POWER LOSS (W) LTC7151S 20V, 15A Synchronous Step-Down Silent Switcher 2 Regulator FEATURES DESCRIPTION n Silent Switcher 2 Architecture for Low EMI The LTC 7151S is a high efficiency monolithic synchro- n V Range: 3.1V to 20V nous buck regulator capable of delivering 15A to the load. IN n V Range: 0.5V to 5.5V It uses a phase lockable controlled on-time constant fre- OUT n Differential V Remote Sense quency, current mode architecture. PolyPhase operation OUT n Adjustable Frequency: 400kHz to 3MHz allows multiple LTC7151S regulators to run out-of-phase, n PolyPhase Operation: Up to 12 Phases which reduces the amount of input and output capacitors n Output Tracking and Soft-Start required. The operating supply voltage range is from 3.1V n Reference Accuracy: 1% Overtemperature to 20V. n Current Mode Operation for Excellent Line and Load The operating frequency is programmable from 400kHz Transient Response to 3MHz with an external resistor. The high frequency n Accurate 1.2V Run Pin Threshold capability allows the use of physically smaller inductor n Supports Forced Continuous/Discontinuous Modes and capacitor sizes. For switching noise sensitive applica- n 28-Lead Thermally Enhanced 4mm 5mm tions, the LTC7151S can be externally synchronized from 0.74mm LQFNPackage 400kHz to 3MHz. The PHMODE pin allows the user control of the phase of the outgoing clock signal. The unique con- APPLICATIONS stant frequency/controlled on-time architecture is ideal for high step-down ratio applications that operate at high n Automotive and Industrial Power Supplies frequencies while demanding fast transient response. The n Server Power Applications LTC7151S uses second generation Silent Switcher 2 tech- n Distributed Power Systems nology including integrated bypass capacitors to deliver a n Point-of-Load Supply for ASIC, FPGA, DSP, P, etc. highly efficient solution at high frequencies with excellent All registered trademarks and trademarks are the property of their respective owners. EMI performance. TYPICAL APPLICATION 12V to 1.0V Application Efficiency and Power Loss IN OUT Efciency and Power Loss 0.25H 100 6 V V SV = 5V, PV = 12V IN IN IN OUT RUN SW 3.1V TO 20V 1.0V/15A f = 1MHz SW 10k 22F 95 5 PV + IN FB 2 100F 330F 2 SV LTC7151S IN 10k 90 4 PHMODE V OUT 85 3 TRACK/SS PGOOD CLKOUT MODE/SYNC 80 2 INTV GND CC RT ITH 4.7F 75 1 7151S TA01a 70 0 162k 22pF 10k 0 3 6 9 12 15 I (A) 1nF OUT 7151S TA01b Rev. 0 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC7151S ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW PV , SV ................................................. 0.3V to 22V IN IN RUN Voltage............................................. 0.3V to SV IN MODE/SYNC, TRACK/SS Voltage .........0.3V to INTV 28 27 26 25 24 23 CC CLKOUT 1 22 V OUT ITH, RT, PGOOD Voltage ........................... 0.3V to 3.6V RUN 2 21 MODE/SYNC PHMODE, CLK Voltage .............................. 0.3V to 3.6V 29 30 SV 3 GND GND 20 INTV IN CC V Voltage ........................................... 0.3V to 0.3V OUT PV 4 19 PV IN IN FB Voltage ................................................. 0.3V to 3.6V PV 5 18 PV IN IN Operating Junction Temperature Range ................ 125C GND 6 31 32 17 GND GND GND Storage Temperature Range .................. 65C to 150C GND 7 16 GND GND 8 15 GND Maximum Internal Temperature ............................ 125C 9 10 11 12 13 14 Peak Reflow Solder Body Temperature .................260C LQFN PACKAGE 28-LEAD (5mm 4mm 0.74mm) = 31C/W, = 6C/W, = 16C/W JA JC(PAD) JC(TOP) EXPOSED PADS (PINS 29-32) ARE GND, SHOULD BE SOLDERED TO PCB ORDER INFORMATION PART MARKING* PACKAGE MSL TEMPERATURE RANGE PART NUMBER TAPE AND REEL PAD FINISH DEVICE FINISH CODE TYPE** RATING (SEE NOTE 2) LTC7151SEV PBF LTC7151SEV TRPBF 7151S Au (RoHS) e4 LQFN 3 40C to 125C LTC7151SIV PBF LTC7151SIV TRPBF 7151S Contact the factory for parts specified with wider operating temperature ranges.*Pad finish code is per IPC/JEDEC J-STD-609. *Temperature grades are identified by a label on the shipping container. Parts ending with PBF are RoHS and WEEE compliant. **The LTC7151S package has the same dimensions as a standard 5mm 4mm 0.75mm QFN package. ELECTRICAL CHARACTERISTICSThe l denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at T = 25C (Note 2). V = 12V, unless otherwise noted. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS l SV SV Operating Voltage 3.1 20 V IN IN PV PV Operating Voltage 20 V IN IN V V Operation Voltage 0.5 5.5 V OUT OUT I Input Quiescent Current (Note 3) Active Mode 2 4 mA Q Shutdown Mode V = 0V 20 40 A RUN V Feedback Reference Voltage (Note 4) ITH = 1.0V 0.499 0.500 0.501 V FB l ITH = 1.0V, 40C to 125C 0.495 0.500 0.505 V V Feedback Voltage Line and Load Regulation (Note 4) l 0.2 0.5 % FB(LINE+LOAD) I Feedback Pin Input Current 50 50 nA FB g (EA) Error Amplifier Transconductance ITH = 1.0V 1.0 1.3 1.6 mS m l t Minimum On-Time 20 25 ns ON(MIN) t Minimum Off-Time 50 ns OFF(MIN) Rev. 0 2 For more information www.analog.com SW PHMODE SW RT SW PGOOD SW TRACK/SS SW ITH SW FB