LTC3873EDDB#TRMPBF Analog Devices

POWER LOSS (mW) LTC3873 TM No R Constant Frequency SENSE Current Mode Boost/Flyback/SEPIC DC/DC Controller FEATURES DESCRIPTION n V and V Limited Only by External Components The LTC 3873 is a constant frequency current mode, IN OUT n Internal or Programmable External Soft-Start boost, flyback or SEPIC DC/DC controller that drives an n Constant Frequency 200kHz Operation N-channel power MOSFET in high input and output voltage n Adjustable Current Limit converter applications. Soft-start can be programmed n Current Sense Resistor Optional using an external capacitor. n Maximum 60V on SW Node with R Sensing DS(ON) The LTC3873 provides 1.5% output voltage accuracy and n 1.5% Voltage Reference Accuracy consumes only 300A quiescent current during normal n Current Mode Operation for Excellent Line and Load operation and only 55A during micropower start-up. Transient Response Using a 9.3V internal shunt regulator, the LTC3873 can n Low Quiescent Current: 300A be powered from a high input voltage through a resistor TM n Low Profile (1mm) ThinSOT and (0.75mm) or it can be powered directly from a low impedance DC 2mm 3mm DFN Package voltage of 9V or less. The LTC3873 is available in 8-lead ThinSOT and 2mm APPLICATIONS 3mm DFN packages. PARAMETER LTC3873 LTC3873-5 n Telecom Power Supplies + V UV 8.4V 4.1V n CC 42V and 12V Automotive Power Supplies V UV 4V 2.9V CC n Portable Electronic Equipment All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION 5V Output Nonisolated Telecom Power Supply Efficiency and Power Loss vs Load Current V IN 36V TO 72V 100 3000 D2 V OUT 90 T1 5V EFFICIENCY 4.7F 100F 2A MAX 2500 80 221k 100V D1 6.3V X5R X5R 70 2000 3 10F 60 10V 50 1500 X5R V CC POWER LOSS M1 40 I NGATE TH 1000 LTC3873 7.5k 30 V = 72V RUN/SS IN 20 V = 60V 2.2nF 0.1F IN 500 GND SW V = 48V IN 10 IPRG V = 36V 68m IN 0 10 V FB 10 1000 12.1k 38.3k LOAD CURRENT (mA) 3873 TA01a 3873 TA01b Rev. C 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3873 ABSOLUTE MAXIMUM RATINGS (Note 1) V to GND SW Voltage ................................................ 0.3V to 60V CC Low Impedance Source ........................... 0.3V to 9V Operating Temperature Range (Note 2).... 40C to 85C Current Fed ..........................................25mA Into V Junction Temperature (Note 3) ............................. 125C CC RUN/SS ........................................................ 0.3V to 9V Storage Temperature Range ................... 65C to 125C IPRG Voltage .................................0.3V to (V + 0.3V) Lead Temperature (Soldering, 10 sec) CC V , I Voltages ....................................... 0.3V to 2.4V TS8 Package ..................................................... 300C FB TH PIN CONFIGURATION TOP VIEW TOP VIEW GND 1 8 NGATE IPRG 1 8 SW V 2 7 V FB CC I 2 7 RUN/SS TH 9 I 3 6 RUN/SS TH V 3 6 V FB CC IPRG SW GND 4 5 NGATE 4 5 TS8 PACKAGE 8-LEAD PLASTIC TSOT-23 DDB PACKAGE 8-LEAD (3mm 2mm) PLASTIC DFN T = 125C, = 230C/W JMAX JA T = 125C, = 76C/W JMAX JA EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3873ETS8 PBF LTC3873ETS8 TRPBF LTCSN 8-Lead Plastic TSOT-23 40C to 85C LTC3873EDDB PBF LTC3873EDDB TRPBF LCSK 8-Lead (3mm 2mm) Plastic DFN 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3873ETS8 LTC3873ETS8 TR LTCSN 8-Lead Plastic TSOT-23 40C to 85C LTC3873EDDB LTC3873EDDB TR LCSK 8-Lead (3mm 2mm) Plastic DFN 40C to 85C 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. Rev. C 2 For more information www.analog.com