FSL136HR Green Mode Fairchild Power Switch (FPS™) Features Description The FSL136HR integrated Pulse Width Modulator (PWM) and SenseFET is specifically designed for highperformance offline Switch-Mode Power Supplies (SMPS) with minimal external components. FSL136HR includes integrated high-voltage power switching regulators that combine an avalanche-rugged SenseFET with a current-mode PWM control block. Internal Avalanche-Rugged SenseFET (650V) Under 50mW Standby Power Consumption at 265VAC, No-load Condition with Burst Mode Precision Fixed Operating Frequency with Frequency Modulation for Attenuating EMI Internal Startup Circuit Built-in Soft-Start: 20ms Pulse-by-Pulse Current Limiting Various Protections: Over-Voltage Protection (OVP), Overload Protection (OLP), Output-Short Protection (OSP), Abnormal Over-Current Protection (AOCP), Internal Thermal Shutdown Function with Hysteresis (TSD) Auto-Restart Mode Under-Voltage Lockout (UVLO) Low Operating Current: 1.8mA Adjustable Peak Current Limit The integrated PWM controller includes: Under-Voltage Lockout (UVLO) protection, Leading-Edge Blanking (LEB), a frequency generator for EMI attenuation, an optimized gate turn-on/turn-off driver, Thermal Shutdown (TSD) protection, and temperaturecompensated precision current sources for loop compensation and fault protection circuitry. The FSL136HR offers good soft-start performance. When compared to a discrete MOSFET and controller or RCC switching converter solution, the FSL136HR reduces total component count, design size, and weight; while increasing efficiency, productivity, and system reliability. This device provides a basic platform that is well suited for the design of cost-effective flyback converters. FSL136HR — Green Mode Fairchild Power Switch (FPS™) March 2011 Applications Maximum Output Power(1) SMPS for VCR, STB, DVD, & DVCD Players 230VAC ± 15%(2) SMPS for Home Appliance Adapter Adapter(3) Open Frame 19W 26W Related Resources AN-4137-Design Guidelines for Off-line Flyback Converters Using FPS™ Notes: AN-4141-Troubleshooting and Design Tips for Fairchild Power Switch (FPS™) Flyback Applications 2. 3. AN-4147-Design Guidelines for RCD Snubber of Flyback 1. 85-265VAC (3) Adapter 14W Open Frame 20W The junction temperature can limit the maximum output power. 230VAC or 100/115VAC with doubler. Typical continuous power in a non-ventilated enclosed adapter measured at 50C ambient. Ordering Information Part Number Operating Temperature Range FSL136HR -40 to 105°C © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 Top Mark Package FSL136HR 8-Lead, Dual Inline Package (DIP) Packing Method Rail www.fairchildsemi.com FSL136HR — Green Mode Fairchild Power Switch (FPS™) Typical Application Diagram Figure 1. Typical Application Internal Block Diagram Figure 2. Internal Block Diagram © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 2 Figure 3. Pin Configuration Pin Definitions Pin # Name 1 GND Ground. SenseFET source terminal on the primary side and internal control ground. VCC Positive Supply Voltage Input. Although connected to an auxiliary transformer winding, current is supplied from pin 5 (VSTR) via an internal switch during startup (see Internal Block Diagram Section). Once VCC reaches the UVLO upper threshold (12V), the internal startup switch opens and device power is supplied via the auxiliary transformer winding. 3 VFB Feedback Voltage. The non-inverting input to the PWM comparator, it has a 0.4mA current source connected internally, while a capacitor and opto-coupler are typically connected externally. There is a delay while charging external capacitor CFB from 2.4V to 6V using an internal 5µA current source. This delay prevents false triggering under transient conditions, but still allows the protection mechanism to operate under true overload conditions. 4 IPK Peak Current Limit. Adjusts the peak current limit of the SenseFET. The feedback 0.4mA current source is diverted to the parallel combination of an internal 6kΩ resistor and any external resistor to GND on this pin to determine the peak current limit. 5 VSTR Startup. Connected to the rectified AC line voltage source. At startup, the internal switch supplies internal bias and charges an external storage capacitor placed between the VCC pin and ground. Once VCC reaches 12V, the internal switch is opened. 6, 7, 8 Drain Drain. Designed to connect directly to the primary lead of the transformer and capable of switching a maximum of 650V. Minimizing the length of the trace connecting these pins to the transformer decreases leakage inductance. 2 Description © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 3 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Pin Configuration 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. TJ=25°C, unless otherwise specified. Symbol Parameter Min. Max. Unit VSTR VSTR Pin Voltage -0.3 650.0 V VDS Drain Pin Voltage -0.3 650.0 V VCC Supply Voltage 26 V VFB Feedback Voltage Range 12.0 V ID Continuous Drain Current 3 A 12 A IDM -0.3 (4) Drain Current Pulsed (5) EAS Single Pulsed Avalanche Energy 230 mJ PD Total Power Dissipation 1.5 W TJ Operating Junction Temperature TA Operating Ambient Temperature -40 +105 °C Storage Temperature -55 +150 °C TSTG Internally Limited (6) ESD JA JC JT 5.0 Human Body Model, JESD22-A114 (6) Charged Device Model, JESD22-C101 Junction-to-Case Thermal Resistance KV 1.5 Junction-to-Ambient Thermal Resistance(7)(8) (7)(9) (7)(10) Junction-to-Top Thermal Resistance °C 80 °C/W 19 °C/W 33.7 °C/W Notes: 4. Repetitive rating: pulse width limited by maximum junction temperature. 5. L=51mH, starting TJ=25°C. 6. Meets JEDEC standards JESD 22-A114 and JESD 22-C101. 7. All items are tested with the standards JESD 51-2 and JESD 51-10 (DIP package). 8. JA free-standing, with no heat-sink, under natural convection. 9. JC junction-to-lead thermal characteristics under JA test condition. TC is measured on the source #7 pin closed to plastic interface for JA thermo-couple mounted on soldering. 10. JT junction-to-top of thermal characteristic under JA test condition. Tt is measured on top of package. Thermocouple is mounted in epoxy glue. © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 4 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Absolute Maximum Ratings TA = 25C unless otherwise specified. Symbol Parameter Conditions Min. Typ. Max. Units SenseFET Section BVDSS Drain Source Breakdown Voltage VCC = 0V, ID = 250µA IDSS Zero Gate Voltage Drain Current VDS = 650V, VGS = 0V RDS(ON) 650 V 250 Drain-Source On-State Resistance VGS = 10V, VGS = 0V, TC = 25°C 3.5 CISS Input Capacitance VGS = 0V, VDS = 25V, f = 1MHz 290 pF COSS Output Capacitance VGS = 0V, VDS = 25V, f = 1MHz 45 pF CRSS Reverse Transfer Capacitance VGS = 0V, VDS = 25V, f = 1MHz 5.5 pF td(ON) Turn-On Delay VDD = 350V, ID = 3.5A 12 ns Rise Time VDD = 350V, ID = 3.5A 22 ns Turn-Off Delay VDD = 350V, ID = 3.5A 20 ns Fall Time VDD = 350V, ID = 3.5A 19 ns tr td(OFF) tf 4.0 µA Ω Control Section fOSC ∆fOSC Switching Frequency VDS = 650V, VGS = 0V Switching Frequency Variation VGS = 10V, VGS = 0V, TC = 125°C 90 100 110 KHz ±5 ±10 % fFM Frequency Modulation DMAX Maximum Duty Cycle VFB = 4V 71 77 83 % DMIN Minimum Duty Cycle VFB = 0V 0 0 0 % 11 12 13 V 7 8 9 V VSTART VSTOP ±3 UVLO Threshold Voltage After Turn-On KHz IFB Feedback Source Current VFB = 0V 320 400 480 µA tS/S Internal Soft-Start Time VFB = 4V 15 20 25 ms 0.4 0.5 0.6 V 0.25 0.35 0.45 V Burst Mode Section VBURH VBURL TJ = 25°C Burst Mode Voltage VBUR(HYS) 150 mV Protection Section ILIM Peak Current Limit tCLD Current Limit Delay Time(11) VSD Shutdown Feedback Voltage VCC = 15V 5.5 6.0 6.5 V IDELAY Shutdown Delay Current VFB = 5V 3.5 5.0 6.5 µA VOVP Over-Voltage Protection Threshold VFB = 2V 22.5 tOSP VOSP tOSP_FB VAOCP TSD HYSTSD tLEB TJ = 25°C, di/dt = 300mA/µs 2.15 2.41 200 Threshold Time Threshold Feedback Output Short (11) Voltage Protection Feedback Blanking Time (11) TJ = 25°C OSP Triggered When tON<tOSP, VFB>VOSP and Lasts Longer than tOSP_FB TJ = 25°C AOCP Voltage Thermal Shutdown(11) 1.89 Shutdown Temperature 24.0 25.5 V 1.00 1.35 µs 1.44 1.60 V 2.0 2.5 µs 0.85 1.00 1.15 V 125 137 150 °C Hysteresis 60 (11) Leading-Edge Blanking Time A ns 300 °C ns Continued on the following page… © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 5 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Electrical Characteristics TA = 25C unless otherwise specified. Symbol Parameter Conditions Min. Typ. Max. Units Total Device Section IOP1 Operating Supply Current (While Switching) IOP2 ICH VSTR (11) VCC = 14V, VFB > VBURH 2.5 3.5 mA Operating Supply Current (Control Part Only) VCC = 14V, VFB < VBURL 1.8 2.5 mA Startup Charging Current VCC = 0V 1.10 1.30 mA Minimum VSTR Supply Voltage VCC = VFB = 0V, VSTR Increase 0.90 35 V Note: 11. Though guaranteed by design, it is not 100% tested in production. © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 6 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Electrical Characteristics (Continued) These characteristic graphs are normalized at TA=25. Figure 4. Operating Frequency vs. Temperature Figure 5. Maximum Duty Cycle vs. Temperature Figure 6. Operating Supply Current vs. Temperature Figure 7. Start Threshold Voltage vs. Temperature Figure 8. Stop Threshold Voltage vs. Temperature Figure 9. Feedback Source Current vs. Temperature © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 7 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Typical Performance Characteristics These characteristic graphs are normalized at TA=25. Figure 10. Startup Charging Current vs. Temperature Figure 11. Peak Current Limit vs. Temperature Figure 12. Burst Operating Supply Current vs. Temperature Figure 13. Over Voltage Protection vs. Temperature © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 8 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Typical Performance Characteristics (Continued) Startup Feedback Control At startup, an internal high-voltage current source supplies the internal bias and charges the external capacitor (CA) connected with the VCC pin, as illustrated in Figure 14. When VCC reaches the start voltage of 12V, the FPS™ begins switching and the internal highvoltage current source is disabled. The FPS continues normal switching operation and the power is provided from the auxiliary transformer winding unless VCC goes below the stop voltage of 8V. The FSL136HR employs current-mode control, as shown in Figure 16. An opto-coupler (such as the FOD817A) and shunt regulator (such as the KA431) are typically used to implement the feedback network. Comparing the feedback voltage with the voltage across the RSENSE resistor makes it possible to control the switching duty cycle. When the shunt regulator reference pin voltage exceeds the internal reference voltage of 2.5V, the opto-coupler LED current increases, the feedback voltage VFB is pulled down, and the duty cycle is reduced. This typically occurs when the input voltage is increased or the output load is decreased. Figure 14. Startup Circuit Figure 16. Pulse-Width-Modulation Circuit Oscillator Block Leading-Edge Blanking (LEB) The oscillator frequency is set internally and the FPS has a random frequency fluctuation function. Fluctuation of the switching frequency of a switched power supply can reduce EMI by spreading the energy over a wider frequency range than the bandwidth measured by the EMI test equipment. The amount of EMI reduction is directly related to the range of the frequency variation. The range of frequency variation is fixed internally; however, its selection is randomly chosen by the combination of external feedback voltage and internal free-running oscillator. This randomly chosen switching frequency effectively spreads the EMI noise nearby switching frequency and allows the use of a costeffective inductor instead of an AC input line filter to satisfy the world-wide EMI requirements. At the instant the internal SenseFET is turned on, the primary-side capacitance and secondary-side rectifier diode reverse recovery typically cause a high-current spike through the SenseFET. Excessive voltage across the RSENSE resistor leads to incorrect feedback operation in the current mode PWM control. To counter this effect, the FPS employs a leading-edge blanking (LEB) circuit (see the Figure 16). This circuit inhibits the PWM comparator for a short time (tLEB) after the SenseFET is turned on. Protection Circuits The FPS has several protective functions, such as overload protection (OLP), over-voltage protection (OVP), output-short protection (OSP), under-voltage lockout (UVLO), abnormal over-current protection (AOCP), and thermal shutdown (TSD). Because these various protection circuits are fully integrated in the IC without external components, the reliability is improved without increasing cost. Once a fault condition occurs, switching is terminated and the SenseFET remains off. This causes VCC to fall. When VCC reaches the UVLO stop voltage VSTOP (8V), the protection is reset and the internal high-voltage current source charges the VCC capacitor via the VSTR pin. When VCC reaches the UVLO start voltage VSTART (12V), the FPS resumes normal operation. In this manner, the auto-restart can alternately enable and disable the switching of the power SenseFET until the fault condition is eliminated. Figure 15. Frequency Fluctuation Waveform © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 9 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Functional Description Abnormal Over-Current Protection (AOCP) When the secondary rectifier diodes or the transformer pin are shorted, a steep current with extremely high di/dt can flow through the SenseFET during the LEB time. Even though the FPS has OLP (Overload Protection), it is not enough to protect the FPS in that abnormal case, since severe current stress is imposed on the SenseFET until OLP triggers. The FPS includes the internal AOCP (Abnormal Over-Current Protection) circuit shown in Figure 19. When the gate turn-on signal is applied to the power SenseFET, the AOCP block is enabled and monitors the current through the sensing resistor. The voltage across the resistor is compared with a preset AOCP level. If the sensing resistor voltage is greater than the AOCP level, the set signal is applied to the latch, resulting in the shutdown of the SMPS. Figure 17. Auto-Restart Protection Waveforms Overload Protection (OLP) Overload is defined as the load current exceeding a preset level due to an unexpected event. In this situation, the protection circuit should be activated to protect the SMPS. However, even when the SMPS is operating normally, the overload protection (OLP) circuit can be activated during the load transition or startup. To avoid this undesired operation, the OLP circuit is designed to be activated after a specified time to determine whether it is a transient situation or a true overload situation. Thermal Shutdown (TSD) The SenseFET and the control IC are integrated, making it easier for the control IC to detect the temperature of the SenseFET. When the temperature exceeds approximately 137°C, thermal shutdown is activated. In conjunction with the IPK current limit pin (if used), the current-mode feedback path limits the current in the SenseFET when the maximum PWM duty cycle is attained. If the output consumes more than this maximum power, the output voltage (VO) decreases below its rating voltage. This reduces the current through the opto-coupler LED, which also reduces the opto-coupler transistor current, thus increasing the feedback voltage (VFB). If VFB exceeds 2.4V, the feedback input diode is blocked and the 5µA current source (IDELAY) slowly starts to charge CFB. In this condition, VFB increases until it reaches 6V, when the switching operation is terminated, as shown in Figure 18. The shutdown delay is the time required to charge CFB from 2.4V to 6V with 5µA current source. Over-Voltage Protection (OVP) In the event of a malfunction in the secondary-side feedback circuit or an open feedback loop caused by a soldering defect, the current through the opto-coupler transistor becomes almost zero. Then, VFB climbs up in a similar manner to the overload situation, forcing the preset maximum current to be supplied to the SMPS until the overload protection is activated. Because excess energy is provided to the output, the output voltage may exceed the rated voltage before the overload protection is activated, resulting in the breakdown of the devices in the secondary side. To prevent this situation, an over-voltage protection (OVP) circuit is employed. In general, VCC is proportional to the output voltage and the FPS uses VCC instead of directly monitoring the output voltage. If VCC exceeds 24V, OVP circuit is activated, resulting in termination of the switching operation. To avoid undesired activation of OVP during normal operation, VCC should be designed to be below 24V. Output-Short Protection (OSP) If the output is shorted, the steep current with extremely high di/dt can flow through the SenseFET during the LEB time. Such a steep current brings high-voltage stress on the drain of SenseFET when turned off. To protect the device from such an abnormal condition, Figure 18. Overload Protection (OLP) © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 10 FSL136HR — Green Mode Fairchild Power Switch (FPS™) Figure 19. Abnormal Over-Current Protection Figure 20. Output Short Waveforms (OSP) Soft-Start The FPS has an internal soft-start circuit that slowly increases the feedback voltage, together with the SenseFET current after it starts. The typical soft-start time is 20ms, as shown in Figure 21, where progressive increments of the SenseFET current are allowed during the startup phase. The pulse width to the power switching device is progressively increased to establish the correct working conditions for transformers, inductors, and capacitors. The voltage on the output capacitors is progressively increased with the intention of smoothly establishing the required output voltage. Soft-start helps prevent transformer saturation and reduce the stress on the secondary diode. Figure 22. Burst-Mode Operation Adjusting Peak Current Limit As shown in Figure 23, a combined 6kΩ internal resistance is connected to the non-inverting lead on the PWM comparator. An external resistance of Rx on the current limit pin forms a parallel resistance with the 6kΩ when the internal diodes are biased by the main current source of 400µA. For example, FSL136HR has a typical SenseFET peak current limit (ILIM) of 2.15A. ILIM can be adjusted to 1.5A by inserting Rx between the IPK pin and the ground. The value of the Rx can be estimated by the following equations: 2.15A:1.5A 6kΩ: XkΩ (1) X Rx || 6kΩ (2) where X is the resistance of the parallel network. Figure 21. Internal Soft-Start Burst Operation To minimize power dissipation in standby mode, the FPS enters burst mode. As the load decreases, the feedback voltage decreases. As shown in Figure 22, the device automatically enters burst mode when the feedback voltage drops below VBURH. Switching continues until the feedback voltage drops below VBURL. At this point, switching stops and the output voltages drop at a rate dependent on standby current load. This causes the feedback voltage to rise. Once it passes VBURH, switching resumes. The feedback © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 Figure 23. Peak Current Limit Adjustment www.fairchildsemi.com 11 FSL136HR — Green Mode Fairchild Power Switch (FPS™) voltage then falls and the process repeats. Burst mode alternately enables and disables switching of the SenseFET and reduces switching loss in standby mode. OSP detects VFB and SenseFET turn-on time. When the VFB is higher than 1.6V and the SenseFET turn-on time is lower than 1.2µs, the FPS recognizes this condition as an abnormal error and shuts down PWM switching until VCC reaches VSTART again. An abnormal condition output is shown in Figure 20. FSL136HR — Green Mode Fairchild Power Switch (FPS™) Physical Dimensions 9.83 9.00 6.67 6.096 8.255 7.61 3.683 3.20 5.08 MAX 7.62 0.33 MIN 3.60 3.00 (0.56) 2.54 0.56 0.355 0.356 0.20 9.957 7.87 1.65 1.27 7.62 NOTES: UNLESS OTHERWISE SPECIFIED A) THIS PACKAGE CONFORMS TO JEDEC MS-001 VARIATION BA B) ALL DIMENSIONS ARE IN MILLIMETERS. C) DIMENSIONS ARE EXCLUSIVE OF BURRS, MOLD FLASH, AND TIE BAR EXTRUSIONS. D) DIMENSIONS AND TOLERANCES PER ASME Y14.5M-1994 E) DRAWING FILENAME AND REVSION: MKT-N08FREV2. Figure 24. 8-Lead, Dual Inline Package(DIP) Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/. © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.fairchildsemi.com 12 FSL136HR — Green Mode Fairchild Power Switch (FPS™) © 2011 Fairchild Semiconductor Corporation FSL136HR • Rev. 1.0.0 www.Fairchildsemi.com 13