POWER LOSS (W) LTC3311 5V, 12.5A Synchronous Step-Down Silent Switcher in 3mm x 3mm LQFN FEATURES DESCRIPTION n Pin Compatible with LTC3310/LTC3310S and LTC3311S The LTC 3311 is a very small, low noise, monolithic n Silent Switcher Architecture: step-down DC/DC converter capable of providing up to n Ultralow EMI Emissions 12.5A of output current from a 2.25V to 5.5V input supply. n High Efficiency4.5m NMOS and 16m PMOS The device employs Silent Switcher 1 architecture with n Wide Bandwidth, Fast Transient Response internal hot loop bypass capacitors to achieve both low n Safely Tolerates Inductor Saturation in Overload EMI and high efficiency at switching frequencies as high n V Range: 2.25V to 5.5V as 5MHz. For systems with higher power requirements, IN n V Range: 0.5V to V multi-phasing parallel converters is readily implemented. OUT IN n V Accuracy: 1% with Remote Sense OUT The LTC3311 uses a constant frequency, peak current n Peak Current Mode Control mode control architecture for fast transient response. A n Minimum On-Time: 35ns 500mV reference allows for low voltage outputs. 100% n Programmable Frequency to 5MHz duty cycle operation delivers low drop out. n Precision 400mV Enable Threshold, 1A in Shutdown n Other features include a power good signal when the Output Soft-Start with Voltage Tracking n output is in regulation, precision enable threshold, output Power Good Output n overvoltage protection, thermal shutdown, a temperature Die Temperature Monitor n monitor, clock synchronization, mode selection and Configurable for Paralleling Power Stages in Forced output short circuit protection. The device is available in Continuous Mode n a compact 18-lead 3mm x 3mm LQFN package. Thermally-Enhanced 3mm 3mm LQFN Package n All registered trademarks and trademarks are the property of their respective owners. AEC-Q100 Qualified for Automotive Applications APPLICATIONS n Automotive/Industrial/Communications n Servers, Telecom Power Supplies n Distributed DC Power Systems (POL) n FPGA, ASIC, P Core Supplies TYPICAL APPLICATION Efficiency vs Load Current Efciency vs Load Current 100 4.0 1.2V 12.5A Step-Down Converter f = 2MHz Wurth HCM5030 74435030010 SW 90 3.6 V EFFICIENCY IN 80 3.2 3.0V to 5.5V 22F 22F 2.8 70 V IN EN 100nH V 60 2.4 OUT SW 1.2V MODE/SYNC 50 2.0 12.5A 140k 6.8pF 47F 40 1.6 LTC3311 FB PGOOD 3 V POWER LOSS IN 100k 30 1.2 SSTT 1F 0.1F AGND 20 0.8 V = 3.3V IN ITH V = 1.2V RT OUT PGND 10 0.4 10k f = 2MHz OSC 274k 0 0 470pF 0 1 3 4 5 7 8 9 10 12 13 3311 TA01a (A) 3311 TA01b Rev. 0 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3311 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V ............................................................. 0.3V to 6V IN EN, SSTT ............. 0.3V to Lesser of (V + 0.3V) or 6V IN MODE/SYNC ........ 0.3V to Lesser of (V + 0.3V) or 6V IN 18 17 16 15 RT ........................ 0.3V to Lesser of (V + 0.3V) or 6V EN 1 14 PGOOD IN FB ........................ 0.3V to Lesser of (V + 0.3V) or 6V IN AGND 2 13 MODE/SYNC PGOOD ......................................................... 0.3V to 6V 19 V 3 12 V IN IN PGND I ......................................................................5mA PGOOD V 4 11 V IN IN Operating Junction Temperature Range (Notes 2, 3) PGND 5 10 PGND LTC3311J ......................................... 40C to +150C 6 7 8 9 LTC3311H ........................................ 40C to +150C Storage Temperature............................ 65C to +150C 18-LEAD (3mm 3mm) LQFN PACKAGE Maximum Reflow (Package Body) Temperature ...260C = 42C/W, = 9C/W, = 62C/W, = 14C/W JA JCbottom JCtop JB = 1.25C/W, VALUES DETERMINED PER JESD51-12 JT EXPOSED PAD (PIN 19) IS PGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE TRAY/REEL AUTOMOTIVE PRODUCTS** PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3311JV PBF LTC3311JV WPBF LTC3311HV PBF LTC3311HV WPBF LTC3311JV TRPBF LTC3311JV WTRPBF 18-Lead (3mm 3mm) LQFN LHMN 40C to 150C (Laminate Package with QFN Footprint) LTC3311HV TRPBF LTC3311HV WTRPBF LTC3311JV TRMPBF LTC3311JV WTRMPBF LTC3311HV TRMPBF LTC3311HV WTRMPBF 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. 0 2 For more information www.analog.com SW FB SW ITH SW SSTT SW RT