POWER LOSS (mW) LTC3809-1 TM No R , Low Input SENSE Voltage, Synchronous DC/DC Controller with Output Tracking FEATURES DESCRIPTION n Programmable Output Voltage Tracking The LTC 3809-1 is a synchronous step-down switching n No Current Sense Resistor Required regulator controller that drives external complementary n Constant Frequency Current Mode Operation for power MOSFETs using few external components. The Excellent Line and Load Transient Response constant frequency current mode architecture with MOSFET n Wide V Range: 2.75V to 9.8V V sensing eliminates the need for a current sense resistor IN DS n Wide V Range: 0.6V to V and improves ef ciency. OUT IN n 0.6V 1.5% Reference Optional Burst Mode operation provides high ef ciency n Low Dropout Operation: 100% Duty Cycle operation at light loads. 100% duty cycle provides low n Selectable Burst Mode /Pulse-Skipping/Forced dropout operation, extending operating time in battery- Continuous Operation powered systems. Burst Mode is inhibited when the MODE n Auxiliary Winding Regulation pin is pulled low to reduce noise and RF interference. n Internal Soft-Start Circuitry n The LTC3809-1 allows either coincident or ratiometric Selectable Maximum Peak Current Sense Threshold n output voltage tracking. Switching frequency is xed at Output Overvoltage Protection n 550kHz. Fault protection is provided by an overvoltage Micropower Shutdown: I = 9A Q n comparator and a short-circuit current limit comparator. Tiny Thermally Enhanced Leadless (3mm 3mm) DFN and 10-lead MSOP Packages The LTC3809-1 is available in tiny footprint thermally enhanced DFN and 10-lead MSOP packages. APPLICATIONS , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst n is a registered trademark of Linear Technology Corporation. No R is a trademark of 1- or 2-Cell Lithium-Ion Powered Devices SENSE Linear Technology Corporation. All other trademarks are the property of their respective n Notebook and Palmtop Computers, PDAs owners. Protected by U.S. Patents including 5481178, 5929620, 6580258, 6304066, 5847554, 6611131, 6498466. Other Patents pending. n Portable Instruments n Distributed DC Power Systems TYPICAL APPLICATION Ef ciency and Power Loss vs Load Current High Ef ciency, 550kHz Step-Down Converter 100 10k EFFICIENCY V IN 2.75V TO 9.8V V = 3.3V IN 10F 90 1k V IN IPRG V = 4.2V V = 5V IN IN 80 100 MODE TG 59k LTC3809-1 2.2H V OUT TYPICAL POWER V SW 2.5V FB 70 10 LOSS (V = 4.2V) 15k IN 2A I BG TH 47F 187k RUN 470pF 60 1 GND FIGURE 8 CIRCUIT V = 2.5V OUT 38091 TA01 50 0.1 1 10 100 1k 10k LOAD CURRENT (mA) 38091 TA02 38091fc 1 EFFICIENCY (%)LTC3809-1 (Note 1) ABSOLUTE MAXIMUM RATINGS Input Supply Voltage (V ) ........................ 0.3V to 10V Storage Ambient Temperature Range IN RUN, TRACK/SS, MODE, DFN ....................................................65C to 125C IPRG Voltages ............................... 0.3V to (V + 0.3V) MSOP ................................................65C to 150C IN V , I Voltages ...................................... 0.3V to 2.4V Junction Temperature (Note 3) ............................ 125C FB TH SW Voltage ......................... 2V to V + 1V (10V Max) Lead Temperature (Soldering, 10 sec) IN TG, BG Peak Output Current (<10s) ......................... 1A MSOP Package .................................................300C Operating Temperature Range (Note 2)....40C to 85C PIN CONFIGURATION TOP VIEW TOP VIEW MODE 1 10 SW MODE 1 10 SW TRACK/SS 9 V 2 IN TRACK/SS 2 9 V IN V 3 11 8 TG 3 11 V 8 TG FB FB I 4 7 BG TH 4 I 7 BG TH RUN 5 6 IPRG RUN 5 6 IPRG MSE PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE T = 125C, = 40C/W JMAX JA 10-LEAD (3mm 3mm) PLASTIC DFNs EXPOSED PAD (PIN 11) IS GND T = 125C, = 43C/W JMAX JA (MUST BE SOLDERED TO PCB) EXPOSED PAD (PIN 11) IS GND (MUST BE SOLDERED TO PCB) ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3809EDD-1 PBF LTC3809EDD-1 TRPBF LBQZ 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3809IDD-1 PBF LTC3809IDD-1 TRPBF LBQZ 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3809EMSE-1 PBF LTC3809EMSE-1 TRPBF LTBQV 10-Lead Plastic MSOP 40C to 85C LTC3809IMSE-1 PBF LTC3809IMSE-1 TRPBF LTBQV 10-Lead Plastic MSOP 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3809EDD-1 LTC3809EDD-1 TR LBQZ 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3809IDD-1 LTC3809IDD-1 TR LBQZ 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3809EMSE-1 LTC3809EMSE-1 TR LTBQV 10-Lead Plastic MSOP 40C to 85C LTC3809IMSE-1 LTC3809IMSE-1 TR LTBQV 10-Lead Plastic MSOP 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. For more information on lead free part marking, go to: