LT8650S Dual Channel 4A, 42V, Synchronous Step-Down Silent Switcher 2 with 6.2A Quiescent Current FEATURES DESCRIPTION n Silent Switcher 2 Architecture: The LT 8650S is a dual step-down regulator that delivers n Ultralow EMI on Any PCB up to 4A of continuous current from both channels and n Eliminates PCB Layout Sensitivity supports loads up to 6A from each channel. The LT8650S n Internal Bypass Capacitors Reduce Radiated EMI features the second generation Silent Switcher architecture n Optional Spread Spectrum Modulation to minimize EMI emissions while delivering high efficiency n 4A DC from Each Channel Simultaneously at high switching frequencies. This includes integration of n Up to 6A on Either Channel bypass capacitors to optimize high frequency current loops n Ultralow Quiescent Current Burst Mode Operation: and make it easy to achieve advertised EMI performance n 6.2A I Regulating 12V to 5V and 3.3V by eliminating layout sensitivity. Q IN OUT1 OUT2 n Output Ripple <10mV P-P The fast, clean, low overshoot, switching edges enable n Optional External VC Pin: Fast Transient Response high efficiency operation even at high switching frequen- and Current Sharing (Extra 50A I /Channel) Q cies, leading to a small overall solution size. Peak current n Forced Continuous Mode mode control with a 40ns minimum on-time allows high n High Efficiency at High Frequency step down ratios at high switching frequencies. n 94.6% Efficiency at 2A, 5V from 12V at 2MHz OUT IN n Burst Mode operation features a 6.2A quiescent current 93.3% Efficiency at 4A, 5V from 12V at 2MHz OUT IN n resulting in high efficiency at low output currents, forced Fast Minimum Switch On-Time: 40ns n continuous mode allows fixed switching frequency opera- Wide Input Voltage Range: 3.0V to 42V n tion over the entire output load range, and spread spectrum Adjustable and Synchronizable: 300kHz to 3MHz n operation can further reduce EMI emissions. External VC Small 4mm 6mm 32-Pin LQFN Package n pins allow optimal loop compensation for fast transient AEC-Q100 Qualified for Automotive Applications response. The VC pins can also be used for current sharing and the CLKOUT pin enables synchronizing two LT8650S APPLICATIONS chips to generate a 4-phase, 16A supply. n General Purpose Step-Down All registered trademarks and trademarks are the property of their respective owners. Protected n Automotive and Industrial Supplies by U.S patents, including 8823345. TYPICAL APPLICATION 5V/4A, 3.3V/4A 2MHz Step-Down Converter Efficiency 100 V V IN1 IN2 V V IN1 IN2 5.4V TO 42V 3.7V TO 42V 95 4.7F 4.7F EN/UV1 EN/UV2 90 1.0H 1.0H V V OUT1 OUT2 85 5V SW1 SW2 3.3V 4A 4A 47F 47F 80 4.7pF 1M 1M 4.7pF 2 2 75 FB1 FB2 70 LT8650S 191k 316k V VC1 VC2 V CC CC 65 SS1 SS2 60 10nF 10nF 55 50 BIAS V = V = 12V CH1 5V IN1 IN2 45 f = 2MHz RT V GND SYNC SW CH2 3.3V CC 40 0 1 2 3 4 5 6 15k 1F LOAD CURRENT (A) 8650S TA01a 8650s TA01b f = 2MHz SW Rev. C 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8650S ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , V , EN/UV1, EN/UV2, PG1, PG2 .....................42V IN1 IN2 BIAS ..........................................................................30V 32 31 30 29 28 27 FB1, FB2, SS1, SS2 ..................................................4V RT 1 26 BIAS VC1, VC2 ..................................................................3.5V GND 2 25 V SYNC........................................................................6V CC 33 34 GND GND Operating Junction Temperature Range (Note 2) 24 BST1 LT8650SE .............................................. 40 to 125C V 4 23 SW1 IN1 LT8650SI ............................................... 40 to 125C V 5 22 SW1 IN1 35 36 LT8650SJ ..............................................40 to 150C GND GND LT8650SH ..............................................40 to 150C V 7 20 SW2 IN2 Storage Temperature Range ......................65 to 150C V 8 19 SW2 IN2 37 38 Maximum Reflow (Package Body) GND GND 18 BST2 Temperature ......................................................260C GND 10 17 CLKOUT 11 12 13 14 15 16 LQFN PACKAGE 32-LEAD (6mm 4mm 0.94mm) T = 125C, = 23C/W JMAX JA EXPOSED PAD (PINS 33, 34, 35, 36, 37, 38) ARE GND, MUST BE SOLDERED TO PCB ORDER INFORMATION PART MARKING PAD OR BALL PACKAGE* MSL TEMPERATURE RANGE LEAD FREE FINISH TAPE AND REEL FINISH DEVICE FINISH CODE TYPE RATING (SEE NOTE 2) LT8650SEV PBF LT8650SEV TRPBF 40C to 125C LQFN (Laminate Package LT8650SIV PBF LT8650SIV TRPBF Au (RoHS) 8650SV e4 3 40C to 125C with QFN Footprint) LT8650SHV PBF LT8650SHV TRPBF 40C to 150C AUTOMOTIVE PRODUCTS** LT8650SEV WPBF LT8650SEV WTRPBF 40C to 125C LT8650SIV WPBF LT8650SIV WTRPBF 40C to 125C LQFN (Laminate Package Au (RoHS) 8650SV e4 3 with QFN Footprint) LT8650SJV WPBF LT8650SJV WTRPBF 40C to 150C LT8650SHV WPBF LT8650SHV WTRPBF 40C to 150C Device temperature grade is indicated by a label on the shipping container. Recommended PCB Assembly and Manufacturing Procedures. Pad or ball finish code is per IPC/JEDEC J-STD-609. Package and Tray Drawings *The LT8650S package has the same dimensions as a standard 6mm4mm 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. C 2 For more information www.analog.com EN1 VC2 EN2 FB2 TEMP SS2 PG1 SS1 PG2 FB1 SYNC VC1