POWER LOSS (W) LTC3565 1.25A, 4MHz, Synchronous Step-Down DC/DC Converter FEATURES DESCRIPTION n High Efficiency: Up to 95% The LTC 3565 is a constant frequency, synchronous n V Range: 2.5V to 5.5V step-down DC/DC converter. Intended for medium power IN n High Frequency Operation: Up to 4MHz applications, it operates from a 2.5V to 5.5V input voltage n Selectable Low Ripple (Typical 25mV ) range and has a user-configurable operating frequency up p-p Burst Mode Operation: I = 40A to 4MHz, allowing the use of tiny, low cost capacitors and Q n Stable with Ceramic Capacitors inductors 1mm or less in height. The output voltage is n Uses Tiny Capacitors and Inductor adjustable from 0.6V to 5.5V. Internal synchronous power n Low R Internal Switches: 0.15 switches provide high efficiency. The LTC3565s current DS(ON) n Current Mode Operation for Excellent Line mode architecture and external compensation allow the and Load Transient Response transient response to be optimized over a wide range of n Short-Circuit Protected loads and output capacitors. n Low Dropout Operation: 100% Duty Cycle The LTC3565 can be configured for automatic power n Low Shutdown Current: I 1A Q saving Burst Mode operation (I = 40A) to reduce gate Q n Output Voltages from 0.6V to 5V charge losses when the load current drops below the level n Synchronizable to External Clock required for continuous operation. For reduced noise and n Supports Pre-Biased Outputs RF interference, the SYNC/MODE pin can be configured to n Small 10-Lead (3mm 3mm) DFN or MSOP Package skip pulses or provide forced continuous operation. To further maximize battery life, the P-channel MOSFET APPLICATIONS is turned on continuously in dropout (100% duty cycle). n Notebook Computers In shutdown, the device draws <1A. n Digital Cameras L, LT, LTC, LTM, Linear Technology the Linear logo, Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. Hot Swap and ThinSOT are trademarks of Linear n Cellular Phones Technology Corporation. All other trademarks are the property of their respective owners. n Protected by U.S. Patents including 5481178, 6580258, 6498466, 6611131. Handheld Instruments n Board Mounted Power Supplies TYPICAL APPLICATION Step-Down 2.5V/1.25A Regulator Efficiency and Power Loss vs Output Current V 100 1 IN 2.5V TO 5.5V 90 80 22F 0.1 70 SV PV IN IN SYNC/MODE 60 RUN 2.2H V OUT 50 0.01 PGOOD SW 2.5V LTC3565 1.25A 40 ITH 22F RT 30 22pF 0.001 12.1k V = 2.7V 20 IN V V = 3.6V FB IN 931k 10 GND V = 4.2V IN 680pF 0 0.0001 191k 294k 0.1 1 10 100 1000 10000 OUTPUT CURRENT (mA) 3565 TA01a 3565 TA01b 3565fc 1 For more information www.linear.com/LTC3565 EFFICIENCY (%)LTC3565 ABSOLUTE MAXIMUM RATINGS (Note 1) PV , SV Voltages .................................... 0.3V to 6V Operating Junction Temperature Range IN IN V , ITH Voltages ......................... 0.3V to (V + 0.3V) (Notes 2, 5, 8) ........................................ 40C to 125C FB IN SYNC/MODE, PGOOD Voltage ..... 0.3V to (V + 0.3V) Storage Temperature Range .................. 65C to 125C IN SW Voltage (DC) .......................... 0.3V to (V + 0.3V) Lead Temperature (Soldering, 10 sec) ...................300C IN RUN Voltage ................................................ 0.3V to 6V PIN CONFIGURATION TOP VIEW TOP VIEW 10 RT 1 ITH RT 1 10 ITH RUN 2 9 V FB RUN 2 9 V FB 11 11 SYNC/MODE 3 8 PGOOD SYNC/MODE 3 8 PGOOD GND GND SW 4 7 SV IN SW 4 7 SV IN GND 5 6 PV IN GND 5 6 PV IN MSE PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE T = 125C, = 40C/W, = 10C/W JMAX JA JC 10-LEAD (3mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 43C/W, = 7.5C/W JMAX JA JC 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 LTC3565EDD PBF LTC3565EDD TRPBF LDNR 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3565IDD PBF LTC3565IDD TRPBF LDNR 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3565EMSE PBF LTC3565EMSE TRPBF LTDVJ 10-Lead Plastic MSOP 40C to 125C LTC3565IMSE PBF LTC3565IMSE TRPBF LTDVJ 10-Lead Plastic MSOP 40C to 125C 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: