AP3008

Preliminary Datasheet WHITE LED DRIVER General Description The AP3008 is a 1.2MHz PWM boost switching regulator designed for constant-current white LED driver applications. The AP3008 can drive a string of 2 to 3 white LEDs from a 2.7V supply in series, ensuring uniform brightness and eliminating several ballast resistors. The AP3008 implements a constant frequency 1.2MHz 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 95 mV, which reduces the power dissipation in the current setting resistor. The AP3008 is equipped with OVP protection ability, the SW pin monitors the output voltage and will turn off the device if an over-voltage condition is present to prevent damage from an open circuit condition. The AP3008 is available in SOT-23-5L package. AP3008 Features · · · · · · · · Inherently Uniform LED Current High Efficiency up to 84% Drives 2 to 3 LEDs from a 2.7V Supply 1.2MHz PWM Operation Frequency Requires Only 0.22µF Output Capacitor Shutdown Current: < 1µA Built-in Output Over-Voltage Protection Under Voltage Lock Out (UVLO) Applications · · · · · Digital Cameras LCD modules GPS Receivers Cellular Phones PDAs, Handheld Computers SOT-23-5L Figure 1. Package Type of AP3008 Jul. 2006 Rev. 1. 3 1 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Pin Configuration K Package (SOT-23-5L) AP3008 SW GND FB 1 2 3 5 VIN 4 SHDN Figure 2. Pin Configuration of AP3008 (Top View) Pin Description Pin Number 1 Pin Name SW Function Switch Pin. Connect inductor/diode here. The output voltage can range up to 29V but not extend this limit. If the voltage on this pin is higher than the overvoltage protection threshold (OVP), the device comes back to shutdown mode. To restart the chip, one must then send a low to high sequence on shutdown pin or switch off the VIN supply. Ground Pin. Voltage Feedback. Reference voltage is 95mV. Shutdown Pin. Connect to 1.5V or higher to enable device; Connect to 0.4V or less to disable device. Input Supply Pin. Must be locally bypassed. 2 3 4 5 GND FB SHDN VIN Jul. 2006 Rev. 1. 3 2 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Functional Block Diagram AP3008 OVP 1 DRIVER SW FB VIN 3 5 VREF 1.25V 95mV A1 A2 COMPARATOR R S Q Q1 Σ 2 SHDN 4 GND SHUTDOWN RAMP GENERATOR 1.2MHz OSCILLATOR Figure 3. Functional Block Diagram of AP3008 Ordering Information AP3008 Circuit Type Package K: SOT-23-5L E1: Lead Free Blank: Tin Lead TR: Tape and Reel Blank: Tube Package SOT-23-5L Temperature Range -40 to 85oC Part Number Tin Lead AP3008KTR Marking ID Tin Lead K1B Lead Free AP3008KTR-E1 Lead Free E1B Packing Type Tape & Reel BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant. Jul. 2006 Rev. 1. 3 3 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Absolute Maximum Ratings (Note 1) Parameter Input Voltage SW Voltage FB Voltage SHDN Voltage Thermal Resistance (Junction to Atmosphere, no Heat sink) Operating Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10sec) ESD (Machine Model) ESD (Human Body Model) TSTG TLEAD RθJA Symbol VIN Value 15 36 10 15 265 150 -65 to 150 260 250 2000 Unit V V V V oC/W oC oC oC AP3008 V V Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods may affect device reliability. Recommended Operating Conditions Parameter Operating Temperature Range Operating Voltage Range Symbol TOP Min -40 2.5 Max 85 12 Unit oC V Jul. 2006 Rev. 1. 3 4 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Electrical Characteristics (VIN=3V, VSHDN=3V, TA=25oC, unless otherwise specified.) Parameter Feedback Voltage FB Pin Bias Current Supply Current Supply Current Switch Frequency Maximum Duty Cycle Switch Current Limit Switch VCESAT Switch Leakage Current VTH SHDN Voltage SHDN Pin Bias Current OVP Voltage VOVP VTL ICC IQ f DMAX ILIM VCESAT Duty=15% ISW=250mA VSW=5V High Low 50 29 1.5 0.4 V µA V VSHDN=VIN, VFB=VIN, No switching VSHDN=0V 0.8 85 Symbol VFB Conditions ISW=100mA, Duty Cycle=66% Min 86 Typ 95 45 1.9 0.1 1.2 90 320 350 0.01 5 Max 104 100 2.5 1.0 1.6 Unit mV nA mA µA MHz % mA mV µA AP3008 Jul. 2006 Rev. 1. 3 5 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Typical Performance Characteristics AP3008 2.8 2.6 2.4 2.2 2.0 1.8 320 280 240 200 160 120 80 40 0 2 4 6 8 10 IQ (mA) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -50 C o 25 C o 100 C o SHDN Pin Bias Current (µA) VSHDN=10V VSHDN=3.6V VSHDN=3V VSHDN=2.7V -50 -25 0 25 50 o 75 100 VIN (V) Junction Temperature ( C) Figure 4. Quiescent Current vs. VIN Figure 5. SHDN Pin Bias Current vs. Junction Temperature 55 1.4 1.2 50 45 Feedback Bias Current (nA) -25 0 25 50 o Switch Frequency (MHz) 40 35 30 25 20 15 10 5 1.0 0.8 0.6 0.4 0.2 0.0 -50 75 100 0 -50 -25 0 25 50 o 75 100 Junction Temperature ( C) Junction Temperature ( C) Figure 6. Switch Frequency vs. Junction Temperature Figure 7. Feedback Bias Current vs. Junction Temperature Jul. 2006 Rev. 1. 3 6 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Typical Performance Characteristics (Continued) AP3008 440 84 400 ILED=20mA 360 320 Current Limit (mA) 50 o Efficiency (%) 82 280 240 200 160 120 80 40 ILED=15mA 80 ILED=10mA VIN=3.6V 3 LEDs 78 -50 -25 0 25 75 100 0 0 20 40 60 80 100 Junction Temperature ( C) Duty Cycle (%) Figure 8. Efficiency vs. Junction Temperature Figure 9. Switch Current vs. Duty Cycle 85 85 80 3 LEDs o VLED=3.35V, TA=25 C 80 4 LEDs o VLED=3.35V, TA=25 C Efficiency (%) Efficiency (%) 75 VIN=3V VIN=3.6V 75 VIN=3V VIN=3.6V 70 70 65 65 60 0 5 10 15 20 60 0 5 10 15 20 LED Current (mA) LED Current (mA) Figure 10. Efficiency vs. LED Current Figure 11. Efficiency vs. LED Current Jul. 2006 Rev. 1. 3 7 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Typical Application AP3008 VIN 3V to 5V L1 22µΗ D1 LED 1 LED 2 OFF ON SHDN C1 1 µF VIN SW LED 3 FB R1 6.34Ω C2 0.22µF AP3008 GND C1, C2: X5R or X7R Dielectric L1: SUMIDA CDRH5D28R-220NC or Equivalent Figure 12. Three White LEDs Driver Jul. 2006 Rev. 1. 3 8 BCD Semiconductor Manufacturing Limited Preliminary Datasheet WHITE LED DRIVER Mechanical Dimensions SOT-23-5L Unit: mm(inch) AP3008 2.820(0.111) 3.020(0.119) 0.100(0.004) 0.200(0.008) 2.650(0.104) 2.950(0.116) 1.500(0.059) 1.700(0.067) 0.200(0.008) 0.700(0.028) REF 0.300(0.012) 0.600(0.024) 0.950(0.037) TYP 0.300(0.012) 0.400(0.016) 1.800(0.071) 2.000(0.079) 0° 8° 1.050(0.041) 1.250(0.049) 0.000(0.000) 0.100(0.004) 1.050(0.041) 1.150(0.045) Jul. 2006 Rev. 1. 3 9 BCD Semiconductor Manufacturing Limited http://www.bcdsemi.com IMPORTANT NOTICE BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifications herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or other rights nor the rights of others. MAIN SITE BCD Semiconductor Manufacturing Limited - Wafer Fab Shanghai SIM-BCD Semiconductor Manufacturing Limited 800, Yi Shan Road, Shanghai 200233, China Tel: +86-21-6485 1491, Fax: +86-21-5450 0008 BCD Semiconductor Manufacturing Limited - IC Design Group Advanced Analog Circuits (Shanghai) Corporation 8F, Zone B, 900, Yi Shan Road, Shanghai 200233, China Tel: +86-21-6495 9539, Fax: +86-21-6485 9673 REGIONAL SALES OFFICE Shenzhen Office Shanghai SIM-BCD Semiconductor Manufacturing Co., Ltd. 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