Preliminary Datasheet LP3308 1.4MHz,30V/1.3A High Performance, Boost Converter Features General Description The LP3308 is a 1.4MHz PWM boost switching regulator designed for constant-voltage boost applications. The LP3308 can drive a string of up to 30V. The LP3308 implements a constant frequency 1.4MHz PWM control scheme. The high frequency PWM operation also saves board space by reducing external component sizes. To improve efficiency, the feedback voltage is set to 1230 mV, which reduces the power dissipation in the voltage setting resistor. Highly integration and internal compensation network minimizes as 5 external component counts. Optimized operation frequency can meet the requirement of small LC filters value and low operation current with high efficiency. High Efficiency: 90% 1.4MHzFixed-Frequency PWM Operation Maximum Output Voltage up to 30V Guaranteed 13V/200mA Output with 5V input Operating Range : 2.7V to 5.5V Shutdown Supply Current:<1uA Programmable Soft-star Available in TSOT23-6/SOT23-5 Package Minimize the External Component RoHS Compliant and 100% Lead (Pb)-Free Applications Panel Bais Voltage supply OLED Backlight driver Notebook Computers Portable Applications MID/PTV Ordering Information LP3308 Typical Application Circuit Vin F: Pb-Free Pin Configurations 6 1 D1 SS0520 LX LP3308 FB SHDN SS R1 860K 3 5 R2 100K C4 33nF 2 4 C2 4.7uF C3/NC 100pF Vin GND Package: B5: SOT23-5 B6: TSOT23-6 10uH C1 4.7uF Marking information (TSOT23-6) Please view website. (SOT23-5) LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com Page 1 of 9 Preliminary Datasheet LP3308 Functional pin description SOT-23-5 SOT-23-6 Pin Name Pin Function 1 1 LX Switch Pin. Connect this Pin to inductor and catch diode. Minimize the track area to reduce EMI. 2 2 GND Ground Pin 3 3 FB Feedback Reference Voltage Pin. Series connect a resistor between Vout and ground as a voltage sense. The feedback voltage is 1230mV. 4 /SHDN Chip Enable (Active High). Voltage sensing input to trigger the function of over voltage protection. Note that this pin is high impedance. There should be a pull low 100kΩ resistor connected to GND when the control signal is floating. 5 SS Softstar pin. Leave SS open to disable the soft-star function. 6 Vin Supply Input Voltage Pin. Bypass 1uF capacitor to GND to reduce the input noise. 4 5 Function Block Diagram LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com Page 2 of 9 Preliminary Datasheet LP3308 Absolute Maximum Ratings Supply Input Voltage---------------------------------------------------------------------------------------------------−0.3V to 6.0V LX Input Voltage --------------------------------------------------------------------------------------------------------−0.3V to 33V The Other Pins ----------------------------------------------------------------------------------------------------------−0.3V to 5.5V Power Dissipation, PD @ TA = 25°C TSOT-23-5/6-----------------------------------------------------------------------0.455W Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------------- 260°C Operation Temperature Range ---------------------------------------------------------------------------------−40°C to 80°C Storage Temperature Range ----------------------------------------------------------------------------------------−65°C to 150°C Electrical Characteristics Parameter Symbol Test Condition Min Typ. Max Units 6 V System Supply Input Operation voltage Range VDD 2.7 Under Voltage Lock Out VDD 2.2 Supply Current IDD FB=0.2V, Switch 430 550 uA Shut Down Current IDD VEN < 0.4V 0.1 1 uA Line Regulation VIN : 3.0~4.3V 2.4 2.6 V 2 % 1.4 MHz Oscillator Operation Frequency FOSC Maximum Duty Cycle Feedback Voltage 93 LP3308 1.21 % 1.23 1.255 V MOSFET On Resistance of MOSFET RDS(ON) 0.7 Ω SW Current Limit ILM 1.4 A Protection Shut Down Voltage VEN Enable on Voltage VEN LP3308– 00 Version1.0 Datasheet Feb.-2010 0.3 V 1.0 www.lowpowersemi.com V Page 3 of 9 Preliminary Datasheet LP3308 Typical Operating Characteristics LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com Page 4 of 9 Preliminary Datasheet LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com LP3308 Page 5 of 9 Preliminary Datasheet LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com LP3308 Page 6 of 9 Preliminary Datasheet LP3308 Applications Information Inductor Selection The recommended value of inductor for 30V applications are 4.7 to 22µH. Small size and better efficiency are the major concerns for portable device, such as LP3308 used for mobile phone. The inductor should have low core loss at 1.4MHz and low DCR for better efficiency. To avoid inductor saturation current rating should be considered. LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com Page 7 of 9 Preliminary Datasheet LP3308 Packing information LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com Page 8 of 9 Preliminary Datasheet LP3308– 00 Version1.0 Datasheet Feb.-2010 www.lowpowersemi.com LP3308 Page 9 of 9