AP3031KTR-G1

Data Sheet WHITE LED STEP-UP CONVERTER AP3031 General Description Features The AP3031 is an inductor-based DC/DC boost converter designed to drive LED arrays. 1.4A switching current allows AP3031 to be used in different 7' to 10' LCD panel backlights (3*13 LED arrays typically). · Up to 92% Efficiency (VIN=9V, IOUT=260mA) · Up to 84% Efficiency (VIN=5V, IOUT=260mA) A constant frequency 1MHz PWM control scheme is employed in this IC, which means tiny external components can be used. Specifically, 1mm tall 4.7μH inductor and 0.47μF output capacitor for the typical application is sufficient. · · · · · · · Fast 1MHz Switching Frequency Wide Input Voltage Range: 2.7V to 16V Low 200mV Feedback Voltage Output Over Voltage Protection Cycle by Cycle Current Limit: 1.4A Built-in Soft-start Built-in Standby Mode to Achieve High Frequency PWM Dimming Built-in Thermal Shutdown Function Under Voltage Lockout The over output voltage protection is equipped in AP3031, which protects the IC under open load condition. The AP3031 includes UVLO, soft-start, current limit and OTSD to protect the circuit. · · The AP3031 is available in standard SOT-23-6, TSOT23-6 and SOIC-8 packages. Applications · · · · · SOT-23-6 7' to 10' LCD Panels Digital Photo Frame GPS Receiver EPC PDVD TSOT-23-6 SOIC-8 Figure 1. Package Types of AP3031 Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 1 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Pin Configuration K/KT Package (SOT-23-6/TSOT-23-6) M Package (SOIC-8) Pin 1 Mark SW 1 6 VIN GND 2 5 OV FB 3 4 CTRL FB 1 8 CTRL GND 2 7 OV GND 3 6 GND SW 4 5 VIN Figure 2. Pin Configuration of AP3031 (Top View) Pin Description Pin Number 6-Pin 8-Pin Pin Name 1 4 SW 2 2, 3, 6 GND 3 1 FB Function Switch Pin. Connect external inductor and Schottky Ground Pin Voltage Feedback Pin. Reference voltage is 200mV Enable and Dimming Control Pin. Connect to a high input to enable the IC or a low input to disable the IC. If logic low time is more than about 0.7ms and then enable the IC, the AP3031 will soft start to protect system departments. If logic low time is less than about 0.7ms and then enable the IC, the AP3031 will hold on standby mode and start directly to achieve high frequency dimming 4 8 CTRL 5 7 OV Over-voltage Protection Input Pin. Connect to the output directly. On OVP condition, the output voltage will be clamped 6 5 VIN Input Supply Pin. Must be locally bypassed Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 2 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Functional Block Diagram FB SW 3 (1) 1 (4) SOFT START 5 (7) OV VIN 6 (5) V REF 1 .25 V DRIVER A1 200 mV A2 CONTROL LOGIC COMPARATOR OVER TEMPERATURE DETECTOR Q1 2 (2, 3, 6) Σ 4 (8) CTRL STANDBY To Control Logic OV GND RAMP GENERATOR 1 MHz OSCILLATOR A (B) A SOT-23-6/TSOT-23-6 B SOIC-8 Figure 3. Functional Block Diagram of AP3031 Ordering Information AP3031 - Circuit Type G1: Green Package K: SOT-23-6 KT: TSOT-23-6 M: SOIC-8 Package Temperature Range SOT-23-6 TSOT-23-6 SOIC-8 -40 to 85oC TR: Tape and Reel Blank: Tube Part Number Marking ID Packing Type AP3031KTR-G1 GEC Tape & Reel Tape & Reel AP3031KTTR-G1 L1E AP3031M-G1 3031M-G1 Tube AP3031MTR-G1 3031M-G1 Tape & Reel BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant and green. Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 3 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Absolute Maximum Ratings (Note 1) Parameter Symbol Value Unit Input Voltage VIN 20 V SW Voltage VSW 38 V FB Voltage VFB 20 V VCTRL 20 V CTRL Voltage SOT-23-6/TSOT-23-6 265 SOIC-8 120 Thermal Resistance (Junction to Ambient, No Heat Sink) θJA Operating Junction Temperature TJ 150 oC TSTG -65 to 150 oC TLEAD 260 o ESD (Machine Model) 600 V ESD (Human Body Model) 4000 V Storage Temperature Range Lead Temperature (Soldering, 10sec) oC/W C 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 Symbol Min Max Operating Temperature Range TOP -40 85 o Input Voltage VIN 2.7 16 V CTRL Voltage VCTRL 16 V Dec. 2012 Rev. 1. 6 Unit C BCD Semiconductor Manufacturing Limited 4 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Electrical Characteristics (VIN=5.0V, VCTRL =5.0V, TA=25oC, unless otherwise specified.) Parameter Symbol Operating Voltage VIN Feedback Voltage (Note 2) VFB FB Pin Bias Current IFB Quiescent Current IQ Shutdown Quiescent Current ISHDN Conditions Min Typ Max Unit 16 V 200 212 mV 35 100 nA 2.7 IOUT=20mA, 3 LEDs, TA=-40oC to 85oC 188 VFB=VIN, no switching 3.0 4.0 5.0 mA VCTRL=0V 20 50 80 μA 1.3 MHz Switching Frequency f 0.75 1 Maximum Duty Cycle DMAX 90 93 % Switch Current Limit (Note 3) ILIMIT 1.2 1.4 A Switch VCE Saturation Voltage VCESAT ISW=0.6A 300 mV VSW=16V 0.01 Switch Leakage Current CTRL Pin Voltage VCTRL D=60% Active high 5 1.8 μA V Active low 0.5 CTRL Pin Bias Current ICTRL 35 60 85 μA OVP Voltage VOVP 15.5 17.5 19.5 V Soft-start Time tSS 250 μs Standby Time tSTB 0.7 ms Thermal Shutdown TOTSD 155 oC Thermal Resistance (Junction to Case) θJC 60 oC/W Note 2: The bold type specifications of full temperature range are guaranteed by design (GBD). Note 3: The switch current limit is related to duty cycle. Please refer to Figure 15 for detail. Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 5 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Typical Performance Characteristics 90 95 85 90 80 85 75 80 Efficiency (%) Efficiency (%) (WLED forward voltage (VF)=3.2V at IF=20mA, unless otherwise noted.) 70 65 60 75 70 65 o 55 VIN=5V, VOUT=10V, TA=25 C 60 50 CIN=10μF, COUT=0.47μF, L=4.7μH 55 45 0 o VOUT=10V, IOUT=260mA,TA=25 C CIN=10μF, COUT=0.47μF, L=4.7μH 50 3.5 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 4.0 4.5 5.0 5.5 6.5 7.0 7.5 8.0 8.5 9.0 Figure 4. Efficiency vs. Output Current Figure 5. Efficiency vs. Input Voltage 4.7 2.65 4.6 2.60 4.5 Quiescent Current (mA) 2.70 2.55 2.50 2.45 2.40 2.35 4.4 4.3 4.2 4.1 4.0 o TA= -40 C 2.30 3.9 TA= 25 C 2.25 3.8 TA= 85 C 2.20 -60 3.7 -40 -20 0 20 40 60 9.5 Input Voltage (V) Output Current (mA) Minimum Operating Voltage (V) 6.0 80 100 120 140 o o 2 4 6 8 10 12 14 16 Input Voltage (V) o Temperature ( C) Figure 6. Minimum Operating Voltage vs. Temperature Figure 7. Quiescent Current vs. Input Voltage Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 6 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Typical Performance Characteristics (Continued) 85 2.0 80 1.8 75 CTRL Pin Voltage (V) Shutdown Quiescent Current (μA) (WLED forward voltage (VF)=3.2V at IF=20mA, unless otherwise noted.) 70 65 60 55 o TA= -40 C 50 1.4 1.2 1.0 0.8 o TA= 25 C 0.6 o 45 40 1.6 TA= 85 C 2 4 6 8 10 12 14 0.4 -60 16 -40 -20 0 60 80 100 120 140 Figure 9. CTRL Pin Voltage vs. Temperature 212 220 210 200 208 Feedback Voltage (mV) 180 CTRL Pin Current (μA) 40 o Figure 8. Shutdown Quiescent Current vs. Input Voltage 160 140 120 100 80 60 206 204 202 200 198 196 194 192 40 20 20 Temperature ( C) Input Voltage (V) IOUT= 20mA 190 2 4 6 8 10 12 14 16 188 -60 18 -40 -20 0 20 40 60 80 100 120 140 o Temperature ( C) CTRL Pin Voltage (V) Figure 10. CTRL Pin Current vs. CTRL Pin Voltage Figure 11. Feedback Voltage vs. Temperature Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 7 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Typical Performance Characteristics (Continued) (WLED forward voltage (VF)=3.2V at IF=20mA, unless otherwise noted.) 20 1.4 1.3 19 OVP Voltage (V) Frequency (MHz) 1.2 1.1 1.0 0.9 18 17 16 0.8 15 0.7 0.6 -60 -40 -20 0 20 40 60 80 100 120 14 -60 140 -40 -20 0 1.20 2.0 1.15 1.9 Switch Current Limit (A) Frequency (MHz) 1.10 1.05 1.00 0.95 0.90 0.85 12 140 14 16 o o 1.6 1.5 1.4 1.3 1.0 10 18 o TA=-40 C TA=85 C 1.1 10 120 1.7 0.75 8 100 TA=25 C 1.2 6 80 1.8 0.80 4 60 Figure 13. OVP Voltage vs. Temperature Figure 12. Frequency vs. Temperature 2 40 o Temperature ( C) 0.70 20 Temperature ( C) o 20 30 40 50 60 70 80 90 Duty Cycle (%) Input Voltage (V) Figure 15. Switch Current Limit vs. Duty Cycle Figure 14. Frequency vs. Input Voltage Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 8 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Typical Performance Characteristics (Continued) 650 80 600 75 550 70 500 Case Temperature ( C) 450 o Switch Saturation Voltage (mV) (WLED forward voltage (VF)=3.2V at IF=20mA, unless otherwise noted.) 400 350 300 250 200 o TA=-40 C 150 o TA=25 C 100 o TA=85 C 50 0 0.0 65 60 55 50 45 VIN=5V, VOUT=10V, TA=25 C 35 CIN=10μF, COUT=0.47μF, L=4.7μH 30 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 o 40 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 Output Current (mA) Switch Current (A) Figure 16. Switch Saturation Voltage Figure 17. Case Temperature vs. Output Current vs. Switch Current Dec. 2012 Rev. 1. 6 BCD Semiconductor Manufacturing Limited 9 Data Sheet WHITE LED STEP-UP CONVERTER AP3031 Application Information Soft Start The AP3031 has an internal soft start circuit to limit the inrush current during startup. If logic low time on CTRL pin is more than about 0.7ms and then enable the IC, the AP3031 will start smoothly to protect the supplier. The time of startup is controlled by internal soft-start capacitor. Details please refer to Figure 18. Operation The AP3031 is a boost DC-DC converter which uses a constant frequency, current mode control scheme to provide excellent line and load regulation. Operation can be best understood by referring to Figure 3 and Figure 24. At the start of each oscillator cycle, switch Q1 turns on. The switch current will increase linearly. The voltage on sense resistor is proportional to the switch current. The output of the current sense amplifier is added to a stabilizing ramp and the result is fed into the noninversion input of the PWM comparator A2. When this voltage exceeds the output voltage level of the error amplifier A1, the switch is turned off. >0.7ms VCTRL 5V/div VSW 5V/div IL 500mA/div VOUT 10V/div Time 80μs/div It is clear that the voltage level at inversion input of A2 sets the peak current level to keep the output in regulation. This voltage level is the output signal of error amplifier A1, and is the amplified signal of the voltage difference between feedback voltage and reference voltage of 200mV. So, a constant output current can be provided by this operation mode. LED Current Control Refer to Figure 24, the LED current is controlled by the feedback resistor RISET. LEDs' current accuracy is determined by the feedback voltage and resistor RISET, so the precise resistors are preferred. The resistance of RISET is in inverse proportion to the LED current since the feedback reference is fixed at 200mV. The relation for RISET and LED current (ILED)can be expressed as below: R ISET Figure 18. Soft-start Waveform VIN=5V, 3×13 LEDs, ILED=260mA Standby and Dimming To avoid audio noise and achieve high frequency dimming, AP3031 is equipped with standby function. If logic low time on CTRL pin is less than about 0.7ms and then enable the IC, the AP3031 will hold on standby mode and start directly to achieve high frequency dimming. Details please refer to Figure 19. VCTRL 5V/div