FAN7529N

FAN7529 Critical Conduction Mode PFC Controller Features Description „ Low Total Harmonic Distortion (THD) The FAN7529 is an active power factor correction (PFC) controller for boost PFC applications that operates in critical conduction mode (CRM). It uses the voltage mode PWM that compares an internal ramp signal with the error amplifier output to generate MOSFET turn-off signal. Because the voltage-mode CRM PFC controller does not need rectified AC line voltage information, it saves the power loss of the input voltage sensing network necessary for the current-mode CRM PFC controller. „ Precise Adjustable Output Over-Voltage Protection „ Open-Feedback Protection and Disable Function „ Zero Current Detector „ 150µs Internal Start-up Timer „ MOSFET Over-Current Protection „ Under-Voltage Lockout with 3.5V Hysteresis „ Low Start-up (40µA) and Operating Current (1.5mA) „ Totem Pole Output with High State Clamp FAN7529 provides many protection functions, such as over-voltage protection, open-feedback protection, overcurrent protection, and under-voltage lockout protection. The FAN7529 can be disabled if the INV pin voltage is lower than 0.45V and the operating current decreases to 65µA. Using a new variable on-time control method, THD is lower than the conventional CRM boost PFC ICs. „ +500/-800mA Peak Gate Drive Current „ 8-Pin DIP or 8-Pin SOP Applications „ Adapter „ Ballast „ LCD TV, CRT TV „ SMPS Related Application Notes „ AN-6026 - Design of Power Factor Correction Circuit Using FAN7529 Ordering Information Part Number Operating Temp. Range Pb-Free Package Packing Method Marking Code FAN7529N -40°C to +125°C Yes 8-DIP Rail FAN7529 FAN7529M -40°C to +125°C Yes 8-SOP Rail FAN7529 FAN7529MX -40°C to +125°C Yes 8-SOP Tape & Reel FAN7529 © 2006 Fairchild Semiconductor Corporation FAN7529 Rev. 1.0.2 www.fairchildsemi.com FAN7529 Critical Conduction Mode PFC Controller April 2007 FAN7529 Critical Conduction Mode PFC Controller Typical Application Diagrams L VO D AC IN NAUX VAUX RZCD R2 ZCD CO VCC FAN7529 INV MOT CS COMP R1 GND FAN7529 Rev. 00 Figure 1. Typical Boost PFC Application Internal Block Diagram 2.5V Ref VCC 8 UVLO 12V 8.5V Vref1 VCC Internal Bias Drive Output Disable 7 OUT Timer ZCD 5 S 6.7V Q 1.4V 1.5V R Zero Current Detector CS OVP 4 Disable 40k 8pF 0.8V Ramp Signal Saw Tooth MOT 3 Generator 2.9V 2.675V 2.5V 0.45V 0.35V Current Protection Comparator Vref1 1V Offset Error Amplifier Gm 1V~5V Range 1 INV 2 6 GND COMP FAN7529 Rev. 00 Figure 2. Functional Block Diagram of FAN7529 © 2006 Fairchild Semiconductor Corporation FAN7529 Rev. 1.0.2 www.fairchildsemi.com 2 VCC OUT GND ZCD 8 7 6 5 YWW FAN7529 1 2 3 4 INV COMP MOT CS FAN7529 Rev. 00 Figure 3. Pin Configuration (Top View) Pin Definitions Pin # Name Description 1 INV This pin is the inverting input of the error amplifier. The output voltage of the boost PFC converter should be resistively divided to 2.5V. 2 COMP This pin is the output of the transconductance error amplifier. Components for output voltage compensation should be connected between this pin and GND. 3 MOT This pin is used to set the slope of the internal ramp. The voltage of this pin is maintained at 2.9V. If a resistor is connected between this pin and GND, current flows out of the pin and the slope of the internal ramp is proportional to this current. 4 CS This pin is the input of the over-current protection comparator. The MOSFET current is sensed using a sensing resistor and the resulting voltage is applied to this pin. An internal RC filter is included to filter switching noise. 5 ZCD This pin is the input of the zero current detection block. If the voltage of this pin goes higher than 1.5V, then goes lower than 1.4V, the MOSFET is turned on. 6 GND This pin is used for the ground potential of all the pins. For proper operation, the signal ground and the power ground should be separated. 7 OUT This pin is the gate drive output. The peak sourcing and sinking current levels are +500mA and -800mA respectively. For proper operation, the stray inductance in the gate driving path must be minimized. 8 VCC This pin is the IC supply pin. IC current and MOSFET drive current are supplied using this pin. © 2006 Fairchild Semiconductor Corporation FAN7529 Rev. 1.0.2 www.fairchildsemi.com 3 FAN7529 Critical Conduction Mode PFC Controller Pin Assignments 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. TA = 25°C unless otherwise specified. Symbol VCC IOH, IOL Iclamp Parameter Supply Voltage Peak Drive Output Current Driver Output Clamping Diodes VO>VCC or VO90% at 85VAC input) „ Low Total Harmonic Distortion (THD) (