LT8609S 42V, 2A/3A Peak Synchronous Step-Down Regulator with 2.5A Quiescent Current FEATURES DESCRIPTION n Silent Switcher 2 Architecture The LT 8609S is a compact, high efficiency, high speed n Ultralow EMI Emissions on Any PCB synchronous monolithic step-down switching regulator n Eliminates PCB Layout Sensitivity that consumes only 1.7A of non-switching quiescent n Internal Bypass Capacitors Reduce Radiated EMI current. The LT8609S can deliver 2A of continuous cur- n Optional Spread Spectrum Modulation rent with peak loads of 3A (<1sec) to support applications n Wide Input Voltage Range: 3.0V to 42V such as GSM transceivers which require high transient n Ultralow Quiescent Current Burst Mode Operation: loads. Top and bottom power switches are included with n <2.5A I Regulating 12V to 3.3V all necessary circuitry to minimize the need for external Q IN OUT n Output Ripple <10mV components. Low ripple Burst Mode operation enables P-P n High Efficiency 2MHz Synchronous Operation: high efficiency down to very low output currents while n >93% Efficiency at 1A, 12V to 5V keeping the output ripple below 10mV . A SYNC pin IN OUT P-P n 2A Maximum Continuous Output, 3A Peak Transient allows synchronization to an external clock, or spread Output spectrum modulation of switching frequencies for low n Fast Minimum Switch-On Time: 45ns EMI operation. Internal compensation with peak current n Adjustable and Synchronizable: 200kHz to 2.2MHz mode topology allows the use of small inductors and n Allows Use of Small Inductors results in fast transient response and good loop stability. n Low Dropout The EN/UV pin has an accurate 1V threshold and can be n Peak Current Mode Operation used to program V undervoltage lockout or to shut down IN n Internal Compensation the LT8609S reducing the input supply current to 1A. A n Output Soft-Start and Tracking capacitor on the TR/SS pin programs the output voltage n Small 16-Lead 3mm 3mm LQFN Package ramp rate during start-up while the PG flag signals when n AEC-Q100 Qualified for Automotive Applications V is within 8.5% of the programmed output voltage OUT as well as fault conditions. The LT8609S is available in a APPLICATIONS small 16-lead 3mm 3mm LQFN package. All registered trademarks and trademarks are the property of their respective owners. n General Purpose Step Down n Low EMI Step Down 12V to 5V Efficiency TYPICAL APPLICATION IN OUT 100 5V, 2MHz Step Down 95 90 V IN V IN 5.5V TO 40V 85 4.7F ON OFF EN/UV 2.2H V OUT 80 SYNC SW 5V 10pF 2A LT8609S 75 INTV CC 70 TR/SS PG 1M 65 RT FB 1F 18.2k 182k 22F 60 GND 55 8609S TA01a f = 2MHz SW 50 0 0.50 1.00 1.50 2.00 2.50 I (A) OUT 8609S TA01b Rev. D 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8609S ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , EN/UV, PG ..........................................................42V IN FB, TR/SS ................................................................4V N/C N/C SYNC Voltage ...........................................................6V 16 15 14 13 Operating Junction Temperature Range (Note 2) RT 1 12 PG LT8609SE .............................................. 40 to 125C V 2 11 EN/UV CC 17 LT8609SI ............................................... 40 to 125C GND GND 3 10 V IN Storage Temperature Range ......................65 to 150C GND 4 9 V Maximum Reflow (Package Body) IN Temperature ......................................................260C 5 6 7 8 N/C N/C LQFN PACKAGE 16-LEAD (3mm 3mm) LQFN JEDEC BOARD: = 50C/W, = 14C/W (NOTE 4) JA JC(PAD) DEMOBOARD: = 31C/W JA EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION PART FINISH PAD PACKAGE MSL PART NUMBER TAPE AND REEL MARKING* CODE FINISH TYPE** RATING TEMPERATURE RANGE LT8609SEV PBF LT8609SEV TRPBF LGYN 40C to 125C Au LQFN (Laminate Package e4 3 with QFN Footprint (RoHS) LT8609SIV PBF LT8609SIV TRPBF LGYN 40C to 125C AUTOMOTIVE PRODUCTS** LT8609SEV WPBF LT8609SEV WTRPBF LGYN 40C to 125C Au LQFN (Laminate Package e4 3 (RoHS) with QFN Footprint LT8609SIV WPBF LT8609SIV WTRPBF LGYN 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. Pad or ball finish code is per IPC/JEDEC J-STD-609. Recommended PCB Assembly and Manufacturing Procedures. Package and Tray Drawings Parts ending with PBF are RoHS and WEEE compliant. ** The LT8609S package has the same footprint as a standard 3mm 3mm QFN Package. **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. D 2 For more information www.analog.com SW SYNC SW TR/SS N/C GND GND FB