FSQ0765RQ FAIRCHILD | Alldatasheet
Document overview
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Technical content
Features
! Optimized for Quasi-Resonant Converter (QRC) ! Low EMI through Variable Frequency Control and AVS (Alternating Valley Switching) ! High-Efficiency through Minimum Voltage Switching ! Narrow Frequency Variation Range over Wide Load and Input Voltage Variation ! Advanced Burst-Mode Operation for Low Standby Power Consumption ! Simple Scheme for Sync Voltage Detection ! Pulse-by-Pulse Current Limit ! Various Protection functions: Overload Protection (OLP), Over-Voltage Protection (OVP), Abnormal Over-Current Protection (AOCP), Internal Thermal Shutdown (TSD) with Hysteresis, Output Short Protection (OSP) ! Under-Voltage Lockout (UVLO) with Hysteresis ! Internal Startup Circuit ! Internal High-Voltage Sense FET (650V) ! Built-in Soft-Start (17.5ms)
Applications
! Power Supply for LCD TV and Monitor, VCR, SVR, STB, and DVD & DVD Recorder ! Adapter Related Resources Visit http://www.fairchildsemi.com/apnotes/ for: ! AN-4134: Design Guidelines for Offline Forward Converters Using Fairchild Power Switch (FPS) ! AN-4137: Design Guidelines for Offline Flyback Converters Using Fairchild Power Switch (FPS) ! AN-4140: Transformer Design Consideration for Offline Flyback Converters Using Fairchild Power Switch (FPS ! AN-4141: Troubleshooting and Design Tips for Fairchild Power Switch (FPS) Flyback Applications ! AN-4145: Electromagnetic Compatibility for Power Converters ! AN-4147: Design Guidelines for RCD Snubber of Flyback ! AN-4148: Audible Noise Reduction Techniques for Fairchild Power Switch Fairchild Power Switch(FPS ! AN-4150: Design Guidelines for Flyback Converters Using FSQ-Series Fairchild Power Switch (FPS)
Description
A Quasi-Resonant Converter (QRC) generally shows lower EMI and higher power conversion efficiency than a conventional hard-switched converter with a fixed switching frequency. The FSQ-series is an integrated Pulse-Width Modulation (PWM) controller and SenseFET specifically designed for quasi-resonant operation and Alternating Valley Switching (AVS). The PWM controller includes an integrated fixed-frequency oscillator, Under-Voltage Lockout (UVLO), Leading- Edge Blanking (LEB), optimized gate driver, internal soft- start, temperature-compensated precise current sources for a loop compensation, and self-protection circuitry. Compared with a discrete MOSFET and PWM controller solution, the FSQ-series can reduce total cost, component count, size, and weight; while simultaneously increasing efficiency, productivity, and system reliability. This device provides a basic platform that is well suited for cost-effective designs of quasi-resonant switching flyback converters.
FSQ0765RQ Green-Mode Farichild Power Switch (FPS) for Quasi-Resonant Operation © 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com FSQ0765RQ Rev. 1.0.1 2
Ordering Information
Notes: 1. The junction temperature can limit the maximum output power. 2. 230VAC or 100/115VAC with doubler. 3. Typical continuous power in a non-ventilated enclosed adapter measured at 50°C ambient temperature. 4. Maximum practical continuous power in an open-frame design at 50°C ambient. 5. For Fairchilds definition of green Eco Status, please visit: Product Number PKG.(5) Operating Temp. Current Limit RDS(ON) Max. Maximum Output Power(1) Replaces Devices 230VAC±15%(2) 85-265VAC Adapter(3) Open Frame(4) Adapter(3) Open Frame(4) FSQ0765RQWDTU TO-220F-6L -25 to +85°C 3.5A 1.6 Ω 80W 90W 48W 70W FSCM0765R FSDM0765RB
Figure 3. Pin Configuration (Top View) 1D r a i n SenseFET drain. High-voltage power SenseFET drain connection. 2G N D Ground. This pin is the control ground and the SenseFET source. both startup and steady-state operation. triggers, which shuts down the FPS. 5 Sync Sync. This pin is internally connected to the sync-detect comparator for quasi-resonant switching. In normal quasi-resonant operation, the threshold of the sync comparator is 1.2V/1.0V. capacitor connected to the VCC pin. Once VCC reaches 12V, the internal current source is disabled. It is not recommended to connect Vstr and Drain together.
FSQ0765RQ Green-Mode Farichild Power Switch (FPS) for Quasi-Resonant Operation © 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com FSQ0765RQ Rev. 1.0.1 5 Absolute Maximum Ratings Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be opera- ble above the recommended operating conditions and stressing the parts to these levels is not recommended. In addi- tion, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. TA = 25°C, unless otherwise specified. Notes: 6. Repetitive rating: Pulse width limited by maximum junction temperature. 7. L=81mH, starting TJ=25°C. Thermal Impedance TA = 25°C unless otherwise specified. Notes: 8. Free standing with no heat-sink under natural convection. 9. Infinite cooling condition - refer to the SEMI G30-88. Symbol Parameter Min. Max. Unit Vstr Vstr Pin Voltage 500 V VDS Drain Pin Voltage 650 V VCC Supply Voltage 20 V VFB Feedback Voltage Range -0.3 13.0 V VSync Sync Pin Voltage -0.3 13.0 V IDM Drain Current Pulsed 14.4 A ID Continuous Drain Current(6) TC = 25°C 3.6 A TC = 100°C 2.28 EAS Single Pulsed Avalanche Energy(7) 570 mJ PD Total Power Dissipation(Tc=25°C) 45 W TJ Operating Junction Temperature Internally limited °C TA Operating Ambient Temperature -25 +85 °C TSTG Storage Temperature -55 +150 °C ESD Electrostatic Discharge Capability Human Body Model 2 kV Charged Device Model 2 Symbol Parameter Value Unit θJA Junction-to-Ambient Thermal Resistance(8) 50 °C/W θJC Junction-to-Case Thermal Resistance(9) 2.8 °C/W
FSQ0765RQ Green-Mode Farichild Power Switch (FPS) for Quasi-Resonant Operation © 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com FSQ0765RQ Rev. 1.0.1 6
Electrical Characteristics
TA = 25°C unless otherwise specified. Note: 10. Propagation delay in the control IC. Continued on the following page... Symbol Parameter Condition Min. Typ. Max. Unit SENSEFET SECTION BVDSS Drain Source Breakdown Voltage V CC = 0V, ID = 100µA 650 V IDSS Zero-Gate-Voltage Drain Current V DS = 520V, VGS = 0V 300 µA RDS(ON) Drain-Source On-State Resistance T J = 25°C, ID = 1.8A 1.3 1.6 Ω COSS Output Capacitance V GS = 0V, VDS = 25V, f = 1MHz 125 pF td(on) Turn-On Delay Time VDD = 325V, ID = 6.5A 27 ns tr Rise Time 102 ns td(off) Turn-Off Delay Time 63 ns tf Fall Time 65 ns CONTROL SECTION tON.MAX Maximum On Time T J = 25°C 8.8 10.0 11.2 µs tB Blanking Time T J = 25°C, Vsync = 5V 13.5 15.0 16.5 µs tW Detection Time Window T J = 25°C, Vsync = 0V 6.0 µs fS Initial Switching Frequency 59.6 66.7 75.8 kHz ΔfS Switching Frequency Variation(11) -25°C < TJ < 85°C ±5 ±10 % tAVS AVS Triggering Threshold(11) On Time at VIN = 240VDC, Lm = 360μH (AVS triggered when VAVS>spec & tAVS<spec.) 4.0 µs VAVS Feedback Voltage 1.2 V tSW Switching Time Variance by AVS(11) Sync = 500kHz sine input VFB = 1.2V, tON = 4.0µs 13.5 20.5 µs IFB Feedback Source Current V FB = 0V 700 900 1100 µA DMIN Minimum Duty Cycle V FB = 0V 0 % VSTART UVLO Threshold Voltage 11 12 13 V VSTOP After turn-on 7 8 9 V tS/S Internal Soft-Start Time With free-running frequency 17.5 ms BURST-MODE SECTION VBURH Burst-Mode Voltages T J = 25°C, tPD = 200ns(10) 0.45 0.55 0.65 V VBURL 0.25 0.35 0.45 V Hysteresis 200 mV
FSQ0765RQ Green-Mode Farichild Power Switch (FPS) for Quasi-Resonant Operation © 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com FSQ0765RQ Rev. 1.0.1 7 Electrical Characteristics (Continued) TA = 25°C unless otherwise specified. Notes: 11. Guaranteed by design, but not tested in production. 12. Includes gate turn-on time. Symbol Parameter Condition Min. Typ. Max. Unit PROTECTION SECTION ILIMIT Peak Current Limit T J = 25°C, di/dt = 460mA/µs 3.08 3.50 3.92 A VSD Shutdown Feedback Voltage V CC = 15V 5.5 6.0 6.5 V IDELAY Shutdown Delay Current V FB = 5V 4 5 6 µA tLEB Leading-Edge Blanking Time(11) 250 ns tOSP Output Short Protection(11) Threshold Time TJ = 25°C OSP triggered when tON<tOSP , VFB>VOSP & lasts longer than tOSP_FB 1.2 1.4 µs VOSP Threshold Feedback Voltage 1.8 2.0 V tOSP_FB Feedback Blanking Time 2.0 2.5 3.0 µs TSD Thermal Shutdown(11) Shutdown Temperature 125 140 155 Hys Hysteresis 60 SYNC SECTION VSH1 Sync Threshold Voltage 1 V CC = 15V, VFB = 2V 1.0 1.2 1.4 V VSL1 0.8 1.0 1.2 tsync Sync Delay Time(11)(12) 230 ns VSH2 Sync Threshold Voltage 2 V CC = 15V, VFB = 2V 4.3 4.7 5.1 V VSL2 4.0 4.4 4.8 VCLAMP Low Clamp Voltage ISYNC_MAX = 800µA ISYNC_MIN = 50µA 0.0 0.4 0.8 V VOVP Over-Voltage Protection Threshold Voltage V CC = 15V, VFB=2V 7.4 8.0 8.6 V tOVP Blanking Time(11) 1.0 1.7 2.4 µs TOTAL DEVICE SECTION IOP Operating Supply Current (Control Part Only) VCC = 13V, VFB=0V 1 3 5 mA ISTART Start Current VCC = 10V (before VCC reaches VSTART) 350 450 550 µA ICH Startup Charging Current V CC = 0V, VSTR = minimum 50V 0.65 0.85 1.00 mA VSTR Minimum VSTR Supply Voltage 26 V
FSQ0765RQ Green-Mode Farichild Power Switch (FPS) for Quasi-Resonant Operation © 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com FSQ0765RQ Rev. 1.0.1 8 Comparison Between FSDM0x65RNB and FSQ-Series Function FSDM0x65RE FSQ-Series FSQ-Series Advantages Operation Method Constant Frequency PWM Quasi-Resonant Operation ! Improved efficiency by valley switching ! Reduced EMI noise ! Reduced components to detect valley point EMI Reduction Frequency Modulation Reduce EMI Noise ! Valley switching ! Inherent frequency modulation ! Alternate valley switching Hybrid Control CCM or AVS Based on Load and Input Condition ! Improves efficiency by introducing hybrid control Burst-Mode Operation Burst-Mode Operation Advanced Burst-Mode Operation ! Improved standby power by AVS in burst-mode Strong Protections OLP, OVP OLP, OVP, AOCP, OSP ! Improved reliability through precise AOCP ! Improved reliability through precise OSP TSD 145°C without Hysteresis 140°C with 60°C Hysteresis ! Stable and reliable TSD operation ! Converter temperature range
- Startup: At startup, an internal high-voltage current
Figure 22. Startup Circuit
- Feedback Control: FPS employs current-mode
are typically used to impl ement the feedback network. increased or the output load is decreased.
2.1 Pulse-by-Pulse Current Limit: Because current-
through the SenseFET is limited.
2.2 Leading-Edge Blanking (LEB): At the instant the
LEB) after the SenseFET is turned on. Figure 23. Pulse-Width-Modulation (PWM) Circuit
- Synchronization: The FSQ-series employs a quasi-
winding voltage, as shown in Figure 24. Figure 24. Quasi-Resonant Switching Waveforms
4 OSC
4.1 Overload Protection (OLP): Overload is defined as
protection circuit should trigger to protect the SMPS. 20 ~ 50ms delay time is typical for most applications. Figure 29. Overload Protection
4.2 Abnormal Over-Current Protection (AOCP): When
Figure 30. Abnormal Over-Current Protection
4.3 Output-Short Protection (OSP): If the output is
abnormal condition output short is shown in Figure 31. Figure 31. Output Short Waveforms
4.4 Over-Voltage Protection (OVP): If the secondary-
in the breakdown of the de vices in the secondary side.
points to be considered, which are depicted in Figure 32. Figure 32. OVP Triggering
4.5 Thermal Shutdown with Hysteresis (TSD): The
SenseFET and the control IC are built in one package. CC reaches startup voltage (Vstart).
- Soft-Start: The FPS has an internal soft-start circuit
stress on the secondary diode during startup.
- Burst Operation: To minimize power dissipation in
thereby reducing switching loss in standby mode. Figure 33. Waveforms of Burst Operation
- Switching Frequency Limit: To minimize switching
topology in a wide range of applications. frequency-limit function, as shown in Figures 34 and 35. shown in Figures 34 and Figure 35 (Cases A, B, and C).
the same trace and meet only at one point, the GND pin. currents by decreasing resistance. connect to the signal ground (not power ground). traces should not draw across or close to the drain line. using jumper wires for power ground and drain. Mylar® is a registered trademark of DuPont Teijin Films. Figure 37. Recommended PCB Layout
Figure 38. 6-Lead, TO-220 Package specifically the warranty therein, which covers Fairchild products. http://www.fairchildsemi.com/packaging/.
FSQ0765RQ Green-Mode Farichild Power Switch (FPS) for Quasi-Resonant Operation © 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com FSQ0765RQ Rev. 1.0.1 19