SG6901

SG6901A — CCM PFC / Flyback PWM Combination Controller February 2009 SG6901A CCM PFC/Flyback PWM Combination Controller Features Interleaved PFC/PWM Switching Low Startup and Operating Current Innovative Switching Charge Multiplier Divider Multi-vector Control for Improved PFC Output Transient Response Average-Current-Mode Control for PFC Programmable Two-Level PFC Output Voltage Protections PFC and PWM Feedback Open-Loop Protection Cycle-by-Cycle Current Limiting for PFC/PWM Slope Compensation for PWM H/L Line Over-Power Compensation for PWM Brownout Protection Over-Temperature Protection (OTP) Description The highly integrated SG6901A is designed for power supplies with boost PFC and flyback PWM. It requires very few external components to achieve versatile protections. It is available in a 20-pin SOP package. A proprietary interleave-switching feature synchronizes the PFC and PWM stages and reduces switching noise. For PFC stage, the proprietary multi-vector control scheme provides a fast transient response in a lowbandwidth PFC loop, in which the overshoot and undershoot of the PFC voltage are clamped. If the feedback loop is broken, the SG6901A shuts off PFC to prevent extra-high voltage on output. For the flyback PWM, the synchronized slope compensation ensures the stability of the current loop under continuous-conduction-mode operation. Built-in line-voltage compensation maintains constant outputpower limit. Hiccup operation during output overloading is also guaranteed. In addition, SG6901A provides protection functions, such as brownout and RI pin open/short protection. Applications Switching Power Supplies with Active PFC and Standby Power High-Power Adaptors Ordering Information Part Number Operating Temperature Range -30°C to +85°C Eco Status RoHS Package 20-Lead, Small Outline Integrated Packing Method Tape & Reel SG6901ASZ Circuit (SOIC), JEDEC MS013, .300 inch, Wide Body For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com SG6901A — CCM PFC / Flyback PWM Combination Controller Application Circuit Figure 1. Typical Application © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 2 SG6901A — CCM PFC / Flyback PWM Combination Controller Block Diagram Figure 2. Block Diagram © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 3 SG6901A — CCM PFC / Flyback PWM Combination Controller Marking Information T- S=SOP P- Z=Lead Free Null=regular package XXXXXXXX- Wafer Lot Y: Year; WW: Week V: Assembly Location Figure 3. Top Mark Pin Configuration Figure 4. Pin Configuration © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 4 SG6901A — CCM PFC / Flyback PWM Combination Controller Pin Definitions Pin # 1 Name VRMS Description Line voltage detection. The pin is used for PFC multiplier, RANGE control of PFC output voltage, and brownout protection. For brownout protection, the controller is disabled after a delay time when the VRMS voltage drops below a threshold. Reference setting. One resistor connected between RI and ground determines the switching frequency. The switching frequency is equal to [1560 / RI] KHz, where RI is in KΩ. For example, if RI is equal to 24KΩ, the switching frequency is 65KHz. Over-temperature protection. A constant current is output from this pin. An external NTC thermistor must be connected from this pin to ground. The impedance of the NTC thermistor decreases whenever the temperature increases. Once the voltage of the OTP pin drops below the OTP threshold, the SG6901A is disabled. PFC current amplifier output. The signal from this pin is compared with an internal sawtooth to determine the pulse width for PFC gate drive. The inverting input of the PFC current amplifier. Proper external compensation circuits result in excellent input power factor via average-current-mode control. The non-inverting input of the PFC current amplifier and the output of multiplier. Proper external compensation circuits results in excellent input power factor via average-current-mode control. Current limit. A resistor from this pin to GND sets the current limit. The control input for voltage-loop feedback of PWM stage. It is internally pulled high through a 6.5kΩ resistance. Usually an external opto-coupler from secondary feedback circuit is connected to this pin. The current-sense input for the flyback PWM. Via a current sense resistor, this pin provides the control input for peak-current-mode control and cycle-by-cycle current limiting. Signal ground. Soft start. During startup, the SS pin charges an external capacitor with a 50µA (RI=24KΩ) constant current source. The voltage on FBPWM is clamped by SS during startup. In the event of a protection condition occurring and/or PWM being disabled, the SS pin is quickly discharged. The totem-pole output drive for the flyback PWM MOSFET. This pin is internally clamped under 17V to protect the MOSFET. Power ground. The totem-pole output drive for the PFC MOSFET. This pin is internally clamped under 17V to protect the MOSFET. The power supply pin. The RANGE pin has high impedance whenever the VRMS voltage is lower than a threshold. The PFC output voltage at low line can be reduced to improve efficiency. The PFC stage over-voltage input. The comparator disables the PFC output driver if the voltage at this input exceeds a threshold. This pin can be connected to FBPFC or it can be connected to the PFC boost output through a divider network. The feedback input for PFC voltage loop. The inverting input of PFC error amplifier. This pin is connected to the PFC output through a divider network. The error amplifier output for PFC voltage feedback loop. A compensation network (usually a capacitor) is connected between this pin and ground. A large capacitor value results in a narrow bandwidth and improves the power factor. This input is used to provide current reference for the multiplier. 2 RI 3 OTP 4 5 6 7 8 IEA IPFC IMP ISENSE FBPWM 9 10 11 IPWM AGND SS 12 13 14 15 16 17 18 OPWM GND OPFC VDD RANGE OVP FBPFC 19 20 VEA IAC © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 5 SG6901A — CCM PFC / Flyback 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. Symbol VDD IAC VHIGH VLOW PD TJ TSTG ӨJC TL ESD DC Supply Voltage Input AC Current OPWM, OPFC, IAC Others Power Dissipation at TA< 50℃ Parameter Min. Max. 25 2 Unit V mA V V W °C °C °C/W °C KV V -0.3 -0.3 25.0 7.0 1.15 Operating Junction Temperature Storage Temperature Range Thermal Resistance (Junction-to-Case) Lead Temperature (Soldering) Electrostatic Discharge Capability Human Body Model, JESD22-A114 Machine Model, JESD22-A115 -40 -55 +125 +150 +23.64 +260 4.5 250 Notes: 1. All voltage values, except differential voltage, are given with respect to GND pin. 2. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. 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. -30 Max. +85 Unit °C © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 6 SG6901A — CCM PFC / Flyback PWM Combination Controller Electrical Characteristics VDD=15V and TA=25°C unless otherwise specified. Symbol VDD SECTION VDD-OP IDD-ST IDD-OP VDD-ON VDD-OFF VDD-OVP tD-VDDOVP Parameter Continuously Operating Voltage Startup Current Operating Current Start Threshold Voltage Minimum Operating Voltage VDD OVP Threshold Debounce Time of VDD OVP Conditions Min. Typ. Max. 20 Units V µA mA V V V µs 0V < VDD < VDD-ON VDD=15V; OPFC, OPWM Open; RI=24KΩ 11 9 23.5 8 10 6 12 10 24.5 25 10 13 11 25.5 25 OSCILLATOR SECTION fOSC RI RI-OPEN RI-SHORT PWM Frequency RI Pin Resistance Range RI Pin Open Protection RI Pin Short Protection If RI>RI-OPEN, SG6901A Turns Off If RI (+)) Open-Loop Gain Unit Gain Bandwidth Common Mode Rejection Ratio Output High Voltage Output Low Voltage Reference Current Source Maximum Source Current Maximum Sink Current RI=24KΩ (IMR=20+IRI•0.8) 50 3 0.25 VCM=0 to +1.5V 3.2 0.2 70 8 60 1.5 70 mV dB MHz dB V V µA mA mA Continued on the following page… © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 8 SG6901A — CCM PFC / Flyback PWM Combination Controller Electrical Characteristics VDD=15V and TA=25°C unless otherwise specified. Symbol PEAK CURRENT LIMIT IP VPK tPD-PFC tLEB-PFC MULTIPLIER IAC IMO–max IMO-1 IMO–2 VIMP Parameter Constant Current Output Conditions RI=24KΩ Min. 90 0.15 0.35 Typ. 100 0.20 0.40 Max. 110 0.25 0.45 200 Units µA V V ns ns Peak Current Limit Threshold VRMS=1.05V Voltage Cycle-by-Cycle Limit (VSENSE VRMS=3V < VPK) Propagation Delay Leading-Edge Blanking Time 270 350 450 Input AC Current Maximum Multiplier Current Output Multiplier Current Output (Low-line, High-Power) Multiplier Current Output (High-line, High-Power) Voltage of IMP Open Multiplier Linear Range RI=24KΩ VRMS=1.05V; IAC=90µA; VEA=7.5V; RI=24KΩ VRMS=3V; IAC=264µA; VEA=7.5V; RI=24KΩ 0 250 200 65 3.4 250 85 3.9 360 µA µA 280 µA µA 4.4 V PFC OUTPUT DRIVER VZ VOL-PFC tPFC VOH-PFC tR-PFC tF-PFC DCYMAX PWM STAGE FBPWM Av-PWM ZFB IFB FB to Current Comparator Attenuation Input Impedance Maximum Source Current 2.5 4 0.8 4.2 45 450 3.1 5 1.2 4.5 56 600 3.5 7 1.5 4.8 70 750 V/V KΩ mA V ms ms Output Voltage Maximum (Clamp) Output Voltage Low Interval OPFC Lags Behind OPWM at Startup Output Voltage High Rising Time Falling Time Maximum Duty Cycle VDD=13V; IO=100mA VDD=15V; CL=5nF; O/P=2V to 9V VDD=15V; CL=5nF; O/P=9V to 2V VDD=20V VDD=15V; IO=100mA 9.0 8 40 40 93 70 60 120 110 98 11.5 16 18 1.5 14.0 V V ms V ns ns % FBOPEN-LOOP PWM Open-Loop Protection Voltage tOPEN-PWM tOPEN-PWMHiccup PWM Open-Loop Protection Delay Time Interval of PWM Open-Loop Protection Reset Continued on the following page… © 2008 Fairchild Semiconductor Corporation SG6901A • Rev. 1.0.2 www.fairchildsemi.com 9 SG6901A — CCM PFC / Flyback PWM Combination Controller Electrical Characteristics VDD=15V and TA=25°C unless otherwise specified. Symbol Parameter Propagation Delay to Output Peak Current Limit Threshold Voltage1 Peak Current Limit Threshold Voltage2 Leading-Edge Blanking Time Conditions Min. Typ. Max. Units PWM CURRENT SENSE tPD-PWM VLIMIT-1 VLIMIT-2 tLEB-PWM VDD=15V, OPWM