LT8614 42V, 4A Synchronous Step-Down Silent Switcher with 2.5A Quiescent Current Fea T Descrip T n Silent Switcher Architecture: The LT 8614 step-down regulator features Silent Switcher Ultralow EMI/EMC Emissions architecture designed to minimize EMI/EMC emissions n High Efficiency at High Frequency while delivering high efficiency at frequencies up to 3MHz. Up to 96% Efficiency at 1MHz Assembled in a 3mm 4mm QFN, the monolithic construc- Up to 94% Efficiency at 2MHz tion with integrated power switches and inclusion of all n Wide Input Voltage Range: 3.4V to 42V necessary circuitry yields a solution with a minimal PCB n Ultralow Quiescent Current Burst Mode Operation: footprint. An ultralow 2.5A quiescent currentwith the 2.5A I Regulating 12V to 3.3V output in full regulation enables applications requiring Q IN OUT 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: 200mV 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 IN OUT n Adjustable and Synchronizable: 200kHz to 3MHz high frequency with a fast minimum top switch on-time of n Peak Current Mode Operation 30ns. Operation is safe in overload even with a saturated n Accurate 1V Enable Pin Threshold inductor. n Internal Compensation n Essential features are included and easy to use: An open- Output Soft-Start and Tracking n drain PG pin signals when the output is in regulation. The Small 18-Lead 3mm 4mm QFN SYNC pin allows clock synchronization and choice of Burst Mode operation or pulse-skipping mode. Soft-start and a T tracking functionality is accessed via the TR/SS pin. An accurate enable threshold can be set using the EN/UV pin n Automotive and Industrial Supplies and a resistor at the RT pin programs switch frequency. n General Purpose Step-Down n L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks GSM Power Supplies and Silent Switcher is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical a T 12V to 5V Efficiency IN OUT 5V 4A Step-Down Converter 100 1MHz V IN 95 5.8V TO 42V 2MHz 4.7F EN/UV 90 V V IN1 IN2 1F 1F 85 GND1 GND2 LT8614 80 PG BST 4.7H 0.1F V OUT 10nF SYNC/MODE SW 5V 75 4A TR/SS BIAS 70 1F 4.7pF 1M 47F INTV FB CC 65 41.2k 243k RT GND 60 2.0 2.5 0 0.5 1.0 1.5 3.0 3.5 4.0 f = 1MHz LOAD CURRENT (A) SW 8614 TA01a 8614 TA01b 8614fb 1 For more information www.linear.com/LT8614 EFFICIENCY (%) ion pplica ions pplica ion uresLT8614 a Te Maxi Mu M r a T p c F T (Note 1) TOP VIEW V , EN/UV, PG ..........................................................42V IN BIAS ..........................................................................30V BST Pin Above SW Pin................................................4V FB, TR/SS, RT, INTV .............................................4V 20 19 18 17 CC SYNC Voltage ...........................................................6V 1 16 BIAS TR/SS Operating Junction Temperature Range (Note 2) INTV 2 15 RT CC LT8614E ............................................. 40C to 125C BST 3 EN/UV 14 LT8614I .............................................. 40C to 125C 22 V 4 VIN2 13 IN1 SW LT8614H ............................................ 40C to 150C 21 Storage Temperature Range .................. 65C to 150C GND1 6 SW 11 GND2 7 8 9 10 UDC PACKAGE 18-LEAD (3mm 4mm) PLASTIC QFN = 40C/W, = 12C/W JA JC(PAD) 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 o r D i n F Ma T 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 40C to 125C 18-Lead (3mm 4mm) Plastic QFN LT8614HUDC PBF LT8614HUDC TRPBF LGGQ 18-Lead (3mm 4mm) Plastic QFN 40C to 150C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: