FL7701 Smart LED Lamp Driver IC with PFC function Features Description Digitally Implemented Active PFC Function (No Additional Circuit Necessary for High PF) Built-in HV Supplying Circuit: Self Biasing The FL7701 LED lamp driver is a simple IC with PFC function. The special “adopted digital” technique of the IC can automatically detect input voltage condition and send an internal reference signal for achieving high power factor. When AC input is applied to the IC, PFC function is automatically enabled. Otherwise, when DC input is applied to the IC, PFC function is automatically disabled. The FL7701 does not need a bulk capacitor (electrolytic capacitor) for supply rail stability, which can significantly affect to LED lamp system. AOCP Function with Auto-Restart Mode Built-in Over-Temperature Protection Function Cycle-by-Cycle Current Limit Current-Sense Pin Open Protection Low Operating Current: 0.85mA (Typical) Under-Voltage Lockout with 5V Hysteresis Programmable Oscillation Frequency Programmable LED Current Analog Dimming Function Soft-Start Function Precise Internal Reference: ±3% Applications LED Lamp for Decorative Lighting LED Lamp for Low-Power Lighting Ordering Information Part Number Operating Temperature Range FL7701M -40°C to +125°C FL7701MX © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 Package 8-Lead, Small Outline Integrated Circuit (SOIC), JEDEC MS-012, .150-inch Narrow Body Packing Method Tube Tape & Reel www.fairchildsemi.com FL7701 — Smart LED Lamp Driver IC with PFC Function October 2011 FL7701 — Smart LED Lamp Driver IC with PFC Function Application Diagram LED EMI filter BD FRD AC INPUT L HV ADIM OUT RT VCC FL7701 CS GND Figure 1. Typical Application Block Diagram HV VCC JFET VCC ZCD UVLO time IAD ZCD ADIM DAC TSD Soft start Digital Block RT S Oscillator OUT Q R Reference + LEB GND CS Leading Edge Blanking + AOCP 2.5V Figure 2. Block Diagram © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 2 Figure 3. Pin Configuration Pin Definitions Pin # Name Description 1 CS 2 OUT OUT. Connects to the MOSFET gate. 3 VCC VCC. Supply pin for stable IC operation and used for detecting the ZCD signal for internal artificial reference. 4 RT 5 ADIM Analog Dimming. Connects to the internal current source to change output current using an external resistor; connect a small capacitor in non-dimming condition. 6 GND GROUND. Ground for the IC. 7 NC No Connection 8 HV High Voltage. Connects to the high voltage line and supplies current to the IC Current Sense. Limits output current, depending on the sensing resistor voltage. RT. This pin allows for programmable operating frequency using an external resistor. If this pin is not connected, the IC operates with a set fixed frequency. © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 3 FL7701 — Smart LED Lamp Driver IC with PFC Function Pin Configuration Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Parameter Min. Max. Unit VCC IC Supply Voltage 20 V HV High Voltage Sensing 500 V IO+/IO- Peak Drive Output Current (Sourcing / Sinking) 250 mA VADIM Analog Dimming 5 V VRT RT Pin Voltage 5 V VCS Allowable Current Sensing Detection Voltage 5 V TA Operating Ambient Temperature Range -40 +125 C TJ Operating Junction Temperature -40 +150 C -65 +150 C 135 C/W 660 mW TSTG Storage Temperature Range θJA Thermal Resistance Junction-Air PD Power Dissipation ESD (1,2) Electrostatic Discharge Capability Human Body Model, JESD22-A114 2000 Charged Device Model, JESD22-C101 1000 V Notes: 1. Thermal resistance test board. Size: 76.2mm x 114.3mm x 1.6mm (1S0P); JEDEC standard: JESD51-2, JESD51-3. 2. Assume no ambient airflow. © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 4 FL7701 — Smart LED Lamp Driver IC with PFC Function Absolute Maximum Ratings Typical values are at TA = +25°C. Specifications to -40°C ~ 125°C are guaranteed by design based on final characterization results. Symbol Parameter Conditions Min. Typ. Max. Unit VCC Bias Section VCC VCC Regulator Output Voltage VHV=100Vdc 14.0 15.5 17.0 V VCCST+ UVLO Positive Going Threshold VCC Increasing 12 13 14 V VCCST- UVLO Negative Going Threshold VCC Decreasing 7 8 9 V VCCHY UVLO Hysteresis 4 5 6 V 0.85 1.10 mA 120 150 μA IHV HV Pin Current IST Startup Current VHV=100VDC, CL=150pF, RT=Open Switching Section fOSC tMIN DMAX Operating Frequency RT=5.95kΩ 200 250 300 kHz RT=87kΩ 16 20 24 kHz RT Open 40.5 45.0 49.5 kHz Minimum On Time Maximum Duty Cycle (3) 400 ns 50 % tLEB Leading Edge Blanking Time 350 ns VRT Voltage Reference of RT pin 1.5 V Soft-Start Section tss DC Mode Soft-Start Time(3) 48 AC Mode 60 72 ms 7 Periods Reference Section VCS1 VCS2 Internal Reference Voltage of CS Pin DC Mode (3) AC Mode 0.354 0.365 0.376 0.485 0.500 0.515 17.7 18.7 19.7 V Protection Section OVPVCC Over-Voltage Protection on VCC Pin (3) V VAOCP Abnormal OCP Level at CS Pin 2.5 V tAOCP Abnormal Detection Time(3) 70 ns tTSDH Thermal Shutdown Threshold(3) 150 °C tTSDHY Thermal Shutdown Threshold (3) Hysteresis 50 °C 140 Dimming Section Analog Dimming Positive Going VADIM(ST+) Threshold(3) Analog Dimming Negative Going VADIM(ST-) Threshold(3) IAD 3.15 Internal Current Source for ADIM Pin 9 3.50 3.85 V 0.50 0.75 V 12 15 μA Note: 3. These parameters, although guaranteed, are not 100% tested in production. © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 5 FL7701 — Smart LED Lamp Driver IC with PFC Function Electrical Characteristics The FL7701 is a basic PWM controller for buck converter topology in Continuous Conduction Mode (CCM) with intelligent PFC function using a digital control algorithm. The FL7701 has an internal selfbiasing circuit that uses the high-voltage switching device. The IC does not need an auxiliary powering path to the VCC pin typical in flyback control ICs or PSR product family. 2. Internal PFC Function: How to Achieve High Power Factor The FL7701 has a simple, but smart, internal PFC function that does not require additional detection pins, other components, or an electrolytic capacitor for supply voltage stabilization. The FL7701 application does not use the rectification capacitor after the bridge diode. The VCC pin, which is supplies power for the IC, has high voltage ripple as well as the rectification voltage after bridge. Using this kind of voltage fluctuation on the VCC pin, the IC estimates the input voltage phase for the internal reference signal. When the input voltage applied to the HV pin is over 25V to 500V, the FL7701 maintains a 15.5V DC voltage at the VCC pin for stable operation. The FL7701 UVLO block functions such that when the VCC voltage rises higher than VCCST+, the internal UVLO block releases and starts operation. Otherwise the VCC goes down to the VCCST- and IC operation stops. Normally, the hysteresis function provides stable operation even if the input voltage is operating under the very noisy or unstable circumstances. For precise and reliable calculation of input voltage phase using the VCC pin, the FL7701 uses a digital technique (sigma/delta modulation/demodulation). After finishing the digital technique, the FL7701 has a new reference that is the same phase with input voltage as shown in Figure 5. This signal enters the final comparator and is compared with current information from the sensing resistor. The result is a high power factor (PF). The FL7701 has a smart internal digital block for determining input condition. When an AC source with 50Hz or 60Hz is applied to the IC, the IC automatically changes its internal reference signal, which is similar to input signal, for creating high power factor. Otherwise, once the DC source connects to the IC, the internal reference immediately changes to DC. 1. Soft-Start Function The FL7701 has an internal soft-start function to reduce inrush current at startup. When the IC starts operation following an internal sequence, the internal reference slowly increases for a pre-determined fixed time. After this transient period, the internal reference goes to a steady-state level. In this time, the IC continually tries to find phase information from the VCC pin. If the IC succeeds in getting phase information, it automatically follows a similar shape reference made during the transient times, 7 periods. If not, the IC has a DC reference level. Figure 5. Internal PFC Function 3. IC Operation The self-biasing function of FL7701, using an HV device, supplies enough operating current to the IC for constant startup time in wide range of input conditions. If an LED does not connect to the system, the IC cannot start. In the event of a load short circuit, the IC operates with a very low duty cycle to avoid malfunction. Figure 4. Soft Starting Function in AC Input Mode © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 6 FL7701 — Smart LED Lamp Driver IC with PFC Function Functional Description The FL7701 prefixed internal duty ratio range is below 50%, or around 400ns from timing point of view. The range is dependent on the input voltage and LED numbers in its string. Lm n V f (1 D min ) f s i rip Dmin Vin (max) (2) If the peak current is fixed at 350mApk, the formula for the peak current is: At operating mode, minimum duty is: n V f [H ] I o ( peak ) icon (1) irip 2 350 [mA] (3) In FL7701, the LED RMS current determines the inductance parameter. To drive for CCM Mode, define LED RMS current first, as: where: η is efficiency of system; VIN(max) is maximum input voltage; Vf is forward drop voltage of LED; and n is LED number in series connection. I o ( rms ) irip irip [mA] 2 (4) Substituting Equation 2 for Equation 4, the inductance of inductor is obtained. Figure 6. DCM and CCM Operation © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 7 FL7701 — Smart LED Lamp Driver IC with PFC Function In DCM Mode, inductance is: 4. Inductor Design FL7701 — Smart LED Lamp Driver IC with PFC Function Typical Performance Characteristics Π 2Π 3Π 4Π Figure 7. Typical Performance Characteristics © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 8 FL7701 — Smart LED Lamp Driver IC with PFC Function Example Application Circuits Figure 8. Application without an Electrolytic Capacitor Electrolytic Capacitor BD EMI filter LED FRD AC INPUT L HV ADIM OUT RT VCC FL7701 CS GND Figure 9. Application with an Electrolytic Capacitor © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 9 6.0 17.0 5.5 VCCHY [V] VCC [V] 16.5 16.0 15.5 15.0 5.0 4.5 14.5 14.0 -40 -20 0 20 40 60 80 100 4.0 -40 120 -20 0 Temperature [°C] 40 60 80 100 120 Temperature [°C] Figure 10. VCC vs. Temperature Figure 11. VCCHY vs. Temperature 150 14.0 140 IST [uA] VCCST+ [V] 13.5 130 13.0 120 12.5 110 12.0 -40 -20 0 20 40 60 Temperature [°C] 80 100 100 -40 120 -20 0 20 40 60 80 100 120 Temperature [°C] Figure 12. VCCST+ vs. Temperature Figure 13. IST vs. Temperature 9.0 50 48 8.5 fOSC [kHz] VCCST- [V] 20 8.0 46 44 7.5 42 7.0 -40 -20 0 20 40 60 Temperature [°C] 80 100 120 -40 Figure 14. VCCST- vs. Temperature © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 -20 0 20 40 60 Temperature [°C] 80 100 120 Figure 15. fOSC vs. Temperature (Rt=Open) www.fairchildsemi.com 10 FL7701 — Smart LED Lamp Driver IC with PFC Function Typical Characteristics 52 22 51 DMAX fOSC [kHz] 24 20 50 49 18 16 -40 -20 0 20 40 60 80 100 48 -40 120 -20 0 Temperature [°C] 20 40 60 80 100 120 Temperature [°C] Figure 17. DMAX vs. Temperature Figure 16. fOSC vs. Temperature (Rt=87kΩ) 1.7 300 280 fOSC [kHz] 1.6 VRT 260 1.5 240 1.4 220 200 -40 -20 0 20 40 60 80 100 1.3 -40 120 Temperature [°C] -20 0 20 40 60 80 100 120 Temperature [°C] Figure 19. VRT vs. Temperature Figure 18. fOSC vs. Temperature (Rt=5.95kΩ) 0.376 500 0.372 VCS1 TMIN 450 400 0.368 0.364 0.360 350 0.356 300 -40 -20 0 20 40 60 Temperature [°C] 80 100 -40 120 Figure 20. tMIN vs. Temperature © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 -20 0 20 40 60 Temperature [°C] 80 100 120 Figure 21. VCS1 vs. Temperature www.fairchildsemi.com 11 FL7701 — Smart LED Lamp Driver IC with PFC Function Typical Characteristics 15 19.5 19.0 IAD[uA] OVPVCC 14 18.5 13 12 11 10 18.0 -40 -20 0 20 40 60 80 100 9 -40 120 Temperature [°C] 0 20 40 60 80 100 120 Temperature [°C] Figure 22. OVPVCC vs. Temperature © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 -20 Figure 23. . IAD vs. Temperature www.fairchildsemi.com 12 FL7701 — Smart LED Lamp Driver IC with PFC Function Typical Characteristics 5.00 4.80 A 0.65 3.81 8 5 B 1.75 6.20 5.80 PIN ONE INDICATOR 4.00 3.80 1 5.60 4 1.27 (0.33) 1.27 0.25 C B A LAND PATTERN RECOMMENDATION SEE DETAIL A 0.25 0.10 1.75 MAX 0.25 0.19 C 0.51 0.33 0.10 C OPTION A - BEVEL EDGE 0.50 x 45° 0.25 R0.10 GAGE PLANE R0.10 OPTION B - NO BEVEL EDGE 0.36 NOTES: UNLESS OTHERWISE SPECIFIED 8° 0° 0.90 0.40 A) THIS PACKAGE CONFORMS TO JEDEC MS-012, VARIATION AA, ISSUE C, B) ALL DIMENSIONS ARE IN MILLIMETERS. C) DIMENSIONS DO NOT INCLUDE MOLD FLASH OR BURRS. D) LANDPATTERN STANDARD: SOIC127P600X175-8M. E) DRAWING FILENAME: M08AREV13 SEATING PLANE (1.04) DETAIL A SCALE: 2:1 Figure 24. 8-Lead, Small-Outline Integrated Circuit (SOIC), JEDEC MS-012, .150-Inch Narrow Body Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/. © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 13 FL7701 — Smart LED Lamp Driver IC with PFC Function Physical Dimensions FL7701 — Smart LED Lamp Driver IC with PFC Function © 2011 Fairchild Semiconductor Corporation FL7701 • Rev. 1.0.0 www.fairchildsemi.com 14