LT8614 42V, 4A Synchronous Step-Down Silent Switcher with 2.5A Quiescent Current FEATURES DESCRIPTION n Silent Switcher Architecture The LT 8614 step-down regulator features Silent Switcher n Ultralow EMI Emissions architecture designed to minimize EMI emissions while n High Efficiency at High Frequency delivering high efficiency at frequencies up to 3MHz. n Up to 96% Efficiency at 1MHz, 12V to 5V Assembled in a 3mm 4mm QFN, the monolithic con- IN OUT n Up to 94% Efficiency at 2MHz, 12V to 5V struction with integrated power switches and inclusion of IN OUT n Wide Input Voltage Range: 3.4V to 42V all necessary circuitry yields a solution with a minimal PCB n Ultralow Quiescent Current Burst Mode Operation: footprint. An ultralow 2.5A quiescent currentwith the n 2.5A I Regulating 12V to 3.3V output in full regulation enables applications requiring Q IN OUT n Output Ripple < 10mV highest efficiency at very small load currents. Transient P-P n Fast Minimum Switch On-Time: 30ns response remains excellent and output voltage ripple is n Low Dropout Under All Conditions: 125mV at 1A below 10mV at any load, from zero to full current. P-P n Safely Tolerates Inductor Saturation in Overload The LT8614 allows high V to low V conversion at high IN OUT n Adjustable and Synchronizable: 200kHz to 3MHz frequency with a fast minimum top switch on-time of 30ns. n Peak Current Mode Operation Operation is safe in overload even with a saturated inductor. n Accurate 1V Enable Pin Threshold n Essential features are included and easy to use: An open- Internal Compensation n drain PG pin signals when the output is in regulation. The Output Soft-Start and Tracking n SYNC pin allows clock synchronization and choice of Burst Small 18-Lead 3mm 4mm QFN n Mode operation or pulse-skipping mode. Soft-start and AEC-Q100 Qualified for Automotive Applications tracking functionality is accessed via the TR/SS pin. An accurate enable threshold can be set using the EN/UV pin APPLICATIONS and a resistor at the RT pin programs switch frequency. n All registered trademarks and trademarks are the property of their respective owners. Protected Automotive and Industrial Supplies by U.S. patents, including 8823345. n General Purpose Step-Down n GSM Power Supplies 12V to 5V Efficiency TYPICAL APPLICATION IN OUT 100 5V 4A Step-Down Converter 1MHz 95 V IN 2MHz 5.8V TO 42V 90 4.7F EN/UV V V IN1 IN2 85 1F 1F GND1 GND2 80 LT8614 PG BST 4.7H 0.1F V 75 OUT 10nF SYNC/MODE SW 5V 4A 70 TR/SS BIAS 1F 4.7pF 1M 65 47F INTV FB CC 41.2k 60 243k RT GND 2.0 2.5 0 0.5 1.0 1.5 3.0 3.5 4.0 LOAD CURRENT (A) 8614 TA01b f = 1MHz SW 8614 TA01a Rev. F 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8614 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , EN/UV, PG ..........................................................42V IN BIAS ..........................................................................30V BST Pin Above SW Pin................................................4V 20 19 18 17 FB, TR/SS, RT, INTV .............................................4V CC BIAS 1 16 TR/SS SYNC/MODE Voltage ...............................................6V INTV 2 15 RT CC Operating Junction Temperature Range (Note 2) BST 3 EN/UV 14 22 V 4 V LT8614E ............................................. 40C to 125C 13 IN1 IN2 SW LT8614I .............................................. 40C to 125C 21 GND1 6 SW 11 GND2 LT8614H ............................................ 40C to 150C 7 8 9 10 LT8614MP OBSOLETE ....................... 55C to 150C Storage Temperature Range .................. 65C to 150C UDC PACKAGE 18-LEAD (3mm 4mm) PLASTIC QFN = 40C/W, (PAD) = 12C/W (Note 3) JA JC EXPOSED PAD (PINS 21, 22) ARE SW, SHOULD BE SOLDERED TO PCB NOTE: PINS 5, 12 ARE REMOVED. CONFIGURATION DOES NOT MATCH JEDEC 20-PIN PACKAGE OUTLINE ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT8614EUDC PBF LT8614EUDC TRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 125C LT8614IUDC PBF LT8614IUDC TRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 125C LT8614HUDC PBF LT8614HUDC TRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 150C OBSOLETE LT8614MPUDC PBF LT8614MPUDC TRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 55C to 150C AUTOMOTIVE PRODUCTS** LT8614EUDC WPBF LT8614EUDC WTRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 125C LT8614IUDC WPBF LT8614IUDC WTRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 125C LT8614HUDC WPBF LT8614HUDC WTRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 150C 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 CHARACTERISTICSThe 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 Minimum Input Voltage l 2.9 3.4 V V Quiescent Current V = 0V 1.0 3 A IN EN/UV l 1.0 8 A V = 2V, Not Switching, V = 0V 1.7 4 A EN/UV SYNC l 1.7 10 A V = 2V, Not Switching, V = 2V 0.26 0.5 mA EN/UV SYNC Rev. F 2 For more information www.analog.com GND1 FB SW PG SW GND GND2 SYNC/MODE