LTC3805EDD#PBF Analog Devices

POWER LOSS (W) LTC3805 Adjustable Frequency Current Mode Flyback DC/DC Controller Features Description n V and V Limited Only by External Components The LTC 3805 is a current mode controller for flyback IN OUT n Adjustable Slope Compensation DC/DC converters designed to drive an N-channel MOSFET n Adjustable Overcurrent Protection with Automatic in high input and output voltage converter applications. Restart Operating frequency and slope compensation can be n Adjustable Operating Frequency (70kHz to 700kHz) programmed by external resistors. Programmable overcur- with One External Resistor rent sensing protects the converter from short-circuits. n Synchronizable to an External Clock Soft-start can be programmed using an external capacitor n 1.5% Reference Accuracy and the soft-start capacitor also programs an automatic n Current Mode Operation for Excellent Line and Load restart feature. Transient Response The LTC3805 provides 1.5% output voltage accuracy n RUN Pin with Precision Threshold and Adjustable and consumes only 360A of quiescent current during Hysteresis normal operation and only 40A during micropower start- n Programmable Soft-Start with One External Capacitor up. Using a 9.5V internal shunt regulator, the LTC3805 n Low Quiescent Current: 360A can be powered from a high V through a resistor or it IN n Small 10-Lead MSOP and 3mm 3mm DFN can be powered directly from a low impedance DC voltage of 9V or less. a The LTC3805 is available in the 10-lead MSOP package n and the 3mm 3mm DFN package. Telecom Power Supplies n 42V and 12V Automotive Power Supplies L,LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks, No R and ThinSOT are trademarks of Linear Technology Corporation. SENSE n Isolated Electronic Equipment All other trademarks are the property of their respective owners. t a 36V 72V to 5V/2A Nonisolated Flyback Converter Efficiency and Power Loss vs Load Current V = 5V O V OUT V IN 5V 100 10 36V TO V = 48V AT 2A IN 72V 2.2F 90 221k 100k 100F 2 80 2 70 EFFICIENCY 22F 60 50 1 8.66k LOSS V CC 40 RUN GATE 30 LTC3805 1.33k OC 20 I TH 3k 71.5k I SSFLT SENSE 10 20k 0.1F FS FB 0 0.1 0.01 0.1 1 10 SYNC GND 470pF 118k 68m 13.7k LOAD CURRENT (A) 3805 TA01b 3805 TA01a 3805fg 1 EFFICIENCY (%) pplication ypical pplicationsLTC3805 a Maxi Mu M r (Note 1) V to GND OC, I .................................................... 0.3V to 1V CC SENSE Low Impedance Source ........................ 0.3V to 8.8V Operating Junction Temperature Range Current Fed ........................................25mA into V * (Notes 2, 3) ............................................ 55C to 150C CC SYNC ........................................................... 0.3V to 6V Storage Temperature Range .................. 65C to 150C SSFLT........................................................... 0.3V to 5V Lead Temperature (Soldering, 10 sec) FB, I , FS ................................................. 0.3V to 3.5V MSE Package ....................................................300C TH RUN ........................................................... 0.3V to 18V *LTC3805 internal clamp circuit regulates V voltage to 9.5V CC F TOP VIEW TOP VIEW SSFLT 1 10 GATE SSFLT 1 10 GATE I 2 9 V TH CC I 2 9 V TH CC 11 FB 3 11 8 OC FB 3 8 OC RUN 4 7 I SENSE RUN 4 7 I SENSE FS 5 6 SYNC FS 5 6 SYNC MSE PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE T = 150C, = 45C/W JMAX JA 10-LEAD (3mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 11) IS GND, MUST BE CONNECTED TO GND T = 125C, = 45C/W JMAX JA EXPOSED PAD (PIN 11) IS GND, MUST BE CONNECTED TO GND D F M LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3805EDD PBF LTC3805EDD TRPBF LCJM 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3805IDD PBF LTC3805IDD TRPBF LCJM 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3805EMSE PBF LTC3805EMSE TRPBF LTCJK 10-Lead Plastic MSOP 40C to 85C LTC3805IMSE PBF LTC3805IMSE TRPBF LTCJK 10-Lead Plastic MSOP 40C to 125C LTC3805HMSE PBF LTC3805HMSE TRPBF LTCJK 10-Lead Plastic MSOP 40C to 150C LTC3805MPMSE PBF LTC3805MPMSE TRPBF LTCJK 10-Lead Plastic MSOP 55C to 150C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3805EDD LTC3805EDD TR LCJM 10-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3805IDD LTC3805IDD TR LCJM 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3805EMSE LTC3805EMSE TR LTCJK 10-Lead Plastic MSOP 40C to 85C LTC3805IMSE LTC3805IMSE TR LTCJK 10-Lead Plastic MSOP 40C to 125C LTC3805HMSE LTC3805HMSE TR LTCJK 10-Lead Plastic MSOP 40C to 150C LTC3805MPMSE LTC3805MPMSE TR LTCJK 10-Lead Plastic MSOP 55C 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. For more information on lead free part marking, go to: