LT8612 42V, 6A Synchronous Step-Down Regulator with 3A Quiescent Current FEATURES DESCRIPTION n Wide Input Voltage Range: 3.4V to 42V The LT 8612 is a compact, high efficiency, high speed n Ultralow Quiescent Current Burst Mode Operation: synchronous monolithic step-down switching regulator n 3A I Regulating 12V to 3.3V that consumes only 3A of quiescent current. Top and Q IN OUT n Output Ripple < 10mV bottom power switches are included with all necessary P-P n High Efficiency Synchronous Operation: circuitry to minimize the need for external components. n 95% Efficiency at 3A, 5V from 12V Low ripple Burst Mode operation enables high efficiency OUT IN n 94% Efficiency at 3A, 3.3V from 12V down to very low output currents while keeping the output OUT IN n Fast Minimum Switch-On-Time: 40ns ripple below 10mV . A SYNC pin allows synchronization P-P n Low Dropout Under All Conditions: 250mV at 3A to an external clock. Internal compensation with peak cur- n Allows Use of Small Inductors rent mode topology allows the use of small inductors and n Safely Tolerates Inductor Saturation in Overload results in fast transient response and good loop stability. Conditions The EN/UV pin has an accurate 1V threshold and can be n Adjustable and Synchronizable: 200kHz to 2.2MHz used to program V undervoltage lockout or to shut down IN n Current Mode Operation the LT8612 reducing the input supply current to 1A. A n Accurate 1V Enable Pin Threshold capacitor on the TR/SS pin programs the output voltage n Internal Compensation ramp rate during start-up. The PG flag signals when V OUT n Output Soft-Start and Tracking is within 9% of the programmed output voltage as well n Small Thermally Enhanced 3mm 6mm 28-Lead as fault conditions. The LT8612 is available in a small QFN Package 3mm 6mm 28-lead QFN package with exposed pad for low thermal resistance. APPLICATIONS L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. n Automotive and Industrial Supplies n General Purpose Step-Down n GSM Power Supplies TYPICAL APPLICATION Efficiency at 5V OUT 100 5V 6A Step-Down Converter V = 12V IN 95 V IN V BST IN 5.6V TO 42V V = 24V IN 0.1F 10F 90 EN/UV 3.9H V OUT 5V PG SW 85 LT8612 6A 100F SYNC BIAS 1210 80 10nF 1M TR/SS FB 75 1F 10pF 70 INTV CC RT PGND GND 65 f = 700kHz SW L = 3.9H 60.4k 243k 60 0 1 2 3 4 5 6 LOAD CURRENT (A) f = 700kHz SW 8612 TA01a 8612 TA01b L: EPCOS B82559 8612fa 1 For more information www.linear.com/LT8612 EFFICIENCY (%)LT8612 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) V , EN/UV, PG ..........................................................42V TOP VIEW IN BIAS ..........................................................................25V FB, TR/SS . .................................................................4V 28 27 26 25 SYNC Voltage . ............................................................6V SYNC 1 24 FB Operating Junction Temperature Range (Note 2) TR/SS 2 23 PG RT 3 22 BIAS LT8612E ............................................. 40C to 125C EN/UV 4 21 INTV CC LT8612I .............................................. 40C to 125C V 5 20 BST IN 29 Storage Temperature Range .................. 65C to 150C GND V 6 19 SW IN V 7 18 SW IN PGND 8 17 SW PGND 9 16 SW PGND 10 15 SW 11 12 13 14 UDE PACKAGE 28-LEAD (3mm 6mm) PLASTIC QFN = 40C/W, = 5C/W JA JC(PAD) EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB