POWER LOSS (W) LTC3872 No R SENSE Current Mode Boost DC/DC Controller Fea T Descrip T n No Current Sense Resistor Required The LTC 3872 is a constant frequency current mode n V up to 60V boost DC/DC controller that drives an N-channel power OUT n Constant Frequency 550kHz Operation MOSFET and requires very few external components. The TM n Internal Soft-Start and Optional External Soft-Start No R architecture eliminates the need for a sense SENSE n Adjustable Current Limit resistor, improves efficiency and saves board space. n Pulse Skipping at Light Load The LTC3872 provides excellent AC and DC load and line n V Range: 2.75V to 9.8V IN regulation with 1.5% output voltage accuracy. It incor- n 1.5% Voltage Reference Accuracy porates an undervoltage lockout feature that shuts down n Current Mode Operation for Excellent Line and Load the device when the input voltage falls below 2.3V. Transient Response n High switching frequency of 550kHz allows the use of a Low Profile (1mm) SOT-23 and 2mm 3mm DFN small inductor. The LTC3872 is available in an 8-lead low Packages TM profile (1mm) ThinSOT package and 8-pin 2mm 3mm DFN package. a T L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No R and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks SENSE n Telecom Power Supplies are the property of their respective owners. n 42V Automotive Systems n 24V Industrial Controls n IP Phone Power Supplies Typical a T High Efficiency 3.3V Input, 5V Output Boost Converter Efficiency and Power Loss vs Load Current 100 10 1.8nF 17.4k 90 V IN I V TH IN 3.3V 80 47pF V 10F IN IPRG 1 1H 70 LTC3872 D1 60 GND SW 50 0.1 M1 V RUN/SS NGATE FB 40 11k V 1% OUT 1nF 30 5V 34.8k 0.01 2A 100F 20 1% 2 10 3872 TA01 0 0.001 1 10 100 1000 10000 LOAD CURRENT (mA) 3872 TA01b 3872fc For more information www.linear.com/LTC3872 1 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3872 a Te Maxi Mu M r a T (Note 1) Input Supply Voltage (V ), RUN/SS .......... 0.3V to 10V Operating Junction Temperature Range IN IPRG Voltage ................................. 0.3V to (V + 0.3V) (Notes 2, 3) ............................................ 40C to 150C IN V , I Voltages ....................................... 0.3V to 2.4V Storage Temperature Range .................. 65C to 150C FB TH SW Voltage ................................................ 0.3V to 60V Lead Temperature (Soldering, 10 sec) TS8 Package .........................................................300C p in c F T TOP VIEW TOP VIEW GND 1 8 NGATE IPRG 1 8 SW V 2 7 V FB IN I 2 7 RUN/SS TH 9 I 3 6 RUN/SS TH V 3 6 V FB IN IPRG 4 5 SW GND 4 5 NGATE TS8 PACKAGE 8-LEAD PLASTIC TSOT-23 DDB PACKAGE 8-LEAD (3mm 2mm) PLASTIC DFN T = 150C, = 195C/W JMAX JA T = 150C, = 76C/W JMAX JA EXPOSED PAD (PIN 9) IS GND MUST BE SOLDERED TO PCB o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3872ETS8 PBF LTC3872ETS8 TRPBF LCGB 8-Lead Plastic TSOT-23 40C to 85C LTC3872ITS8 PBF LTC3872ITS8 TRPBF LCGB 8-Lead Plastic TSOT-23 40C to 125C LTC3872HTS8 PBF LTC3872HTS8 TRPBF LCGB 8-Lead Plastic TSOT-23 40C to 150C LTC3872EDDB PBF LTC3872EDDB TRPBF LCHT 8-Lead (3mm 2mm) Plastic DFN 40C to 85C LTC3872IDDB PBF LTC3872IDDB TRPBF LCHT 8-Lead (3mm 2mm) Plastic DFN 40C to 125C LTC3872HDDB PBF LTC3872HDDB TRPBF LCHT 8-Lead (3mm 2mm) Plastic DFN 40C to 150C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: