DATASHEET SEARCH SITE | WWW.ALLDATASHEET.COM
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 11
Technical content
Features
Boundary Mode PFC Controller Low Input Current THD Controlled On-Time PWM Zero-Current Detection Cycle-by-Cycle Current Limiting Leading-Edge Blanking Instead of RC Filtering Low Startup Current: 10µA Typical Low Operating Current: 4.5mA Typical Feedback Open-Loop Protection Programmable Maximum On-Time (MOT) Output Over-Voltage Clamping Protection Clamped Gate Output Voltage: 16.5V
Applications
General LED Lighting Industrial, Commercial and Residential Fixtures Outdoor Lighting: Street, Roadway, Parking, Construction, and Ornamental LED Lighting
Description
The FL6961 is a general lighting power controller for low- to high-power lumens applications requiring power factor correction. It is designed for flyback or boost converter operating in Boundary Mode. The FL6961 provides a controlled on-time to regulate the output DC voltage and achieves natural power factor correction (PFC). The maximum on-time of the external switch is programmable to ensure safe operation during AC brownouts. An innovative multi-vector error amplifier provides rapid transient response and precise output voltage clamping. A built-in circuit disables the controller if the output feedback loop is opened. The startup current is lower than 20µA a nd the operating current is less than 6mA. The supply voltage can be up to 25V, maximizing application flexibility.
Ordering Information
Part Number Operating Temperature Range Package Packing Method FL6961MY -40°C to +125°C 8-Pin, Small Outline Package (SOP) Tape & Reel
Figure 4. Marking Information Figure 5. Pin Configuration (Top View) divider. This pin is also used for over-voltage clamping and open-loop feedback protection. between this pin and GND is suggested.
3 MOT
5 ZCD
started. If it is connected to GND, the device is disabled. 8 V CC Power Supply. Driver and control circuit supply voltage.
© 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FL6961 • Rev. 1.0.2 4 FL6961 — Single-Stage Flyback and Boundary Mode PFC Controller for Lighting Absolute Maximum Ratings Stresses exceeding the absolute maximum ratings may dam age the device. The device may not function or be operable above the recommended operating conditions and stressi ng 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. All volt age values, except differential voltage, are given with respect to GND pin. Symbol Parameter Min. Max. Unit VVCC DC Supply Voltage 30 V VHIGH Gate Driver -0.3 30.0 V VLOW Others (INV, COMP, MOT, CS) -0.3 7.0 V VZCD Input Voltage to ZCD Pin -0.3 12.0 V PD Power Dissipation 660 mW TJ Operating Junction Temperature -40 +150 C θJA Thermal Resistance (Junction-to-Air) 150 C/W θJC Thermal Resistance (Junction-to-Case) 39 C/W TSTG Storage Temperature Range -65 + 150 C TL Lead Temperature (Wave Soldering or IR, 10 Seconds) +230 C ESD Human Body Model: JESD22-A114 2.5 KV Machine Model: JESD22-A115 200 V Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ens ure optimal performance to the datasheet specificatio ns. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol Parameter Min. Typ. Max. Unit TA Operating Ambient Te mperature -40 +125 C
© 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FL6961 • Rev. 1.0.2 5 FL6961 — Single-Stage Flyback and Boundary Mode PFC Controller for Lighting
Electrical Characteristics
Unless otherwise noted, VCC=15V and TJ=-40°C to 150°C. Current is defined as positive into the device and negative out of the device. Symbol Parameter Conditions Min. Typ. Max. Units VCC Section VCC-OP Continuous Operation Voltage 24.5 V VCC-ON Turn-On Threshold Voltage 11.5 12.5 13.5 V VCC-OFF Turn-Off Threshold Vo ltage 8.5 9.5 10.5 V ICC-ST Startup Current V CC=VCC-ON – 0.16V 10 20 µA ICC-OP Operating Supply Current VCC=12V, VCS=0V, CL=3nF, fSW=60KHz 4.5 6 mA VCC-OVP V DD Over-Voltage Protection Level 26.8 27.8 28.8 V tD-VCCOVP V DD Over-Voltage Protection Debounce 30 µs Error Amplifier Section VREF Reference Voltage 2.475 2.500 2.525 V Gm Transconductance 125 μmho VINVH Clamp High Feedback Voltage 2.65 2.70 V VINVL Clamp Low Feedback Voltage 2.25 2.30 V VOUT HIGH Output High Voltage 4.8 V VOZ Zero Duty Cycl e Output Voltage 1.15 1.25 1.35 V VINV-OVP Over-Voltage Protection for INV Input 2.70 2.75 2.80 V VINV-UVP Under-Voltage Protection for INV Input 0.40 0.45 0.50 V ICOMP Source Current VINV=2.35V, VCOMP=1.5V 10 20 μA VINV=1.5V 550 800 Sink Current V INV=2.65V, VCOMP=5V 10 20 Current-Sense Section VPK Threshold Voltage for Peak Current Limit Cycle-by-Cycle Limit 0.77 0.82 0.87 V tPD Propagation Delay 200 ns tLEB Leading-Edge Blanking Time RMOT=24kΩ, VCOMP=5V 400 500 ns RMOT=24kΩ, VCOMP=VOZ+50mV 270 350 Gate Section VZ-OUT Output Voltage Maximum (Clamp) V CC=25V 14.5 16.0 17.5 V VOL Output Voltage Low V CC=15V, IO=100mA 1.4 V VOH Output Voltage High V CC=14V, IO=100mA 8 V tR Rising Time VCC=12V, CL=3nF, 20~80% 80 ns tF Falling Time VCC=12V, CL=3nF, 80~20% 40 ns Continued on the following page…
© 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FL6961 • Rev. 1.0.2 6 FL6961 — Single-Stage Flyback and Boundary Mode PFC Controller for Lighting Unless otherwise noted, VCC=15V and TJ=-40°C to 150°C. Current is defined as positive into the device and negative out of the device. Symbol Parameter Conditions Min. Typ. Max. Units Zero-Current Detection Section VZCD Input Threshold Voltage Rising Edge V ZCD Increasing 1.9 2.1 2.3 V HYS of VZCD Threshold Voltage Hysteresis V ZCD Decreasing 0.35 V VZCD-HIGH Upper Clamp Voltage I ZCD=3mA 12 V VZCD-LOW Lower Clamp Voltage I ZCD=-1.5mA 0.3 V tDEAD Maximum Delay, ZCD to Output Turn-On VCOMP=5V, fSW=60KHz 100 400 ns tRESTART Restart Time Output Turned Off by ZCD 300 500 700 μs tINHIB Inhibit Time (Maximum Switching Frequency Limit) RMOT=24kΩ 2.8 μs VDIS Disable Threshold Voltage 130 200 250 mV tZCD-DIS Disable Function Debounce Time RMOT=24kΩ, VZCD=100mV 800 μs Maximum On Time Section VMOT Maximum On Time Voltage 1.25 1.30 1.35 V tON-MAX Maximum On Time Programming (Resistor Based) RMOT=24kΩ, VCS=0V, VCOMP=5V 25 μs
© 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FL6961 • Rev. 1.0.2 9 FL6961 — Single-Stage Flyback and Boundary Mode PFC Controller for Lighting Functional Description Error Amplifier The inverting input of the error amplifier is referenced to INV. The output of the error amplifier is referenced to COMP. The non-inverting input is internally connected to a fixed 2.5V ±2% voltag e. The output of the error amplifier is used to determi ne the on-time of the PWM output and regulate the output voltage. To achieve a low input current THD, the variation of the on-time within one input AC cycle should be very small. A multi- vector error amplifier is built in to provide fast transient response and precise output voltage clamping. Connecting a capacitance, such as 1µF, between COMP and GND is suggested. The error amplifier is a trans-conductance amplifier t hat converts voltage to current with a 125µmho. Startup Current Typical startup current is less than 20µA. This ultra-low startup current allows the usage of a high resistance, low-wattage startup resistor. For example, 1M Ω/0.25W startup resistor and a 10µF/25V (V CC hold-up) capacitor are recommended for an AC-to-DC power adaptor with a wide input range 85-265VAC. Operating Current Operating current is typicall y 4.5mA. The low operating current enables better efficiency and reduces the requirement of VCC hold-up capacitance. Maximum On-Time Operation Given a fixed inductor value and maximum output power, the relationship between on-time and line voltage is: 2 rms o on V PLt (1) If the line voltage is too low or the inductor value is too high, t ON is too long. To avoid extra low operating frequency and achieve brownout protection, the maximum value of tON is programmable by one resistor, RI, connected between MOT and GND. A 24k Ω resistor RI generates corresponds to 25µs maximum on time: skRt Ion 24 25)((max) (2) The range of the maximum on-time is 10 ~ 50µs. Peak Current Limiting The switch current is sensed by one resistor. The signal is fed into the CS pin and an input terminal of a comparator. A high voltage on the CS pin terminates the switching cycle immediately and cycle-by-cycle current limit is achieved. T he designed threshold of the protection point is 0.82V. Leading-Edge Blanking (LEB) A turn-on spike on the CS pin appears when the power MOSFET is switched on. At the beginning of each switching pulse, the current-limit comparator is disabled for around 400ns to avoid premature termination. The gate drive output cannot be switched off during the blanking period. Conventional RC filtering is not necessary, so the propagati on delay of current limit protection can be minimized. Under-Voltage Lockout (UVLO) The turn-on and turn-off threshold voltages are fixed internally at 12V and 9.5V, respectively. This hysteresis behavior guarantees a one-s hot startup with proper startup resistor and hold-up c apacitor. With an ultra-low startup current of 20µA, one 1M Ω R IN is sufficient for startup under low input line voltage, 85V rms. Power dissipation on RIN would be less than 0.1W even under high line (VAC=265Vrms) condition. Output Driver With low on resistance and high current driving capability, the output driver can drive an external capacitive load larger than 3000pF. Cross conduction current has been avoided to minimize heat dissipation, improving efficiency and reliabilit y. This output driver is internally clamped by a 16.5V Zener diode. Zero-Current Detection (ZCD) The zero-current detection of the inductor is achieved using its auxiliary winding. When the stored energy of the inductor is fully releas ed to output, the voltage on ZCD goes down and a new switching cycle is enabled after a ZCD trigger. The power MOSFET is always turned on with zero inductor current such that turn-on loss and noise can be minimized. The converter works in Boundary Mode and peak inductor current is always exactly twice of the average current. A natural power factor correction function is achieved with the low- bandwidth, on-time modulation. An inherent maximum off time is built in to ensure proper startup operation. This ZCD pin can be used as a synchronous input. Noise Immunity Noise on the current sense or control signal can cause significant pulse-width jitter, particularly in Boundary Mode. Slope compensation and a built-in debounce circuit can alleviate this problem. Because the FL6961 has a single ground pin, high sink current at the output cannot be returned separately. Good high-frequency or RF layout practices should be followed. Avoiding long PCB traces and component leads, locating compensation and filter components near to the FL6961, and increasing the power MOSFET gate resistance all improve performance.
B) ALL DIMENSIONS ARE IN MILLIMETERS. D) LANDPATTERN STANDARD: SOIC127P600X175-8M.
1.75 MAX
Figure 15. 8-Lead, SOIC, JEDEC MS-012, .150 Inch Narrow Body specifically the warranty therein, which covers Fairchild products. http://www.fairchildsemi.com/packaging/.
© 2010 Fairchild Semiconductor Corporation www.fairchildsemi.com FL6961 • Rev. 1.0.2 11 FL6961 — Single-Stage Flyback and Boundary Mode PFC Controller for Lighting