FAN6791

FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller April 2009 FAN6791 / FAN6793 Highly Integrated, Dual-PWM Combination Controller Features High-Voltage Startup Low Operating Current Interleaved Stand-by PWM / Forward PWM Switching Green Mode Stand-by PWM / Forward PWM Linearly Decreasing Stand-by PWM Frequency to 20kHz Remote On / Off AC Brownout Protection Forward PWM with Soft-Start Frequency Hopping to Reduce EMI Emissions Cycle-by-Cycle Current Limiting for Stand-by PWM / Forward PWM Leading-Edge Blanking for Stand-by PWM / Forward PWM Synchronized Slope Compensation for Stand-by PWM / Forward PWM GATE Output Maximum Voltage Clamp VDD Over-Voltage Protection (OVP) VDD Under-Voltage Lockout (UVLO) Internal Open-Loop Protection for Stand-by PWM / Forward PWM Constant Power Limit for Stand-by PWM / Forward PWM Description The highly integrated FAN6791/3 dual PWM combination controller provides several features to enhance the performance of converters. To minimize standby power consumption, a proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency at light-load conditions. To avoid acoustic-noise problems, the minimum PWM frequency is set above 20KHz. This green-mode function enables the power supply to meet international power conservation requirements. With the internal high-voltage startup circuitry, the power loss due to bleeding resistors is also eliminated. To further reduce power consumption, FAN6791/3 is manufactured using the CMOS process, which allows an operating current of only 6mA. FAN6791/3 integrates a frequency-jittering function internally to reduce EMI emissions of a power supply with minimum line filters. The built-in synchronized slope compensation achieves stable peak-current-mode control. The proprietary internal line compensation ensures constant output power limit. FAN6791/3 provides many protection functions, including brownout protection, cycle-by-cycle current limiting, and an internal open-loop protection circuit to ensure safety should an open-loop or output shortcircuit failure occur. PWM output is disabled until VDD drops below the UVLO lower limit when the controller restarts. As long as VDD exceeds ~24.5V, the internal OVP circuit is triggered. Applications General-purpose switch-mode power supplies and flyback power converters, including: PC-ATX Power Supplies © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com FAN6791 / FAN6793 —Highly Integrated, Dual-PWM Combination Controller Ordering Information Part Number FAN6791NY FAN6793NY FAN6791MY FAN6793MY OPWM Operating Maximum Duty Temperature Range 48% 65% 48% 65% -40°C to +105°C -40°C to +105°C -40°C to +105°C -40°C to +105°C Eco Status Green Green Green Green Package 16-pin Dual In-Line Package (DIP) 16-pin Dual In-Line Package (DIP)) 16-pin Small Out-Line Package (SOP) 16-pin Small Out-Line Package (SOP) Packing Method Tube Tube Tape & Reel Tape & Reel For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. Application Diagram Figure 1. Typical Application © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com 2 FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller Block Diagram Pattern Generator Figure 2. Function Block Diagram © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com 3 FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller Marking Information F – Fairchild Logo Z – Plant Code X – 1-Digit Year Code Y – 1-Digit Week Code TT – 2-Digit Die Run Code T – Package Type (N:DIP, M:SOP) P – Y: Green Package M – Manufacture Flow Code Figure 3. Top Mark Pin Configuration Figure 4. Pin Configuration (Top View) © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com 4 FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller Pin Definitions Pin # 1 2 3 Name HV NC GND Description For startup, this pin is pulled HIGH to the line input or bulk capacitor via resistors. No connection. Ground. Oscillator Setting. One resistor connected between RI and ground pins determines the switching frequency (resistance between 12 ~ 47kΩ is recommended). The switching frequency is equal to [1560 / RI]kHz, where RI is in kΩ. For example, if RI is equal to 24kΩ, then the switching frequency is 65kHz. Voltage Feedback for Flyback PWM Stage. It is internally pulled HIGH through a 6.5kΩ resistor. An external opto-coupler from secondary feedback circuit is usually connected to this pin. PWM Current Sense for Flyback PWM Stage. The sensed voltage is used for peak-currentmode control and cycle-by-cycle current limiting. Voltage Feedback for Forward PWM Stage. It is internally pulled HIGH through a 6.5kΩ resistor. An external opto-coupler from secondary feedback circuit is usually connected to this pin. PWM Current Sense for Forward PWM Stage. Via a current sense resistor, this pin provides the control input for peak-current-mode control and cycle-by-cycle current limiting. Reference voltage. This pin can provide a reference voltage 5V. PWM Soft-Start. During startup, the SS pin charges an external capacitor with a 20µA constant current source. The voltage on FBPWM is clamped by SS during startup. In the event of a protection condition occurring and/or forward PWM being disabled, the SS pin quickly discharges. PWM Remote ON/OFF. Active HIGH. The forward PWM is disabled whenever the voltage at this pin is lower than 0.8V or the pin is open. Ground. The power ground. Forward PWM Gate Drive. The totem-pole output drive for the forward PWM MOSFET. This pin is internally clamped under 16V to protect the MOSFET. Power Supply. The internal protection circuit disables PWM output as long as VDD exceeds the OVP trigger point. Flyback PWM Gate Drive. The totem-pole output drive for the forward PWM MOSFET. This pin is internally clamped under 16V to protect the MOSFET. Line-Voltage Detection. The pin is used for line compensation, for forward, and brownout protection. 4 RI 5 6 7 8 9 10 11 12 13 14 15 16 FBFYB IFYB FBPWM IPWM VREF SS ON/OFF PGND OPWM VDD OFYB VRMS © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com 5 FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller Absolute Maximum Ratings 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. All voltage values, except differential voltage, are given with respect to GND pin. Stresses beyond those listed under “absolute maximum ratings “may cause permanent damage to the device. Symbol VDD VHV VHIGH VLOW PD TJ TSTG RΘ j-a TL DC Supply Voltage Parameter Input Voltage to HV Pin OPWM, OFYB, ON/OFF Others Power Dissipation (TA < 50°C) Operating Junction Temperature Storage Temperature Range Thermal Resistance (Junction-to-Case) Lead Temperature (Wave Soldering, 10 Seconds) Human Body Model , JEDEC:JESD22-A114 (All Pins Except HV Pin) Charged Device Model , JEDEC:JESD22-C101 (All Pins Except HV Pin) Min. Max. 27 500 Unit V V V V °C/W °C °C °C/W °C -0.3 -0.3 -40 -55 27.0 7.0 800 +125 +150 82.5 +260 3.5 ESD kV 1.5 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 Min. -40 Max. +105 Unit °C © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com 6 FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller Electrical Characteristics VDD=18V; RI=24kΩ;TA =25°C, unless noted. Symbol VDD Section VDD-OP IDD ST IDD-OP1 IDD-OP2 VTH-ON VTH-OFF VTH-OLP ITH-OLP VDD-OVP tOVP HV ID IHV-CS VRI fOSC Parameter Continuously Operating Voltage Startup Current Operating Current 1 Operating Current 2 Start Threshold Voltage Minimum Operating Voltage IDD-OLP Off Voltage Internal Sink Current VDD Over-voltage Protection (Turn Off PWM with Delay) VDD Over-Voltage Protection Debounce Conditions Min. Typ. Max. 22 Units V μA mA mA V V V μA V μs VDD – 0.16V VDD=15V, GATE Open VDD=15V, GATE Open, IREF=10mA 15 9 6.5 VTH-OLP +0.1V 70 23.4 VDD-OVP=26V 80 10 6 16 16 10 7.5 80 24.5 100 50 10 20 17 11 8.0 100 25.5 120 Maximum Input Current Internal Current Source RI Voltage Normal PWM Frequency Minimum Frequency in Green Mode RI Range RI Pin Open Protection RI Pin Short Protection VAC=90V(VDC=120V), VDD=10µF HV=500V,VDD=15V 1.5 2.5 10 3.5 50 1.224 68 ±4.7 22 47 mA μA V kHz Oscillator and Green-Mode Operation 1.176 Center Frequency, RI=24kΩ Jitter Range fOSC-G-MIN RI RIOPEN RISHORT RI=24kΩ 62 ±3.7 18 12 If RI > RIOPEN, PWM Turned Off If RI > RISHORT, PWM Turned Off 1 6 1.200 65 ±4.2 20 24 kHz kΩ MΩ kΩ VRMS for AC Brownout Protection VRMS-OFF VRMS-ON tRMS VREF VREF △VREF1 △VREF2 IREF_MAX IOS Reference Voltage Load Regulation of Reference Voltage Line Regulation of Reference Voltage Maximum Current Output Short Circuit 7 Off Threshold Voltage for AC Brownout Protection Start Threshold Voltage for AC Brownout Protection AC Brownout Protection Debounce Time RI=24kΩ 0.75 0.80 0.85 VRMS-UVP-1 +0.21 240 V V ms VRMS-UVP-1 VRMS-UVP-1 +0.17 +0.19 150 195 IREF=1mA, CREF=0.1µF CREF=0.1µF, IREF=1mA to 10mA CREF=0.1µF, VDD=12V to 22V 4.75 5.00 5.25 80 25 V mV mV mA mA 10 15 20 15 25 © 2008 Fairchild Semiconductor Corporation FAN6791 / FAN6793 • Rev. 1.0.2 www.fairchildsemi.com FAN6791 / FAN6793 — Highly Integrated, Dual-PWM Combination Controller Electrical Characteristics VDD=18V; RI=24kΩ;TA =25°C, unless noted. Symbol ON/OFF RON/OFF VON VOFF Parameter Impedance ON/OFF Pin High Threshold Level of Synchronizing Signal Low Threshold Level of Synchronizing Signal Protection Junction (1) Temperature Restart Junction Temperature (2) Conditions Min. 50 2.4 0.8 Typ. Max. 100 Units kΩ V V 3.0 1.0 3.6 1.2 Over Temperature Protection (OTP) TOff TRestart 130 100 140 110 +150 +120 °C °C Flyback PWM Stage FBFYB Feedback Input AV-FLY ZFB VHGH VFB-OLP tOLP VN SG VG VOZ-OFYB FB Input to Current Comparator Attenuation Input Impedance Output High Voltage FB Open-Loop Trigger Level FB Open-Loop Protection Delay Green Mode Entry FB Voltage Slope of Green-Mode Modulation Green Mode Ending FB Voltage VFBPWM for Zero Duty Cycle (Forward Turn On) Input Impedance Peak Current Limit Threshold Voltage 1 Peak Current Limit Threshold Voltage 2 Propagation Delay to GATE Output Leading-Edge Blanking Time Slope Compensation Threshold Voltage for SENSE Short-Circuit Protection Delay Time for SENSE ShortCircuit Protection Flyback PWM Gate Output Clamping Voltage Output Voltage Low Output Voltage High Rising Time Falling Time VSENSE