FAN6862R / FAN6862L Highly Integrated Green-Mode PWM Controller Features Description Low Startup Current: 8µA PWM Frequency Continuously Decreasing with Burst Mode at Light Loads VDD Over-Voltage Protection (OVP) A highly integrated PWM controller, FAN6862R/L 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 continuously decrease the switching frequency under light-load conditions. Under zero-load conditions, the power supply enters burst mode, which completely shuts off PWM output. Output restarts just before the supply voltage drops below the UVLO lower limit. This green-mode function enables power supplies to meet international power conservation requirements. Feedback Open-Loop Protection with 56ms Delay Low Operating Current in Green Mode: 3mA Peak-Current-Mode Operation with Cycle-by-Cycle Current Limiting Constant Output Power Limit (Full AC Input Range) Over-Temperature Protection (OTP) Fixed PWM Frequency (65KHz) with Frequency Hopping Soft Start Time: 5ms 400mA Driving Capability Applications General-purpose switch-mode power supplies and flyback power converters, including: Power Adapters Open-Frame SMPS SMPS with Surge-Current Output, such as for Printers, Scanners, and Motor Drivers The FAN6862R/L is designed for SMPS and integrates a frequency-hopping function that helps reduce EMI emission of a power supply with minimum line filters. The built-in synchronized slope compensation is proprietary sawtooth compensation for constant output power limit over universal AC input range. The gate output is clamped at 18V to protect the external MOSFET from over-voltage damage. Other protection functions include VDD over-voltage protection, over-temperature protection, and overload protection. For over-temperature protection, an external NTC thermistor can be applied to sense the ambient temperature. When OVP, OTP, or OLP is activated, an internal protection circuit switches off the controller. Part Number OVP OTP OLP FAN6862RTY Auto Restart Auto Restart Auto Restart FAN6862LTY Latch Latch Latch Ordering Information Part Number Operating Temperature Range Eco Status Package Packing Method FAN6862RTY -40 to +105°C Green 6-Pin SSOT-6 Tape & Reel FAN6862LTY -40 to +105°C Green 6-Pin SSOT-6 Tape & Reel For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com FAN6862R/L — Highly Integrated Green-Mode PWM Controller January 2010 Figure 1. Typical Application Block Diagram FAN6862R/L — Highly Integrated Green-Mode PWM Controller Typical Application Figure 2. Block Diagram © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com 2 •••• ABxTT --- ABx: TT: yyyy: _ _ _: ABA: FAN6862LTY ABC: FAN6862RTY Wafer Lot Code Year Code Week Code Figure 3. Top Mark Pin Configuration Figure 4. Pin Assignments FAN6862R/L — Highly Integrated Green-Mode PWM Controller Marking Information Pin Definitions Pin # Name 1 GND Function Ground Feedback Description Ground The FB pin provides the output voltage regulation signal. It provides feedback to the internal PWM comparator for control of the duty cycle. This pin also provide for OLP: if VFB is larger than the trigger level and remains for a long time, the controller stops and restarts. 2 FB 3 RT 4 SENSE 5 VDD Power Supply Power supply 6 GATE Driver Output The totem-pole output driver for driving the power MOSFET. An external NTC thermistor is connected from this pin to GND for over-temperature Temperature protection. The impedance of the NTC decreases at high temperatures. Once the Detection voltage of the RT pin drops below a threshold, PWM output is disabled. Current Sense © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 This pin senses the voltage across a resistor. When the voltage reaches the internal threshold, PWM output is disabled. This activates over-current protection. This pin also provides current amplitude information for current-mode control. www.fairchildsemi.com 3 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 voltages, are given with respect to GND pin. Symbol Parameter VDD Supply Voltage VL Input Voltage to FB, SENSE, RT Pin PD Power Dissipation at TA<50°C ΘJC TJ TSTG TL ESD Min. Max. Unit 30 V -0.3 7.0 V 300 mW 115 °C/W Operating Junction Temperature Thermal Resistance (Junction-to-Case) -40 +150 °C Storage Temperature Range -55 +150 °C Lead Temperature, Wave Soldering, 10 Seconds +260 °C Human Body Model, JESD22-A114 3.00 Charge Device Model, JESD22-C101 1.25 kV 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 © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 Min. Max. Unit -40 +105 °C FAN6862R/L — Highly Integrated Green-Mode PWM Controller Absolute Maximum Ratings www.fairchildsemi.com 4 VDD = 15V and TA = 25°C unless otherwise noted. Symbol Parameter Test Condition Min. Typ. Max. Unit VDD Section VDD-OP Continuously Operating Voltage 24 V VDD-ON Turn-On Threshold Voltage 15 16 17 V VDD-OFF Turn-Off Voltage 7.5 8.5 9.5 V VDD-OVP VDD Over-Voltage Protection (Latch-Off) 24 25 26 V VDD-LH Threshold Voltage for Latch-Off Release 3 4 5 V IDD-ST Startup Current VDD-ON–0.16V 8 30 μA IDD-OP Normal Operating Supply Current CL=1nF 3 4 mA IDD-BM Green-Mode Operating Supply Current GATE Open, VFB=VFB-G 2.5 mA VDD-OVP VDD Over-Voltage Protection tD-VDDOVP VDD OVP Debounce Time IDD-LH Latch-Off Holding Current 24 VDD=5V 25 26 V 30 50 μs 40 65 μA 1/3.5 1/3.0 V/V Feedback Input Section AV Input-Voltage to Current-Sense Attenuation ZFB Input Impedance 1/4.0 5.5 kΩ VFB-OPEN FB Pin Open Voltage 5.0 5.2 5.4 V VFB-OLP Threshold Voltage for Open-Loop Protection 4.3 4.6 4.9 V Open-Loop Protection Delay Time 53 56 60 ms 100 250 ns tD-OLP Current Sense Section tPD tLEB Delay to Output 360 ns VSTHFL Flat Threshold Voltage for Current Limit Duty>51% 0.5 V VSTHVA Valley Threshold Voltage for Current Limit Duty=0% 0.44 V VSLOPE Slope Compensation Duty=DCYMAX 0.273 V 5 ms tSOFT-START Leading-Edge Blanking Time 270 Period During Startup Time FAN6862R/L — Highly Integrated Green-Mode PWM Controller Electrical Characteristics Oscillator Section Center Frequency fOSC VFB>VFB-N 62 65 Normal PWM Frequency Hopping Range VFB≥VFB-N ±4.2 Hopping Range VFB=VFB-G ±2.9 68 kHz thop-1 Hopping Period 1 VFB≥VFB-N 4.4 ms thop-3 Hopping Period 3 VFB=VFB-G 11.5 ms fOSC-G Green Mode Minimum Frequency 22.5 kHz VFB-N FB Threshold Voltage For Frequency Reduction 2.5 V VFB-G FB Voltage at fOSC-G 2.1 V VFB-ZDC FB Threshold Voltage for Zero Duty 1.7 fDV Frequency Variation vs. VDD Deviation VDD=11.5V to 20V fDT Frequency Variation vs. Temperature Deviation TA= -40 to +105°C 0 0.02 V 2.00 % 2 % Continued on the following page… © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com 5 VDD = 15V and TA = 25°C unless otherwise noted. Symbol Parameter Test Condition Min. Typ. Max. Unit PWM Output Section DCYMAX Maximum Duty Cycle 70 VOL Output Voltage Low VDD=15V, IO=50mA VOH Output Voltage High VDD=8V, IO=50mA tR Rising Time CL=1nF 150 tF Falling Time CL=1nF 35 Gate Output Clamping Voltage VDD=20V VCLAMP % 1.5 6 15.0 V V 16.5 200 ns ns 18.0 V Over-Temperature Protection (OTP) Section IRT Output Current of RT Pin VOTP Threshold Voltage for Over-Temperature Protection tDOTP Over-Temperature Debounce Time VOTP2 2 Threshold Voltage for OverTemperature Protection tDOTP2 2 100 TA=25°C 0.97 1.02 VFB=VFB-N 17 VFB=VFB-G 51 μA 1.07 V ms nd nd TA=25°C Over-Temperature Debounce Time © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 0.60 0.70 100 0.75 V μs FAN6862R/L — Highly Integrated Green-Mode PWM Controller Electrical Characteristics (Continued) www.fairchildsemi.com 6 9.5 16.6 9.1 VDD-OFF (V) VDD-ON (V) 17 16.2 15.8 8.7 8.3 7.9 15.4 7.5 15 -40 -30 -15 0 25 50 75 85 100 125 -40 -30 -15 0 Turn-On Threshold Voltage (VDD-ON) vs. Temperature Figure 6. 4.5 26 4.1 25.6 VDD-OVP (V) IDD-OP (mA) Figure 5. 3.7 3.3 2.9 50 75 85 100 125 Turn-Off Threshold Voltage (VDD-OFF) vs. Temperature 25.2 24.8 24.4 2.5 24 -40 -30 -15 0 25 50 75 85 100 125 -40 -30 -15 0 Temperature (ºC) Figure 7. 25 50 75 85 100 125 Temperature (ºC) Operating Current (IDD-OP) vs. Temperature Figure 8. 68 VDD Over-Voltage Protection (VDD-OVP) vs. Temperature 2.7 67 2.6 66 VFB-N (V) fOSC (KHz) 25 Temperature (ºC) Temperature (ºC) FAN6862R/L — Highly Integrated Green-Mode PWM Controller Typical Performance Characteristics 65 2.5 2.4 64 2.3 63 2.2 62 -40 -30 -15 0 25 50 75 85 100 -40 125 Figure 9. Center Frequency (fOSC) vs. Temperature © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 -30 -15 0 25 50 75 85 100 125 Temperature (ºC) Temperature (ºC) Figure 10. FB Threshold Voltage for Frequency Reduction (VFB-N) vs. Temperature www.fairchildsemi.com 7 2.3 4.9 4.8 VFB-OLP (V) VFB-G (V) 2.2 2.1 2 1.9 4.7 4.6 4.5 4.4 1.8 4.3 -40 -30 -15 0 25 50 75 85 100 125 -40 -30 -15 0 Temperature (ºC) Figure 11. FB Voltage at fOSC-G (VFB-G) vs. Temperature 75 85 100 125 0.6 58 0.56 57 VSTHFL (V) tD-OLP (mS) 50 Figure 12. Threshold Voltage for Open-Loop Protection (VFB-OLP) vs. Temperature 59 56 55 0.52 0.48 0.44 54 53 0.4 -40 -30 -15 0 25 50 75 85 100 125 -40 -30 -15 0 Temperature (ºC) 25 50 75 85 100 125 Temperature (ºC) Figure 13. Open-Loop Protection Delay Time (tD-OLP) vs. Temperature Figure 14. Flat Threshold Voltage for Current Limit (VSTHFL) vs. Temperature 0.55 7 0.51 6 tSOFT-START (mS) VSTHVA (V) 25 Temperature (ºC) FAN6862R/L — Highly Integrated Green-Mode PWM Controller Typical Performance Characteristics (Continued) 0.47 0.43 5 4 3 0.39 2 0.35 -40 -30 -15 0 25 50 75 85 100 -40 125 Figure 15. Valley Threshold Voltage for Current Limit (VSTHVA) vs. Temperature © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 -30 -15 0 25 50 75 85 100 125 Temperature (ºC) Temperature (ºC) Figure 16. Period during Startup (tSOFT-START) vs. Temperature www.fairchildsemi.com 8 180 71 160 70 140 tR (nS) DCYMAX (%) 72 69 68 120 100 67 80 -40 -30 -15 0 25 50 75 85 100 125 -40 -30 -15 Temperature (ºC) 25 50 75 85 100 125 Temperature (ºC) Figure 17. Maximum Duty Cycle (DCYMAX) vs. Temperature Figure 18. Rising Time (tR) vs. Temperature 70 120 60 112 50 104 IRT (μA) tF (nS) 0 40 30 96 88 20 FAN6862R/L — Highly Integrated Green-Mode PWM Controller Typical Performance Characteristics (Continued) 80 -40 -30 -15 0 25 50 75 85 100 125 -40 Temperature (ºC) -15 0 25 50 75 85 100 125 Temperature (ºC) Figure 19. Falling Time (tF) vs. Temperature © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 -30 Figure 20. Output Current of RT Pin (IRT) vs. Temperature www.fairchildsemi.com 9 Frequency Startup Operation Figure 21 shows a typical startup circuit and transformer auxiliary winding for a typical application. Before FAN6862R/L begins switching operation, it consumes only startup current (typically 8μA) and the current supplied through the startup resistor charges the VDD capacitor (CDD). When VDD reaches the turn-on voltage of 16V (VDD-ON), FAN6862R/L begins switching and the current consumed increases to 3mA. Then the power required is supplied from the transformer auxiliary winding. The large hysteresis of VDD (8.5V) provides more holdup time, which allows using a small capacitor for VDD. The startup resistor is typically connected to AC line for a fast reset of latch protection. PWM Frequency +4.2kHz 65kHz -4.2kHz +2.9kHz 22.5kHz -2.9kHz VFB-ZDC VFB -G VFB -N VFB Figure 22. PWM Frequency Vo VFB VFB.ZDC (1.7V) Ids Switching Disabled Figure 21. Startup Circuit FAN6862R/L — Highly Integrated Green-Mode PWM Controller Operation Description Switching Disabled Figure 23. Burst-Mode Operation Frequency Hopping Green-Mode Operation EMI reduction is accomplished by frequency hopping, which spreads the energy over a wider frequency range than the bandwidth measured by the EMI test equipment. An internal frequency hopping circuit changes the switching frequency between 60.8kHz and 69.2kHz with a period of 4.4ms, as shown in Figure 24. The FAN6862R/L uses feedback voltage (VFB) as an indicator of the output load and modulates the PWM frequency, as shown in Figure 22, such that the switching frequency decreases as load decreases. In heavy-load conditions, the switching frequency is 65KHz. Once VFB decreases below VFB-N (2.5V), the PWM frequency starts to linearly decrease from 65KHz to 22.5kHz to reduce the switching losses. As VFB decreases below VFB-G (2.1V), the switching frequency is fixed at 22.5kHz and FAN6862R/L enters “deep” green mode, where the operating current decreases to 2.5mA (maximum), further reducing the standby power consumption. As VFB decreases below VFB-ZDC (1.7V), FAN6862R/L enters burst-mode operation. When VFB drops below VFB-ZDC, switching stops and the output voltage starts to drop, which causes the feedback voltage to rise. Once VFB rises above VFB-ZDC, switching resumes. Burst mode alternately enables and disables switching, thereby reducing switching loss in standby mode, as shown in Figure 23. © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 Figure 24. Frequency Hopping www.fairchildsemi.com 10 Open-Loop / Overload Protection (OLP) When the upper branch of the voltage divider for the shunt regulator (KA431 shown) is broken, as shown in Figure 26, no current flows through the opto-coupler transistor, which pulls up the feedback voltage to 5.2V. Self-protective functions include VDD Over-Voltage Protection (OVP), Open-Loop / Overload Protection (OLP), Over-Current Protection (OCP), Short-Circuit Protection, and Over-Temperature Protection (OTP). FAN6862R uses auto-restart mode protections and FAN6862L uses latch-mode protections. When the feedback voltage is above 4.6V longer than 56ms, OLP is triggered. This protection is also triggered when the SMPS output drops below the nominal value longer than 56ms due to the overload condition. Auto-Restart Mode Protection: Once a fault condition is detected, switching is terminated and the MOSFET remains off. This causes VDD to fall because no more power is delivered from auxiliary winding. When VDD falls to VDD-OFF (8.5V), the protection is reset and the operating current reduces to startup current, which causes VDD to rise. FAN6862R resumes normal operation when VDD reaches VDD-ON (16V). In this manner, the auto-restart can alternately enable and disable the switching of the MOSFET until the fault condition is eliminated (see Figure 25). Latch-Mode Protection: Once this protection is triggered, switching is terminated and the MOSFET remains off. The latch is reset only when VDD is discharged below 4V by unplugging AC power line. VDS Protection Triggers Power On Fault Removed VFB 5.2V VFB-OLP (4.6V) VDD OLP Shutdown Delay Time FAN6862R/L — Highly Integrated Green-Mode PWM Controller Protections OLP Triggers Figure 26. OLP Operation 16V VDD Over-Voltage Protection (OVP) VDD over-voltage protection prevents IC damage caused by over voltage on the VDD pin. The OVP is triggered when VDD reaches 25V. A debounce time (typically 30µs) prevents false triggering by switching noise. 8.5V Operating Current 3mA Over-Temperature Protection (OTP) The OTP circuit is composed of current source and voltage comparators. Typically, an NTC thermistor is connected between the RT and GND pins. Once the voltage of this pin drops below a threshold of 1.02V, PWM output is disabled after tDOTP debounce time. If this pin drops below 0.7V, it triggers the latch-off protection immediately after tDOTP2 debounce time. 8uA Normal Operation Fault Situation Normal Operation Figure 25. Auto-Restart Operation Over-Current Protection (OCP) FAN6862R/L has over-current protection thresholds. It is for pulse-by-pulse current limit, which turns off the MOSFET for the remainder of the switching cycle when the sensing voltage of MOSFET drain current reaches the threshold. The other threshold is for the over-current protection, which shuts down the MOSFET gate when the sensing voltage of MOSFET drain current is above the threshold longer than the shutdown delay (56ms). © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com 11 Leading-Edge Blanking (tLEB) FAN6862R/L has saw-limiter for pulse-by-pulse current limit, which guarantees almost constant power limit over different line voltages of universal input range. Each time the power MOSFET is switched on, a turn-on spike occurs across the sense-resistor caused by primary-side capacitance and secondary-side rectifier reverse recovery. To avoid premature termination of the switching pulse, a leading-edge blanking time is built in. During this blanking period (360ns), the PWM comparator is disabled and cannot switch off the gate driver. Thus, RC filter with a small RC time constant is enough for current sensing. The conventional pulse-by-pulse current limiting scheme has a constant threshold for current limit comparator, which results in a higher power limit for high line voltage. FAN6862R/L has a sawtooth current limit threshold that increases progressively within a switching cycle, which provides lower current limit for high line and makes the actual power limit level almost constant over different line voltages of universal input range, as shown in Figure 27. Figure 28. Current Sense R-C Filter Soft-Start Figure 27. Sawtooth Current Limiter © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 FAN6862R/L — Highly Integrated Green-Mode PWM Controller Constant Output Power Limit The FAN6862R/L has an internal soft-start circuit that increases pulse-by-pulse current-limit comparator inverting input voltage slowly after it starts. The typical soft-start time is 5ms. The pulsewidth to the power MOSFET is progressively increased to establish the correct working conditions for transformers, rectifier diodes, and capacitors. The voltage on the output capacitors is progressively increased with the intention of smoothly establishing the required output voltage. It also helps prevent transformer saturation and reduces the stress on the secondary diode during startup. www.fairchildsemi.com 12 Application Fairchild Devices Input Voltage Range Output Netbook Adapter FAN6862R/L 90~265VAC 19V/2.1A (40W) Features High efficiency (>85.3% at full load) meeting EPS regulation with enough margin Low standby (Pin<0.15W at no-load condition) Soft-start time: 5ms Efficiency (%) 91 90 89 88 5 115VAC 60Hz (89.15% avg) 4.5 3.5 87 86 85 84 3 2.5 85.29% (Energy star V2.0) 2 83 1.5 82 25% Over Current Protection 4 230VAC 50Hz (89.47% avg) Io(A) 1 50% Load (%) 75% 100% 90V 115V Vac(V) 230V 264V FAN6862R/L — Highly Integrated Green-Mode PWM Controller Typical Application Circuit (Netbook Adapter by Flyback) Figure 29. Measured Efficiency and Over-Current Protection Figure 30. Schematic of Typical Application Circuit © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com 13 Transformer Specification Core: RM 8 Bobbin: RM 8 Figure 31. Transformer Diagram NO N1 N2 Terminal S F 11 10 3 2 Fly2 0.25*1 INSULATION BARRIER Ts Primary Secondary 9 3 - - 0.25* 1 33 1 - - 1.2 3 - - 0.5* 2 12 1 - - COPPER SHIELD 1.2 3 - - 0.25 * 1 33 4 - - CORE ROUNDING TAPE - 3 Fly+ 11 N4 Ts COPPER SHIELD 11 N3 WIRE 1 Pin Specification Remark Primary-Side Inductance 3－1 920µH ± 5% 100kHz, 1V Primary-Side Effective Leakage 3－1 15µH maximum Short one of the secondary windings © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 FAN6862R/L — Highly Integrated Green-Mode PWM Controller Typical Application Circuit (Continued) www.fairchildsemi.com 14 FAN6862R/L — Highly Integrated Green-Mode PWM Controller Physical Dimensions Figure 32. 6-Pin, SUPERSOT6 “SSOT-6”, JEDEC MO-193, 1.6mm Wide Package 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/. © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com 15 FAN6862R/L — Highly Integrated Green-Mode PWM Controller © 2009 Fairchild Semiconductor Corporation FAN6862R/L • Rev. 1.0.0 www.fairchildsemi.com 16