POWER LOSS (W) LTC3605 15V, 5A Synchronous Step-Down Regulator FEATURES DESCRIPTION n High Efficiency: Up to 96% The LTC 3605 is a high efficiency, monolithic synchronous n 5A Output Current buck regulator using a phase lockable controlled on-time n 4V to 15V V Range constant frequency, current mode architecture. PolyPhase IN n Integrated Power N-Channel MOSFETs operation allows multiple LTC3605 regulators to run out of (70m Top and 35m Bottom) phase while using minimal input and output capacitance. n Adjustable Frequency 800kHz to 4MHz The operating supply voltage range is from 15V down to n PolyPhase Operation (Up to 12 Phases) 4V, making it suitable for dual lithium-ion battery inputs n Output Tracking as well as point of load power supply applications from n 0.6V 1% Reference Accuracy a 12V or 5V rail. n Current Mode Operation for Excellent Line and Load The operating frequency is programmable from 800kHz to Transient Response 4MHz with an external resistor. The high frequency capa- n Shutdown Mode Draws Less Than 15A Supply Current bility allows the use of small surface mount inductors. For n Available in 24-Pin (4mm 4mm) QFN Package switching noise sensitive applications, it can be externally n AEC-Q100 Qualified for Automotive Applications synchronized from 800kHz to 4MHz. The PHMODE pin allows user control of the phase of the outgoing clock APPLICATIONS signal. The unique constant frequency/controlled on-time architecture is ideal for high step-down ratio applications n Point of Load Power Supply that are operating at high frequency while demanding n Portable Instruments fast transient response. Two internal phase-lock loops n Distributed Power Systems synchronize the internal oscillator to the external clock n Battery-Powered Equipment and also servos the regulator on-time to lock on to either the internal clock or the external clock if its present. All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611. TYPICAL APPLICATION Efficiency and Power Loss High Efficiency 1MHz, 5A Step-Down Regulator 100 10 V = 12V V = 3.3V IN OUT V IN 90 f = 1MHz 4V TO 15V 22F 80 PV SV 2 IN IN 70 CLKOUT INTV CC 1 V = 1.2V OUT 2.2F 60 CLKIN BOOST 50 PGOOD 0.1F 1H LTC3605 V 40 OUT V = 3.3V SW OUT 3.3V V = 1.2V OUT 0 30 V 11.5k ON 47F V RUN FB IN 20 2 ITH 2.55k 10 RT 16k PGND 0 0.1 10 100 1000 10000 162k 220pF OUTPUT CURRENT (mA) 3605 TA01a 3605 TA01b Rev. I 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3605 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW PV , SV , SW Voltage.............................. 0.3V to 15V IN IN SW Transient Voltage ..................................2V to 17.5V BOOST Voltage ..........................0.3V to PV + INTV IN CC 24 23 22 21 20 19 RUN Voltage............................................... 0.3V to 15V RT 1 18 PV IN V Voltage ............................................... 0.3V to SV PHMODE 2 17 PV ON IN IN INTV Voltage ......................................... 0.3V to 3.6V MODE 3 16 SW 25 CC PGND FB 4 15 SW ITH, RT, CLKOUT, PGOOD Voltage ........0.3V to INTV CC TRACK/SS 5 14 SW CLKIN, PHMODE, MODE Voltage ..........0.3V to INTV CC ITH 6 13 SW TRACK/SS, FB Voltage ..........................0.3V to INTV CC 7 8 9 10 11 12 Operating Temperature Range (Note 2).. 40C to 125C Junction Temperature (Note 5) ............................. 125C Storage Temperature Range .................. 65C to 125C UF PACKAGE 24-LEAD (4mm 4mm) PLASTIC QFN T = 125C, = 37C/W JMAX JA EXPOSED PAD (PIN 25) IS PGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3605EUF PBF LTC3605EUF TRPBF 3605 24-Lead (4mm 4mm) Plastic QFN 40C to 85C LTC3605IUF PBF LTC3605IUF TRPBF 3605 24-Lead (4mm 4mm) Plastic QFN 40C to 125C AUTOMOTIVE PRODUCTS** LTC3605EUF WPBF LTC3605EUF WTRPBF 3605 24-Lead (4mm 4mm) Plastic QFN 40C to 85C LTC3605IUF WPBF LTC3605IUF WTRPBF 3605 24-Lead (4mm 4mm) Plastic QFN 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. 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. I 2 For more information www.analog.com RUN CLKIN PGOOD CLKOUT V SGND ON PGND INTV CC SW BOOST SW SV IN