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 n AEC-Q100 Qualified for Automotive Applications low thermal resistance. All registered trademarks and trademarks are the property of their respective owners. APPLICATIONS n Automotive and Industrial Supplies n General Purpose Step-Down n GSM Power Supplies TYPICAL APPLICATION Efficiency at 5V OUT 5V 6A Step-Down Converter 100 V V = 12V IN IN V BST IN 5.6V TO 42V 95 0.1F 10F EN/UV 3.9H V = 24V V IN OUT 90 5V PG SW LT8612 6A 100F 85 SYNC BIAS 1210 10nF 1M 80 TR/SS FB 1F 10pF 75 INTV CC 70 RT PGND GND 65 f = 700kHz 60.4k 243k SW L = 3.9H 60 0 1 2 3 4 5 6 f = 700kHz SW 8612 TA01a LOAD CURRENT (A) L: EPCOS B82559 8612 TA01b Rev. B 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8612 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , EN/UV, PG ..........................................................42V IN BIAS ..........................................................................25V 28 27 26 25 FB, TR/SS ................................................................4V SYNC 1 24 FB SYNC Voltage ...........................................................6V TR/SS 2 23 PG Operating Junction Temperature Range (Note 2) RT 3 22 BIAS LT8612E ............................................. 40C to 125C EN/UV 4 21 INTV CC LT8612I .............................................. 40C to 125C V 5 20 BST 29 IN GND Storage Temperature Range .................. 65C to 150C 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 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT8612EUDE PBF LT8612EUDE TRPBF LGHW 28-Lead (3mm 6mm) Plastic QFN 40C to 125C LT8612IUDE PBF LT8612IUDE TRPBF LGHW 28-Lead (3mm 6mm) Plastic QFN 40C to 125C AUTOMOTIVE PRODUCTS** LT8612EUDE WPBF LT8612EUDE WTRPBF LGHW 28-Lead (3mm 6mm) Plastic QFN 40C to 125C LT8612IUDE WPBF LT8612IUDE WTRPBF LGHW 28-Lead (3mm 6mm) Plastic QFN 40C to 125C Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. **Versions of this part are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These models are designated with a W suffix. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for thesemodels. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. A PARAMETER CONDITIONS MIN TYP MAX UNITS l Minimum Input Voltage 2.9 3.4 V V Quiescent Current V = 0V, V = 0V 1.0 5 A IN EN/UV SYNC l 1.0 20 A V = 2V, Not Switching, V = 0V 1.7 6 A EN/UV SYNC l 1.7 20 A V = 2V, Not Switching, V = 2V 0.3 0.6 mA EN/UV SYNC Rev. B 2 For more information www.analog.com GND NC GND NC GND NC GND NC