DC670A Analog Devices

LT3462/LT3462A Inverting 1.2MHz/2.7MHz DC/DC Converters with Integrated Schottky FEATURES DESCRIPTION n Integrated Schottky Rectifier The LT 3462/LT3462A are general purpose fixed fre n Fixed Frequency 1.2MHz/2.7MHz Operation quency current mode inverting DC/DC converters. Both n Very Low Noise: 1mV Output Ripple devices feature an integrated Schottky and a low V P-P CESAT n Low V Switch: 270mV at 250mA switch allowing a small converter footprint and lower CESAT n 5V at 100mA from 5V Input parts cost. The LT3462 switches at 1.2MHz while the n 12V at 30mA from 3.3V Input LT3462A switches at 2.7MHz. These high speeds enable n Low Input Bias Current GND Based FB Input the use of tiny, low cost and low height capacitors and n Low Impedance (40) 1.265V Reference Output inductors. n High Output Voltage: Up to 38V The LT3462/LT3462A operate in a dual inductor inverting n Wide Input Range: 2.5V to 16V topology that filters both the input and output currents. n Uses Tiny Surface Mount Components Very low output voltage ripple approaching 1mV can PP n Low Shutdown Current: <10A be achieved when ceramic capacitors are used. Fixed fre n Low Profile (1mm) SOT 23 (ThinSOT) Package quency switching ensures a clean output free from low n 8 Lead DFN (2mm 2mm 0.75mm) Package, frequency noise typically present with charge pump solu LT3462A Only tions. The 40V switch allows a V to V differential of IN OUT up to 38V for dual inductor topologies. APPLICATIONS Both devices provide a low impedance 1.265V reference output to supply the feedback resistor network. A ground n CCD Bias referenced, high impedance FB input allows high feedback n LCD Bias resistor values without compromising output accuracy. n GaAs FET Bias All registered trademarks and trademarks are the property of their respective owners. n General Purpose Negative Voltage Supply TYPICAL APPLICATION 5V to 5V, 100mA Inverting DC/DC Converter Efficiency 75 1F T = 25C A 22H 22H V = 5V V IN IN 5V 70 V OUT 5V V = 3.3V IN 100mA 267k 22pF SW D 65 V FB IN 1F 10F LT3462A 68.1k SDREF 60 GND 3462 TA01 55 0 20 40 60 80 100 3462 TA01b LOAD CURRENT (mA) Rev A 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT3462/LT3462A ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage (V ) ....................................................16V Maximum Junction Temperature .......................... 125C IN SW Voltage ...............................................................40V Storage Temperature Range .................. 65C to 150C D Voltage ............................................................... 40V Lead Temperature (Soldering, 10sec) SDREF, FB Voltage ...................................................2.5V (TSOT 23 Package Only) ...................................300C Operating Ambient Temperature Range (Note 3) ................40C to 85C PIN CONFIGURATION TOP VIEW TOP VIEW FB 1 8 SDREF SW 1 6 V IN GND 2 7 D 9 GND 2 5 D GND 3 6 NC FB 3 4 SDREF SW 4 5 V IN S6 PACKAGE 6-LEAD PLASTIC TSOT-23 DC PACKAGE (LT3462A ONLY) 8-LEAD (2mm 2mm) PLASTIC DFN T = 125C, = 192C/W JMAX JA T = 125C, = 88.5C/W JMAX JA EXPOSED PAD (PIN 9) IS GND ORDER INFORMATION