V CONTROL 1 OUT1 = 7V 4.7k SW1 SHDN/SS1 FB1N 85 0.33μF FB1P 15k 80 VOUT1 = –7V VREF 75 V 0.1μF IN VIN LT3471 70 10μF 15k FB2N EFFICIENCY (%) 65 CONTROL 2 4.7k SHDN/SS2 FB2P 60 0.33μF GND SW2 55 3471 TA01 105k 75pF 1μF 10μH 15μH 50 VOUT2 0 100 200 300 400 V –7V IN I 250mA OUT (mA) 10μF 3471 TA01b 3471fb 1
