POWER LOSS (mW) LT3970 Series 40V, 350mA Step-Down Regulator with 2.5A Quiescent Current and Integrated Diodes Fea T Descrip T n Low Ripple Burst Mode Operation The LT 3970 is an adjustable frequency monolithic buck 2.5A I at 12V to 3.3V switching regulator that accepts a wide input voltage Q IN OUT Output Ripple < 5mV range up to 40V, and consumes only 2.5A of quiescent P-P n Wide Input Voltage Range: 4.2V to 40V Operating current. A high efficiency switch is included on the die n Adjustable Switching Frequency: 200kHz to 2.2MHz along with the catch diode, boost diode, and the neces- n Integrated Boost and Catch Diodes sary oscillator, control and logic circuitry. Low ripple Burst n 350mA Output Current Mode operation maintains high efficiency at low output n Fixed Output Voltages: 3.3V, 3.42V, 5V currents while keeping the output ripple below 5mV in a 1.8A I at 12V typical application. Current mode topology is used for fast Q IN n Accurate 1V Enable Pin Threshold transient response and good loop stability. A catch diode n Low Shutdown Current: I = 0.7A current limit provides protection against shorted outputs Q n Internal Sense Limits Catch Diode Current and overvoltage conditions. An enable pin with accurate n Power Good Flag threshold is available, producing a low shutdown current n Output Voltage: 1.21V to 25V of 0.7A. A power good flag signals when V reaches OUT n Internal Compensation 90% of the programmed output voltage. The LT3970 is n Small 10-Pin MSOP and (3mm 2mm) DFN Packages available in small 10-pin MSOP and 3mm 2mm DFN packages. L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks a T of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Automotive Battery Regulation n Power for Portable Products n Industrial Supplies Typical a T 5V Step-Down Converter Efficiency 90 1000 V = 12V V IN IN 6V TO 40V 0.22F 80 100 V BOOST IN LT3970 22H V OUT 5V OFF ON EN SW 10 70 350mA PG BD 22pF 1M 1 60 RT FB 22F 2.2F GND 316k 226k 50 0.1 3490 TA01a f = 600kHz 0.01 40 0.01 0.1 1 10 100 LOAD CURRENT (mA) 3970 TA01b 3970fc 1 EFFICIENCY (%) ion pplica ions pplica ion uresLT3970 Series a Te m aximum r a T (Note 1) V , EN Voltage .........................................................40V Operating Junction Temperature Range (Note 2) IN BOOST Pin Voltage ...................................................55V E-, I-grade .......................................... 40C to 125C BOOST Pin Above SW Pin .........................................30V H-grade .............................................. 40C to 150C FB/V , RT Voltage ....................................................6V Storage Temperature Range ................... 65C to 150C OUT PG, BD Voltage .........................................................30V Lead Temperature (Soldering, 10 sec) MS Only ............................................................ 300C p in c F T TOP VIEW TOP VIEW *FB/V 1 10 RT OUT *FB/V 1 10 RT 2 9 OUT EN PG EN 2 9 PG 11 3 V 8 BD IN V 3 8 BD IN GND GND 4 7 BOOST GND 4 7 BOOST GND 5 6 SW GND 5 6 SW MS PACKAGE 10-LEAD PLASTIC MSOP DDB PACKAGE 10-LEAD (3mm 2mm) PLASTIC DFN = 100C/W JA = 76C/W JA EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB *FB for LT3970, V for LT3970-3.3, LT3970-3.42, LT3970-5. OUT o r Der i n F T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3970EDDB PBF LT3970EDDB TRPBF LFCZ 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3970IDDB PBF LT3970IDDB TRPBF LFCZ 10-Lead (3mm 2mm) Plastic DFN 40C to 125C LT3970EMS PBF LT3970EMS TRPBF LTFDB 10-Lead Plastic MSOP 40C to 125C LT3970IMS PBF LT3970IMS TRPBF LTFDB 10-Lead Plastic MSOP 40C to 125C LT3970HMS PBF LT3970HMS TRPBF LTFDB 10-Lead Plastic MSOP 40C to 150C LT3970EDDB-3.3 PBF LT3970EDDB-3.3 TRPBF LFQH 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3970IDDB-3.3 PBF LT3970IDDB-3.3 TRPBF LFQH 10-Lead (3mm 2mm) Plastic DFN 40C to 125C LT3970EMS-3.3 PBF LT3970EMS-3.3 TRPBF LTFQG 10-Lead Plastic MSOP 40C to 125C LT3970IMS-3.3 PBF LT3970IMS-3.3 TRPBF LTFQG 10-Lead Plastic MSOP 40C to 125C LT3970HMS-3.3 PBF LT3970HMS-3.3 TRPBF LTFQG 10-Lead Plastic MSOP 40C to 150C LT3970EDDB-3.42 PBF LT3970EDDB-3.42 TRPBF LGGG 40C to 125C 10-Lead (3mm 2mm) Plastic DFN LT3970EDDB-5 PBF LT3970EDDB-5 TRPBF LFQF 10-Lead (3mm 2mm) Plastic DFN 40C to 125C LT3970IDDB-5 PBF LT3970IDDB-5 TRPBF LFQF 10-Lead (3mm 2mm) Plastic DFN 40C to 125C LT3970EMS-5 PBF LT3970EMS-5 TRPBF LTFQD 10-Lead Plastic MSOP 40C to 125C LT3970IMS-5 PBF LT3970IMS-5 TRPBF LTFQD 10-Lead Plastic MSOP 40C to 125C LT3970HMS-5 PBF LT3970HMS-5 TRPBF LTFQD 10-Lead Plastic MSOP 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: