FSL127H — Green Mode Fairchild Power Switch (FPS™)
September 2010
FSL127H Green Mode Fairchild Power Switch (FPS™)
Features
Built-in 5ms Soft-Start Function Internal Avalanche-Rugged 700V SenseFET Low Audio Noise High-Voltage Startup Fixed PWM Frequency at 100KHz Linearly Decreasing PWM Frequency to 18KHz Peak-Current-Mode Control Cycle-by-Cycle Current Limiting Leading-Edge Blanking (LEB) Synchronized Slope Compensation Internal Open-Loop Protection (OLP) VDD Under-Voltage Lockout (UVLO) VDD Over-Voltage Protection (OVP) Constant Power Limit (Full AC Input Range) Internal OTP Sensor with Hysteresis
Description
The highly integrated FSL127H consists of a current mode Pulse Width Modulator (PWM) and an avalancherugged 700V SenseFET. It is specifically designed for high-performance offline Switch Mode Power Supplies (SMPS) with minimal external components. The integrated PWM controller features include a proprietary green-mode function that provides off-time modulation to linearly decrease the switching frequency at light-load conditions to minimize standby power consumption. 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, the PWM controller is manufactured using the BiCMOS process, which allows an operating current of only 3.5mA. The FSL127H 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. The FSL127H provides many protection functions. In addition to cycle-by-cycle current limiting, the internal open-loop protection circuit ensures safety when an open-loop or output short-circuit failure occurs. PWM output is disabled until VDD drops below the UVLO lower limit, when the controller starts up again. As long as VDD exceeds ~28V, the internal OVP circuit is triggered. Compared to a discrete MOSFET and controller or RCC switching converter solution, the FSL127H reduces total component count, design size, and weight while increasing efficiency, productivity, and system reliability. These devices provide a basic platform well suited for design of cost-effective flyback converters.
Applications
General-purpose switch-mode power supplies and flyback power converters, including: SMPS for VCR, SVR, STB, DVD & VCD Player, Printer, Facsimile, & Scanner Adapter for Camcorder
Ordering Information
Part Number
FSL127HNY
SenseFET
2.0A 700V
Operating Temperature Range
-40°C to +105°C
Package
8-Pin Dual In-Line Package (MDIP), JEDEC MS-001, .300" Wide
Packing Method
Tube
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
www.fairchildsemi.com
FSL127H — Green Mode Fairchild Power Switch (FPS™)
Application Diagram
HV
Drain
VIN FB VDD GND
Figure 1. Typical Flyback Application
Output Power Table(1)
Product 230VAC ± 15% Adapter
(3) (2) (4)
85-265VAC Adapter
(3)
Open Frame
Open Frame
(4)
FSL127H 14W 20W 11W 16W Notes: 1. The maximum output power can be limited by junction temperature. 2. 230 VAC or 100/115 VAC with doublers. 3. Typical continuous power in a non-ventilated enclosed adapter with sufficient drain pattern as a heat sink, at TA=50°C ambient. 4. Maximum practical continuous power in an open-frame design with sufficient drain pattern as a heat sink, at TA=50°C ambient.
Internal Block Diagram
Figure 2. Internal Block Diagram
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2 www.fairchildsemi.com 2
FSL127H — Green Mode Fairchild Power Switch (FPS™)
Pin Configuration
F – Fairchild Logo Z – Plant Code X – 1-Digit Year Code Y – 1-Digit Week Code TT – 2-Digit Die Run Code T – Package Type (N: DIP) P – Y: Green Package M – Manufacture Flow Code
Figure 3. Pin Configuration
Pin Definitions
Pin #
1 2 3 4 5 6 7 8
Name
GND VDD FB VIN HV Drain Drain Drain
Description
Ground. SenseFET source terminal on primary side and internal control ground. Power Supply. The internal protection circuit disables PWM output as long as VDD exceeds the OVP trigger point. Feedback. 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. Line-Voltage Detection. The line-voltage detection is used for constant output power limit. It is suggested to add a low pass filter to filter out line ripple on bulk capacitor. Startup. For startup, this pin is pulled high to the line input or bulk capacitor via resistors. SenseFET Drain. High-voltage power SenseFET drain connection. SenseFET Drain. High-voltage power SenseFET drain connection. SenseFET Dain. High-voltage power SenseFET drain connection.
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
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
VDRAIN IDM EAS VVDD VFB VVIN VHV PD θJA Ψ JT TJ TSTG TL ESD Drain Pin Voltage
(5,6) (7)
Parameter
Drain Current Pulsed DC Supply Voltage FB Pin Input Voltage VIN Pin Input Voltage HV Pin Input Voltage Power Dissipation (TA<50°C) Junction-to-Air Thermal Resistance Junction-to-Top Thermal Resistance Operating Junction Temperature Storage Temperature Range Lead Temperature (Wave Soldering or IR, 10 Seconds) Electrostatic Discharge Capability, (10) All Pins Except HV Pin Human Body Model: JESD22-A114 Charged Device Model: JESD22-C101
(9)
Min.
Max.
700 8
Unit
V A mJ V V V V W °C/W °C/W °C °C °C kV
Single Pulsed Avalanche Energy
(8)
140 30 -0.3 -0.3 7.0 7.0 700 1.5 80 35 +150 -55 +150 +260 4.5 1.5
Notes: 5. All voltage values, except differential voltages, are given with respect to the network ground terminal. 6. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. 7. Non-repetitive rating: pulse width is limited by maximum junction temperature. 8. L = 51mH, starting TJ = 25°C. 9. Measured on the package top surface. 10. All pins including HV pin: HBM=500V, CDM=1250V.
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.
-40
Typ.
Max.
+105
Unit
°C
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics
VDD=15V and TA=25°C unless otherwise specified.
Symbol
SenseFET Section BVDSS
(11)
Parameter
Conditions
Min.
Typ.
Max.
Unit
Drain- Source Breakdown Voltage
VGS = 0V VDS = 700V, VGS = 0V
700 0.5 1 6.0 550 38 17 20 15 55 25 50.0
V
IDSS RDS(ON) CISS COSS CRSS td(on) tr td(off) tf VDD Section VOP VDD-ON VDD-OFF IDD-ST IDD-OP IDD-BM IDD-OLP VTH-OLP VDD-OVP tD-VDDOVP HV Section IHV IHV-LC
Zero-Gate-Voltage Drain Current Drain-Source On-State Resistance Input Capacitance Output Capacitance Reverse Transfer Capacitance Turn-On Delay Time Rise Time Turn-Off Delay Time Fall Time Continuously Operating Voltage Start Threshold Voltage Minimum Operating Voltage Startup Current Operating Supply Current Green-Mode Operating Supply Current Internal Sink Current IDD-OLP Off Voltage VDD Over-Voltage Protection VDD Over-Voltage Protection Debounce Time
(12)
VDS = 560V, VGS = 0V, TA = 125°C VGS = 10V, ID = 0.5A VGS = 0V, VDS = 25V, f = 1MHz VGS = 0V, VDS = 25V, f = 1MHz VGS = 0V, VDS = 25V, f = 1MHz VDS = 350V, ID = 1.0A VDS = 350V, ID = 1.0A VDS = 350V, ID = 1.0A VDS = 350V, ID = 1.0A
μA 200 7.2 715 50 26 50 40 120 60 22 11 7 12 8 3.5 2 30 5 27 75 60 6 28 130 90 7 29 200 13 9 30 3.0 4.0 Ω pF pF pF ns ns ns ns V V V µA mA mA µA V V µs
VDD-ON – 0.16V VDD = 15V, VFB = 3V VFB = VZDC VTH-OLP+0.1V
Maximum Current Drawn from HV Pin Leakage Current After Startup
HV 120VDC, VDD = 0V with 10µF HV = 700V, VDD = VDD-OFF+1V Center Frequency
1.5
3.5 1
5.0 20
mA
µA
Oscillator Section fOSC fOSC-G DMAX fDV fDT Frequency in Nominal Mode Green-Mode Frequency Maximum Duty Cycle Frequency Variation vs. VDD Deviation Frequency Variation vs. Temperature (11) Deviation VDD = 9V to 22V TA = -40 to +105°C 94 14 100 18 85 5 5 106 22 kHz kHz % % %
Continued on the following page…
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Electrical Characteristics (Continued)
VDD=15V and TA=25°C unless otherwise specified.
Symbol
VIN Section VIN-ON VIN-RL VIN-H tIN-H VIN-L AV ZFB VFB-OPEN VFB-OLP tD-OLP VFB-N VFB-G VFB-ZDC
Parameter
PWM Turn-on Threshold Voltage Release Latch Voltage Pull HIGH Latch Trigger Level Pull HIGH Latch Debounce Time Pull LOW Auto Recovery Trigger Level FB 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 FB Voltage
PWM Frequency fOSC
Conditions
Min.
0.98 0.60 4.4 0.2
Typ.
1.03 0.70 4.7 120 0.3 1/4.0 9.5
Max.
1.08 0.80 5.0 0.4
Unit
V V V µs V V/V kΩ V
Feedback Input Section
5 4.4 50 2.3 4.6 56 2.5 VFB-N 0.1 1.9 2.1 2.3 4.8 59 2.7
V ms V V V
fOSC-G
VFB-ZDC VFB-G
VFB-N
VFB
Figure 4. VFB vs. PWM Frequency
Symbol
Current-Sense Section ILIM at VIN = 1.2V ILIM at VIN = 3.6V tSS TOTP
Parameter
Peak Current Limit Peak Current Limit Period During Soft-Start Time
(11)
Conditions
VIN = 1.2V VIN = 3.6V
Min.
0.51 0.44 4.5
Typ.
0.61 0.54 5.0 142
Max.
0.71 0.64 5.5
Unit
A A ms °C
Over-Temperature Protection Section (OTP) Protection Junction Temperature
(11,13)
Notes: 11. These parameters, although guaranteed, are not 100% tested in production. 12. Pulse test: pulse width ≤ 300μs, duty ≤ 2%. 13. When activated, the output is disabled and the latch is turned off.
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics
Figure 5.
IDD-ST vs. Temperature
Figure 6.
IDD-OP vs. Temperature
Figure 7.
VDD-ON vs. Temperature
Figure 8.
VDD-OFF vs. Temperature
Figure 9.
VTH-OLP vs. Temperature
Figure 10. VDD-OVP vs. Temperature
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics
Figure 11. IHV vs. Temperature
Figure 12. fOSC vs. Temperature
Figure 13. fOSC-G vs. Temperature
Figure 14. VIN-ON vs. Temperature
Figure 15. VIN-RL vs. Temperature
Figure 16. VIN-H vs. Temperature
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Typical Characteristics
Figure 17. VIN-L vs. Temperature
Figure 18. VFB-N vs. Temperature
Figure 19. VFB-OLP vs. Temperature
Figure 20. tD-OLP vs. Temperature
Figure 21. VFB-ZDC vs. Temperature
Figure 22. IDD-BM vs. Temperature
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Functional Description
Startup Operation
For startup, the HV pin is connected to the line input or bulk capacitor through the external resistor RHV, as shown in Figure 23. Typical startup current drawn from the HV pin is 3.5mA and it charges the VDD capacitor through the resistor RHV. The startup current turns off when the VDD capacitor voltage reaches VDD-ON. The VDD capacitor maintains VDD until the auxiliary winding of the transformer provides the operating current.
Green-Mode Operation
The FSL127H uses feedback voltage (VFB) as an indicator of the output load and modulates the PWM frequency, as shown in Figure 25, such that the switching frequency decreases as load decreases. In heavy load conditions, the switching frequency is 100kHz. Once VFB decreases below VFB-N (2.5V), the PWM frequency starts to linearly decrease from 100kHz to 18kHz to reduce the switching losses. As VFB decreases below VFB-G (2.4V), the switching frequency is fixed at 18kHz and FSL127H enters “deep” green mode to reduce the standby power consumption. As VFB decreases below VFB-ZDC (2.1V), FSL127H enters burst-mode operation. When VFB drops below VFB-ZDC, FSL127H stops switching 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 to improve power saving, as shown in Figure 26.
R HV CDC
DDD HV VDD NA C DD FSL127H AC line
Figure 23. Startup Circuit
Slope Compensation
FSL127H is designed for flyback power converter. The peak-current-mode control is used to optimize system performance. Slope compensation is added to stabilize the current loop. The FSL127H inserts a synchronized, positively sloped ramp at each switching cycle.
Soft Start
The FSL127H has internal soft-start circuit that slowly increases the SenseFET current after startup. The typical soft-start time is 5ms, during which the VLimit level is increased in six steps to smoothly establish the required output voltage, as shown in Figure 24. It also helps prevent transformer saturation and reduces stress on the secondary diode during startup.
Figure 25. PWM Frequency
Figure 24. Soft-Start Function Figure 26. Burst Mode Operation
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Constant Power Control
To limit the output power of the converter constantly, high/low line compensation is included. Sensing the converter input voltage through the VIN pin, the high/low line compensation function generates a relative peak-current-limit threshold voltage for constant power control, as shown in Figure 27.
Figure 27. Constant Power Control
Protections
The FSL127H provides protection functions to prevent the power supply and the load from being damaged. The protection features include: Latch / Auto Recovery Function The FSL127H provides additional protections by the VIN pin, such as pull-HIGH latch and pull-LOW auto recovery that depend on the application. As shown in Figure 28, when VIN level is higher than 4.7V, FSL127H is latched until the VDD is discharged. FSL127H is in auto recovery when the VIN level is lower than 0.3V. Figure 29. OLP Operation 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 28V. It has a debounce time (typically 130µs) to prevent false trigger by switching noise. Over-Temperature Protection (OTP) The SenseFET and the control IC are integrated, making it easier to detect the temperature of the SenseFET. When the temperature exceeds approximately 142°C, thermal shutdown is activated.
Figure 28. VIN Pin Function Open-Loop / Overload Protection (OLP) W hen the upper branch of the voltage divider for the shunt regulator (KA431 shown) is broken, as shown in Figure 29, or over-current or output short occurs; there is no current flowing through the opto-coupler transistor, which pulls up the feedback voltage to 6V. When the feedback voltage is above 4.6V for 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.
© 2010 Fairchild Semiconductor Corporation FSL127H • Rev. 1.0.2
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FSL127H — Green Mode Fairchild Power Switch (FPS™)
Typical Application Circuit
Application
Adapter
Fairchild Devices
FSL127H
Input Voltage Range
90~264VAC
Output
12V/0.85A (10.2W)
Features
High efficiency (>76.74% at full load) meeting Energy Star V2.0 regulation with enough margin Standby power