LT3663 Typical perForMance characTerisTics TA = 25°C, unless otherwise noted.Switch Voltage DropBoost Diode VfBOOST Pin Current 400 1.4 35 125°C 350 1.2 30 25°C 300 1 25 (V) F 250 –45°C 0.8 20 TAGE DROP (mV) 200 0.6 15 150 BOOST DIODE V 0.4 10 100 BOOST PIN CURRENT (mA) SWITCH VOL 0.2 5 50 0 0 0 0 0.2 0.4 0.6 0.8 1 1.2 0 50 100 150 200 250 300 0 0.2 0.4 0.5 0.8 1.0 1.2 SWITCH CURRENT (A) DIODE CURRENT (mA) SWITCH CURRENT (A) 3663 G01 3653 G09 3653 G07 pin FuncTionsBOOST: The BOOST pin is used to provide a drive voltage, RUN: The Run pin is used to put the LT3663 into shutdown higher than the input voltage, to the internal power switch. mode. Tie to ground to shut down the LT3663. Tie to 2.5V The BOOST pin is also internal y connected to the cathode or more for normal operation. If the shutdown feature is of the BOOST diode. not used, connect this pin to VIN. GND (Exposed Pad Pin 9) : Ground. The exposed pad SW: The SW pin is the output of the internal power switch. must be soldered to the PCB and electrical y connected Connect this pin to the inductor, catch diode and boost to ground. Use a large ground plane and thermal vias to capacitor. optimize thermal performance. VIN: The VIN pin supplies current to the LT3663’s internal FB (LT3663): The LT3663 regulates the FB pin to 0.8V. regulator and internal power switch. Capacitively bypass Connect the feedback resistor divider tap to this pin. the pin to ground. ILIM: Output Current Limit Program Pin. Connect a resistor VOUT: The VOUT pin is connected to the negative terminal to ground to program the regulator output current limit. of the internal output current limit sense resistor. ISENSE: The ISENSE pin is the positive input to the internal VOUTS (LT3663-X): Output Voltage Sense Pin. Connect to output current limit sense resistor. The ISENSE pin is also the positive terminal of the output capacitor. the anode to the internal BOOST diode. 3663fc For more information For more information www.linear.com/LT3663 5 Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Operation Applications Information Package Description