FAN6300 Highly Integrated Quasi-Resonant Current Mode PWM Controller Features Description The highly integrated FAN6300 PWM controller provides several features to enhance the performance of flyback converters. A built-in HV startup circuit can provide more startup current to reduce the startup time of the controller. Once the VDD voltage exceeds the turn-on threshold voltage, the HV startup function is disabled immediately to improve power consumption. An internal valley voltage detector ensures the power system operates at Quasi-Resonant operation in widerange line voltage and any load conditions and reduces switching loss to minimize switching voltage on drain of power MOSFET. High-Voltage Startup Quasi-Resonant Operation Cycle-by-Cycle Current Limiting Peak-Current-Mode Control Leading-Edge Blanking Internal Minimum tOFF Internal 2ms Soft-Start Over-Power Compensation GATE Output Maximum Voltage Auto-Recovery Short-Circuit Protection (FB Pin) Auto-Recovery Open-Loop Protection (FB Pin) VDD Pin & Output Voltage (DET Pin) OVP Latched FAN6300 controller also provides many protection functions. Pulse-by-pulse current limiting ensures the fixed peak current limit level, even when a short circuit occurs. Once an open-circuit failure occurs in the feedback loop, the internal protection circuit disables PWM output immediately. As long as VDD drops below the turn-off threshold voltage, controller also disables PWM output. The gate output is clamped at 18V to protect the power MOS from high gate-source voltage conditions. The minimum tOFF time limit prevents the system frequency from being too high. If the DET pin reaches OVP, internal OTP is triggered, and the power system enters latch-mode until AC power is removed. Applications To minimize standby power consumption and light-load efficiency, a proprietary green-mode function provides off-time modulation to decrease switching frequency and perform extended valley voltage switching to keep to a minimum switching voltage. AC/DC NB Adapters Open-Frame SMPS FAN6300 controller is available in both 8-pin DIP and SOP packages. Ordering Information Part Number Operating Temperature Range FAN6300DZ -40 to +105°C RoHS FAN6300SZ -40 to +105°C RoHS Eco Status Package Packing Method 8-Lead, Dual Inline Package (DIP) Tube 8-Lead, Small Outline Package (SOP) Reel & Tape For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller June 2008 FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Application Diagram Figure 1. Typical Application Internal Block Diagram HV VDD 8 6 FB 2 27V 2R Soft-Start 2ms R Timer 55ms Internal Bias OVP IHV 4.2V Latched Two Steps UVLO 16V/10V/8V FB OLP 500µs 30µs Starter CS 3 DRV Blanking Circuit S PWM Current Limit Over-Power Compensation SET 5 Q GATE 18V R IDET CLR Q Latched 0.3V tOFF-MIN (8µs/38µs) tOFF Blanking (4µs) S/H Valley Detector VDET 1st Valley tOFF-MIN +9µs VDET Latched 2.5V DET OVP DET 1 Internal OTP 0.3V 5V IDET Latched 4 7 GND NC Figure 2. Functional Block Diagram © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 2 F- Fairchild logo Z- Plant Code X- 1 digit year code Y- 1 digit week code TT: 2 digits die run code T: Package type (D=DIP, S=SOP) P: Z: Pb free, Y: Green package M: Manufacture flow code Figure 3. Marking Information © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Marking Information www.fairchildsemi.com 3 Figure 4. Pin Configuration Pin Definitions Pin # Name Description This pin is connected to an auxiliary winding of the transformer via resistors of the divider for the following purposes: - Generates a ZCD signal once the secondary-side switching current falls to zero. 1 DET - Produces an offset voltage to compensate the threshold voltage of the peak current limit to provide a constant power limit. The offset is generated in accordance with the input voltage when PWM signal is enabled. - Detects the valley voltage of the switching waveform to achieve the valley voltage switching and minimize the switching losses. A voltage comparator and a 2.5V reference voltage develop an output OVP protection. The ratio of the divider decides what output voltage to stop gate, as an optical coupler and secondary shunt regulator are used. The Feedback pin is supposed to be connected to the output of the error amplifier for achieving the voltage control loop. The FB should be connected to the output of the optical coupler if the error-amplifier is equipped at the secondary-side of the power converter. 2 FB For the primary-side control application, this pin is applied to connect a RC network to the ground for feedback-loop compensation. FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Pin Configuration The input impedance of this pin is a 5kΩ equivalent resistance. A 1/3 attenuator connected between the FB and the PWM circuit is used for the loop gain attenuation. FAN6300 performs an open-loop protection once the FB voltage is higher than a threshold voltage (around 4.2V) more than 55ms. Input to the comparator of the over-current protection. A resistor senses the switching current and the resulting voltage is applied to this pin for the cycle-by-cycle current limit. The threshold voltage for peak current limit is 0.8V. 3 CS 4 GND The power ground and signal ground. A 0.1µF decoupling capacitor placed between VDD and GND is recommended. 5 GATE Totem-pole output generates the PWM signal to drive the external power MOSFET. The clamped gate output voltage is 18V. 6 VDD 7 NC No connect. 8 HV High-voltage startup. Power supply. The threshold voltages for startup and turn-off are 16V and 10V. The startup current is less than 20µA and the operating current is lower than 4.5mA. © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 4 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 VDD Parameter Min. DC Supply Voltage Max. Unit 30 V VHV HV Pin 500 V VH GATE Pin -0.3 25.0 V VL VFB, VCS, VDET -0.3 7.0 V PD Power Dissipation SOP-8 400 mW DIP-8 800 mW TJ Operating Junction Temperature +150 °C +150 °C TSTG TL ESD Storage Temperature Range -55 +270 °C ESD Capability, Human Body Model Lead Temperature, Soldering 10 Seconds 2.0 KV ESD Capability, Machine Model 200 V Notes: 1. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. 2. All voltage values, except differential voltages, are given with respect to GND pin. Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol TA Parameter Operating Ambient Temperature © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 Min. Max. Unit -40 +105 °C FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Absolute Maximum Ratings www.fairchildsemi.com 5 VDD=15V, TA=25℃, unless otherwise specified. Symbol Parameter Conditions Min. Typ. Max. Units 25 V VDD SECTION VOP Continuously Operating Voltage VDD-ON Turn-on Threshold Voltage 16 VDD-PWM-OFF PWM Off Threshold Voltage 10 V VDD-OFF Turn-Off Threshold Voltage 8 V IDD-ST Startup Current 0V< VDD < VDD-ON GATE Open IDD-OP Operating Current VDD=15V, fs=60KHz, CL=2nF Operating Current at PWM-Off Phase VDD=VDD-PWM-OFF-0.5V IDD-PWM-OFF 4.5 V 30 µA 5.5 mA 80 µA VDD-OVP VDD Over-Voltage Protection (Latch-Off) 27 V tVDD-OVP VDD OVP Debounce Time 150 µs 1.2 mA HV START-UP CURRENT SOURCE SECTION IHV IHV-LC Supply Current Drawn From HV Pin VAC=90V (VDC=120V), VDD=0V Leakage Current After Startup HV=500V, VDD=VDD-OFF +1V 1 20 µA 1/3.00 1/3.25 V/V FEEDBACK INPUT SECTION AV Input-voltage to Current Sense Attenuation ZFB Input Impedance IOZ Bias Current VOZ Zero Duty Cycle Input Voltage VFB-OLP Open-Loop Protection Threshold Voltage tD-OLP Debounce Time for Open-Loop / Overload Protection tSS AV=ΔVCS/ΔVFB 0<VCS<0.9 1/2.75 3 FB=VOZ 5 7 KΩ 1.2 2.0 mA 1 3.9 4.2 V 4.5 V 55 Internal Soft-Start Time ms 1.6 2.0 2.4 ms Comparator Reference Voltage 2.45 2.50 2.55 V VV-HIGH Output High Voltage 4.5 VV-LOW Output Low Voltage tDET-OVP Output OVP (Latched) Debounce Time FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Electrical Characteristics DET PIN OVP AND VALLEY DETECTION SECTION VDET-OVP IDET-SOURCE 100 V 150 Maximum Source Current VDET-HIGH Upper Clamp Voltage VDET-LOW Lower Clamp Voltage tOFF-BNK Leading-Edge Blanking Time for DET(3) OVP, PWM MOS Turns Off 0.5 V 200 µs 1 mA 5 0.1 V 0.3 V 4 µs Note: 3. Guaranteed by design. © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 6 VDD=15V, TA=25℃, unless otherwise specified. Symbol Parameter Conditions Min. Typ. Max. Units 40 45 50 µs OSCILLATOR SECTION tON-MAX Maximum On Time tOFF-MIN Minimum Off Time (Maximum Frequency) VFB≧VN 8 µs VFB=VG 38 µs VN Beginning of Green-On Mode at FB Voltage Level 2.1 V VG Beginning of Green-Off Mode at FB Voltage Level 1.2 V Green-Off Mode VFB Hysteresis Voltage 0.1 V VFB<VG 500 µs VFB>VFB-OLP 30 µs 9 µs ΔVFBG tSTARTER Start Timer (Time-out Timer) tTIME-OUT Timeout After tOFF-MIN (If No Valley Signal) OUTPUT SECTION VOL Output Voltage Low VDD=15V, IO=150mA VOH Output Voltage High VDD=12V, IO=150mA 1.5 7.5 V V tR Rising Time 120 ns tF Falling Time 60 ns VCLAMP GATE Output Clamping Voltage 17 18 19 V 150 250 ns 0.80 0.85 V CURRENT SENSE SECTION tPD Delay to Output VLIMIT Cycle-by-cycle Current Limit Threshold Voltage VSLOPE Slope Compensation tBNK 0.75 tON=45µs 0.3 V tON=0µs 0.1 V Leading Edge Blanking Time (MOS Turns On) 225 VCS-H VCS Camped High Voltage CS Pin Floating 4.5 tCS-H Delay Time CS Pin Floating 100 © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 300 150 375 ns 5.0 V 200 µs FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Electrical Characteristics (Continued) www.fairchildsemi.com 7 These characteristic graphs are normalized at TA = 25°C. 17.0 10.5 10.3 V DD-P WM-OFF (V) V DD-ON (V) 16.5 16.0 15.5 10.1 9.9 9.7 15.0 9.5 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 50 65 80 95 110 125 Figure 6. PWM Off Threshold Voltage 8.2 10 8.1 9 8.0 8 7.9 7.8 7 6 5 7.6 4 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 Temperature℃ Temperature℃ Figure 7. Turn-off Threshold Voltage Figure 8. Startup Current 5.2 2.2 5.0 2.0 4.8 1.8 IHV (mA) IDD-OP (mA) 35 Figure 5. Turn-on Threshold Voltage 7.7 4.6 4.4 4.2 110 125 110 125 1.6 1.4 1.2 4.0 1.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 Temperature℃ Temperature℃ Figure 9. Operating Current Figure 10. Supply Current Drawn From HV Pin 0.30 1.0 V DE T-LOW (V) 0.8 IHV-LC (uA) 20 Temperature℃ IDD-S T (uA) V DD-OFF (V) Temperature℃ FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Typical Performance Characteristics 0.6 0.4 0.25 0.20 0.15 0.2 0.0 0.10 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 Temperature℃ -10 5 20 35 50 65 80 95 110 125 Temperature℃ Figure 11. Leakage Current After Startup © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 -25 Figure 12. Lower Clamp Voltage www.fairchildsemi.com 8 2.6 9.0 2.6 8.5 tOFF-MIN (us) V DE T-OVP (V) These characteristic graphs are normalized at TA = 25°C. 2.5 2.5 8.0 7.5 2.4 7.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 Temperature℃ Temperature℃ Figure 13. Comparator Reference Voltage Figure 14. Minimum Off Time (VFB>VN) 600 40 575 tS TAR TE R (us) tOFF-MIN (us) 39 38 37 36 550 525 500 475 35 450 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 -25 -10 5 20 35 50 65 80 95 110 Temperature℃ Temperature℃ Figure 15. Minimum Off Time (VFB=VG) Figure 16. Start Timer (VFB<VG) © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 125 FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Typical Performance Characteristics www.fairchildsemi.com 9 The FAN6300 of PWM controller integrates designs to enhance the performance of flyback converters. An internal valley voltage detector ensures power system operates at Quasi-Resonant (QR) operation in a wide range of line voltage. The following descriptions highlight some of the features of the FAN6300 series. Startup Current For startup, the HV pin is connected to the line input or bulk capacitor through an external diode and resistor, RHV, which are recommended as 1N4007 and 100kΩ. Typical startup current drawn from pin HV is 1.2mA and it charges the hold-up capacitor through the diode and resistor. When the VDD voltage level reaches VDD-ON, the startup current switches off. At this moment, the VDD capacitor only supplies the FAN6300 to maintain VDD until the auxiliary winding of the main transformer provides the operating current. Green-mode Operation The proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load conditions. VFB, which is derived from the voltage feedback loop, is taken as the reference. In Figure 19, once VFB is lower than VN, the tOFF-MIN time increases linearly with lower VFB. The valley voltage detection signal does not start until the tOFF-MIN time finishes. Therefore, the valley detect circuit is activated until the tOFF-MIN time finishes, which decreases the switching frequency and provides extended valley voltage switching. However, in very light load condition, it might fail to detect the valley voltage after the tOFF-MIN expires. Under this condition, an internal tTIME-OUT signal initiates a new cycle start after a 9μs delay. Figure 20 and Figure 21 show the two different conditions. Valley Detection The DET pin is connected to an auxiliary winding of the transformer via resistors of the divider to generate a valley signal once the secondary-side switching current discharges to zero. It detects the valley voltage of the switching waveform to achieve the valley voltage switching. This ensures QR operation, minimizes switching losses, and reduces EMI. Figure 17 shows divider resistors RDET and RA. RDET is recommended as 150kΩ to 220kΩ to achieve valley voltage switching. When VAUX (in Figure 17) is negative, the DET pin voltage is clamped to 0.3V. Figure 19. VFB vs. tOFF-MIN Curve FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Operation Description Figure 17. Valley Detect Section The internal timer (minimum tOFF time) prevents gate retriggering within 8µs after the gate signal going-low transition. The minimum tOFF time limit prevents the system frequency being too high. Figure 18 shows a typical drain voltage waveform with first valley switching. Figure 18. First Valley Switching © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 Figure 20. QR Operation in Extended Valley Voltage Detection Mode Figure 21. Internal tTIME-OUT Initiates New Cycle After Failure to Detect Valley Voltage (with 9µs Delay) www.fairchildsemi.com 10 VDD Over-Voltage Protection Peak-current-mode control is utilized to regulate output voltage and provide pulse-by-pulse current limiting. The switch current is detected by a sense resistor into the CS pin. The PWM duty cycle is determined by this current sense signal and VFB. When the voltage on CS pin reaches around VLIMIT = (VFB-1.2)/3, the switch cycle is terminated immediately. VLIMIT is internally clamped to a variable voltage around 0.8V for output power limit. VDD over-voltage protection prevents damage due to abnormal conditions. Once the VDD voltage is over the VDD over-voltage protection voltage (VDD-OVP) and lasts for tVDDOVP, the PWM pulse is disabled until the VDD voltage drops below the UVLO, then starts again. Leading Edge Blanking (LEB) Each time the power MOFFET switches on, a turn-on spike occurs on the sense resistor. To avoid premature termination of the switching pulse, lead-edge blanking time is built in. During the blanking period, the current limit comparator is disabled; it cannot switch off the gate driver. Under-Voltage Lockout (UVLO) Output Over-Voltage Protection The output over-voltage protection works by the sampling voltage, as shown in Figure 23, after switch-off sequence. A 4μs blanking time ignores the leakage inductance ringing. A voltage comparator and a 2.5V reference voltage develop an output OVP protection. The ratio of the divider determines the sampling voltage of the stop gate, as an optical coupler and secondary shunt regulator are used. If the DET pin OVP is triggered, power system enters latch-mode until AC power is removed. The turn-on, PWM-off, and turn-off thresholds are fixed internally at 16/10/8V. During startup, the startup capacitor must be charged to 16V through the startup resistor to enable the IC. The hold-up capacitor continues to supply VDD until energy can be delivered from the auxiliary winding of the main transformer. VDD must not drop below 10V during this startup process. This UVLO hysteresis window ensures that hold-up capacitor is adequate to supply VDD during startup. Gate Output The BiCMOS output stage is a fast totem-pole gate driver. Cross conduction has been avoided to minimize heat dissipation, increase efficiency, and enhance reliability. The output driver is clamped by an internal 18V Zener diode to protect power MOSFET transistors against undesired over-voltage gate signals. Over-Power Compensation To compensate this variation for wide AC input range, the DET pin produces an offset voltage to compensate the threshold voltage of the peak current limit to provide a constant-power limit. The offset is generated in accordance with the input voltage when PWM signal is enabled. This results in a lower current limit at high-line inputs than low-line inputs. At fixed-load condition, the CS limit is higher when the value of RDET is higher. RDET also affects the H/L line constant power limit. Figure 23. Voltage Sampled After 4μs Blanking Time After Switch-off Sequence Short-Circuit and Open-Loop Protection The FB voltage increases every time the output of the power supply is shorted or overloaded. If the FB voltage remains higher than a built-in threshold for longer than tD-OLP, PWM output is turned off. As PWM output is turned-off, the supply voltage VDD begins decreasing. FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Current Sensing and PWM Current Limiting When VDD goes below the PWM-off threshold of 10V, VDD decreases to 8V, then the controller is totally shut down. VDD is charged up to the turn-on threshold voltage of 16V through the startup resistor until PWM output is restarted. This protection feature continues as long as the overloading condition persists. This prevents the power supply from overheating due to overloading. Figure 22. H/L Line Constant Power Limit Compensated by DET Pin © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 11 8 C 5 H E F 1 4 b e D Θ A1 L A Figure 24. 8-Lead, Small Outline Package (SOP) Dimensions Symbol Millimeter Min. A 1.346 A1 0.101 Typ. Inch Max. Min. 1.752 0.053 0.254 0.004 Typ. 0.069 0.010 b 0.406 0.016 c 0.203 0.008 D 4.648 E 3.810 e 1.016 4.978 1.270 0.183 3.987 0.150 1.524 0.040 0.196 0.157 0.050 0.060 0.015X45° 0.381X45° F Max. H 5.791 6.197 0.228 0.244 L 0.406 1.270 0.016 0.050 θ˚ 0° FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Physical Dimensions 8° 0° 8° 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/. © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 12 D Θ¢X 5 E1 8 B A A2 4 A1 1 e E L b1 b e Figure 25. 8-Lead, Dual Inline Package (DIP) Dimensions Symbol Millimeter Min. Typ. A 0.381 A2 3.175 b Min. Typ. 0.015 3.302 3.429 0.125 E 9.271 6.223 6.350 0.135 0.018 10.160 0.355 7.620 e 0.130 0.060 0.457 9.017 Max. 0.210 1.524 b1 E1 Max. 5.334 A1 D Inch 0.365 0.400 0.300 6.477 0.245 2.540 0.250 0.255 0.100 L 2.921 3.302 3.810 0.115 0.130 0.150 eB 8.509 9.017 9.525 0.335 0.355 0.375 θ° 0° 7° FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller Physical Dimensions (Continued) 15° 0° 7° 15° 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/. © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 13 FAN6300 — Highly Integrated Quasi-Resonant Current Mode PWM Controller © 2007 Fairchild Semiconductor Corporation FAN6300 • Rev. 1.0.1 www.fairchildsemi.com 14