FAN6751MR

FAN6751MR — Highly-Integrated Green-Mode PWM Controller September 2008 FAN6751MR Highly-Integrated Green-Mode PWM Controller Features High-Voltage Startup Low Operating Current: 4mA Linearly Decreasing PWM Frequency to 18KHz Fixed PWM Frequency: 65KHz Peak-current-mode Control Cycle-by-cycle Current Limiting Leading-edge Blanking (LEB) Synchronized Slope Compensation Internal Open-loop Protection GATE Output Maximum Voltage Clamp: 18V VDD Under-Voltage Lockout (UVLO) VDD Over-Voltage Protection (OVP) Internal Recovery Circuit (OVP, OLP) Internal Sense Short-Circuit Protection External Constant Power Limit (Full AC Input Range) Internal OTP Sensor with Hysteresis Built-in 5ms Soft-Start Function Built-in VIN Pin Pull HIGH (> 4.7V) Recovery Function for Second-Side Output OVP Brownout Protection with Hysteresis Description The highly integrated FAN6751 series of PWM controllers provides several features to enhance the performance of flyback 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 18KHz. 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, FAN6751 is manufactured using the BiCMOS process, which allows an operating current of only 4mA. Built-in synchronized slope compensation achieves stable peak-current-mode control. The proprietary, external line compensation ensures constant output power limit over a wide AC input voltage range, from 90VAC to 264VAC. FAN6751 provides many protection functions. In addition to cycle-by-cycle current limiting, the internal open-loop protection circuit ensures safety should an open-loop or output short-circuit failure occur. PWM output is disabled until VDD drops below the UVLO lower limit, when the controller starts up again. As long as VDD exceeds ~26V, the internal OVP circuit is triggered. FAN6751 is available in an 8-pin SOP package. Applications General-purpose switch-mode power supplies and flyback power converters, including: Power Adapters Open-frame SMPS Ordering Information Part Number FAN6751MRMY Operating Temperature Range -40°C to +105°C Eco Status Green Package 8-Lead, Small Outline Package (SOP-8) Packing Method Tape & Reel For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. © 2008 Fairchild Semiconductor Corporation FAN6751MR • Rev. 1.0.0 www.fairchildsemi.com FAN6751MR — Highly-Integrated Green-Mode PWM Controller Application Diagram Figure 1. Typical Application Internal Block Diagram Figure 2. Functional Block Diagram © 2008 Fairchild Semiconductor Corporation FAN6751MR • Rev. 1.0.0 www.fairchildsemi.com 2 FAN6751MR — Highly-Integrated Green-Mode PWM Controller Marking Information 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 (N:DIP, M:SOP) P: Y=Green package M: Manufacture flow code Figure 3. Top Mark ZXYTT 6751MR TPM Pin Configuration SOP-8 GND FB NC HV 1 2 3 4 8 7 6 5 GATE VDD SENSE VIN Figure 4. Pin Configuration (Top View) Pin Definitions Pin # 1 2 3 4 5 Name GND FB NC HV VIN Description Ground. The signal from the external compensation circuit is fed into this pin. The PWM duty cycle is determined in response to the signal on this pin and the current-sense signal on the SENSE pin. No connection. For startup, this pin is pulled high to the line input or bulk capacitor via resistors. Line-voltage detection. The line-voltage detection is used for brownout protection with hysteresis. Constant output power limit over universal AC input range is also achieved using this VIN pin. It is suggested to add a low pass filter to filter out line ripple on bulk capacitor. VIN pulling high triggers latch protection. Current sense. The sensed voltage is used for peak-current-mode control and cycle-by-cycle current limiting. Power supply. The internal protection circuit disables PWM output as long as VDD exceeds the OVP trigger point. The totem-pole output driver. Soft-driving waveform is implemented for improved EMI. 6 7 8 SENSE VDD GATE © 2008 Fairchild Semiconductor Corporation FAN6751MR • Rev. 1.0.0 www.fairchildsemi.com 3 FAN6751MR — Highly-Integrated Green-Mode PWM 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 VFB VSENSE VVIN VHV PD ΘJA TJ TSTG TL ESD DC Supply Voltage (1, 2) Parameter FB Pin Input Voltage SENSE Pin Input Voltage VIN Pin Input Voltage HV Pin Input Voltage Power Dissipation (TA＜50°C) Thermal Resistance, Junction-to-Air Operating Junction Temperature Storage Temperature Range Lead Temperature (Wave Soldering or IR, 10 Seconds) Electrostatic Discharge Capability, Human Body Model: JESD22-A114 Electrostatic Discharge Capability, Machine Model: JESD22-A115 All pins except HV pin All pins except HV pin Min. -0.3 -0.3 -0.3 Max. 30 7.0 7.0 7.0 500 400 141 Unit V V V V V mW °C/W °C °C °C kV V -40 -55 +150 +150 +260 4 200 Notes: 1. All voltage values, except differential voltages, are given with respect to the network ground terminal. 2. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. © 2008 Fairchild Semiconductor Corporation FAN6751MR • Rev. 1.0.0 www.fairchildsemi.com 4 FAN6751MR — Highly-Integrated Green-Mode PWM Controller Electrical Characteristics VDD=15V, TA=25°C, unless otherwise noted. Symbol VDD Section VOP VDD-ON VDD-OFF IDD-ST IDD-OP IDD-OLP VTH-OLP VDD-OVP tD-VDDOVP Parameter Continuously Operating Voltage Start Threshold Voltage Minimum Operating Voltage Startup Current Operating Supply Current Internal Sink Current IDD-OLP Off Voltage VDD Over-Voltage Protection VDD Over-Voltage Protection Debounce Time Conditions Min. Typ. Max. 22 Units V V V µA mA µA V V µs 15.5 9.5 VDD-ON – 0.16V VDD=15V, GATE Open VTH-OLP+0.1V 30 6.5 25 75 16.5 10.5 17.5 11.5 30 4 70 7.5 26 130 5 90 8.0 27 200 HV Section IHV IHV-LC Supply Current Drawn from HV Pin Leakage Current after Startup VAC=90V (VDC=120V), VDD=10µF, VDD=0V HV=500V, VDD=VDD-OFF+1V Center Frequency 62 14 VDD=11V to 22V TA=-40 to 85°C 2.0 1 3.5 20 mA µA Oscillator Section fOSC fOSC-G fDV fDT Frequency in Nominal Mode Green-Mode Frequency Frequency Variation vs. VDD Deviation Frequency Variation vs. Temperature Deviation PWM Turn-off Threshold Voltage PWM Turn-on Threshold Voltage PWM Latch-off Threshold Voltage PWM Latch-off Debounce Time 65 18 68 22 5 5 KHz KHz % % VIN Section VIN-OFF VIN-ON VIN-LATCH TVIN-LATCH 0.65 VIN-OFF+ 0.20 4.5 60 0.70 VIN-OFF+ 0.22 4.7 100 0.75 VIN-OFF+ 0.24 4.9 140 V V V µs Continued on following page… © 2008 Fairchild Semiconductor Corporation FAN6751MR • Rev. 1.0.0 www.fairchildsemi.com 5 FAN6751MR — Highly-Integrated Green-Mode PWM Controller Electrical Characteristics VDD=15V, TA=25°C, unless otherwise noted. Symbol Parameter Input Voltage to Current-Sense Attenuation Input Impedance Output High Voltage FB Open-loop Trigger Level Delay Time of FB Pin Open-loop Protection Green-Mode Entry FB Voltage Green-Mode Ending FB Voltage Zero Duty-Cycle Input Voltage Conditions Min. Typ. Max. Units Feedback Input Section AV ZFB VFB-OPEN VFB-OLP tD-OLP VFB-N VFB-G VFB-ZDC 1/4.5 4 FB Pin Open 5.5 5.0 5.2 56 2.1 1.6 1.1 5.4 1/4.0 1/3.5 7 V/V kΩ V V ms V V V Current-Sense Section ZSENSE VTH-P at VIN=1V VTH-P at VIN=3V tPD tLEB VS-SCP tD-SSCP TSS Input Impedance Threshold Voltage for Current Limit Threshold Voltage for Current Limit Delay to Output Leading-Edge Blanking Time Threshold Voltage for SENSE ShortCircuit Protection Delay Time for SENSE Short-Circuit Protection Period During Soft-Startup Time VSENSE