LT8608/LT8608B 42V, 1.5A Synchronous Step-Down Regulator with 2.5A Quiescent Current FEATURES DESCRIPTION n Wide Input Voltage Range: 3.0V to 42V The LT 8608 is a compact, high efficiency, high speed syn- n Ultralow Quiescent Current Burst Mode Operation chronous monolithic step-down switching regulator that n <2.5A I Regulating 12V to 3.3V consumes only 1.7A of quiescent current. The LT8608 Q IN OUT n Output Ripple <10mV can deliver 1.5A of continuous current. Low ripple Burst P-P n High Efficiency 2MHz Synchronous Operation Mode operation enables high efficiency down to very low n >92% Efficiency at 0.5A, 5V from 12V output currents while keeping the output ripple below OUT IN n 1.5A Continuous Output Current 10mV. Internal compensation with peak current mode n Fast Minimum Switch-On Time: 35ns topology allows the use of small inductors and results in n Adjustable and Synchronizable: 200kHz to 2.2MHz fast transient response and good loop stability. The EN/ n Spread Spectrum Frequency Modulation for Low EMI UV pin has an accurate 1V threshold and can be used to n Allows Use of Small Inductors program V undervoltage lockout or to shut down the IN n Low Dropout LT8608. The PG flag signals when V is within 8.5% of OUT n Peak Current Mode Operation the programmed output voltage as well as fault conditions. n Accurate 1V Enable Pin Threshold The MSOP package includes a SYNC pin to synchronize n Internal Compensation to an external clock, or to select Burst Mode operation n Output Soft-Start and Tracking orpulse-skipping with or without spread-spectrum the n Small 10-Lead MSOP Package or 8-Lead TR/SS pin programs soft-start or tracking. The DFN 2mm2mm DFN Package package omits these pins and can be purchased in pulse- n AEC-Q100 Qualified for Automotive Applications skipping or Burst Mode operation varieties. PACKAGE SYNC FUNCTIONALITY APPLICATIONS LT8608MSE MSE Programmable LT8608DFN DFN Burst Mode Operation n General Purpose Step Down n LT8608BDFN DFN Pulse-Skipping Mode Low EMI Step Down All registered trademarks and trademarks are the property of their respective owners. 12V to 5V Efficiency TYPICAL APPLICATION IN OUT IN OUT 100 5V, 2MHz Step-Down 95 90 V IN V BST 85 IN 5.5V TO 42V 4.7F ON OFF 0.1F EN/UV 2.2H V 80 OUT SYNC SW 5V 75 1.5A 10pF LT8608 70 INTV CC 65 TR/SS PG 1M 60 RT FB 55 1F 18.2k 187k 22F f = 2MHz SW GND 50 8608 TA01a 0 0.25 0.50 0.75 1.00 1.25 1.50 I (A) OUT 8608 TA01b Rev. E 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8608/LT8608B ABSOLUTE MAXIMUM RATINGS (Note 1) Operating Junction Temperature Range (Note 2) V , EN/UV, PG ..........................................................42V IN LT8608E ........................................... 40C to 125C FB, TR/SS ................................................................4V LT8608I ............................................. 40C to 125C SYNC Voltage ...........................................................6V LT8608H ............................................ 40C to 150C Storage Temperature Range .................. 65C to 150C PIN CONFIGURATION TOP VIEW TOP VIEW BST 1 10 EN/UV BST 1 8 EN/UV SW 2 9 V IN 11 INTV 3 8 PG SW 2 7 V CC IN GND 9 RT 4 7 TR/SS GND INTV 3 6 PG CC SYNC 5 6 FB RT 4 5 FB MSE PACKAGE 10-LEAD PLASTIC MSOP = 40C/W, = 10C/W DC PACKAGE JA JC EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB 8-LEAD (2mm 2mm) PLASTIC DFN ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT8608EMSE PBF LT8608EMSE TRPBF LTGVZ 10-Lead Plastic MSOP 40C to 125C LT8608IMSE PBF LT8608IMSE TRPBF LTGVZ 10-Lead Plastic MSOP 40C to 125C LT8608HMSE PBF LT8608HMSE TRPBF LTGVZ 10-Lead Plastic MSOP 40C to 150C LT8608EDC TRMPBF LT8608EDC TRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 40C to 125C LT8608IDC TRMPBF LT8608IDC TRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 40C to 125C LT8608HDC TRMPBF LT8608HDC TRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 40C to 150C LT8608BEDC TRMPBF LT8608BEDC TRPBF LGXC 8-Lead (2mm 2mm) Plastic DFN 40C to 125C LT8608BIDC TRMPBF LT8608BIDC TRPBF LGXC 8-Lead (2mm 2mm) Plastic DFN 40C to 125C LT8608BHDC TRMPBF LT8608BHDC TRPBF LGXC 8-Lead (2mm 2mm) Plastic DFN 40C to 150C AUTOMOTIVE PRODUCTS** LT8608EMSE WPBF LT8608EMSE WTRPBF LTGVZ 10-Lead Plastic MSOP 40C to 125C LT8608IMSE WPBF LT8608IMSE WTRPBF LTGVZ 10-Lead Plastic MSOP 40C to 125C LT8608JMSE WPBF LT8608JMSE WTRPBF LTGVZ 10-Lead Plastic MSOP 40C to 150C LT8608HMSE WPBF LT8608HMSE WTRPBF LTGVZ 10-Lead Plastic MSOP 40C to 150C LT8608EDC WTRMPBF LT8608EDC WTRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 40C to 125C LT8608IDC WTRMPBF LT8608IDC WTRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 40C to 125C LT8608JDC WTRMPBF LT8608JDC WTRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 40C to 150C LT8608HDC WTRMPBF LT8608HDC WTRPBF LGXB 8-Lead (2mm 2mm) Plastic DFN 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. Rev. E 2 For more information www.analog.com