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FPS

Design Guide

Fair

child 

Semiconductor

FPS

Fairchild’s Power Switch for

Switch Mode Power Supply

Design Guide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Summary of Contents for FPS FPS FSDM0565R

Page 1: ...www fairchildsemi com Building Block Solutions for Multi Market Applications FPS Design Guide Fairchild Semiconductor FPS Fairchild s Power Switch for Switch Mode Power Supply Design Guide ...

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Page 3: ...Isolated Flyback 16 2 5W Single Output Isolated Flyback Using FSD200 with KA431 Reference 17 10W Single Output Isolated Flyback Using FSDM0265R and Zener Diode 18 10W Multiple Output Isolated Flyback Using FSD210 with Primary Side Regulation 19 5W Buck Converter Using FSDL0165RN 20 16W Multiple Output Isolated Flyback Converter Using FSDM0265RN 21 180W 200W KA5Q1265RF Quasi resonant Flyback with I...

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Page 5: ...nd excessive voltage of controlled DC output These necessary protection features are combined with advanced control features such as burst mode operation for low standby power a precision oscillator with frequency modulation to minimize EMI and soft start Fairchild offers two design approaches 1 Parallel dice with SenseFET and PWM die side by side in one package 2 Single die monolithic design The ...

Page 6: ...illator Additional functions Startup circuit with soft start Frequency modulation Burst operation Protection function Over load protection Over voltage protection Over current protection Pulse by pulse current limit Over temperature protection AC Input Vo Softstart Frequency Setting Current Sensing MOSFET Drive PWM Controller Startup Resistor MOSFET UC3842 Comp Vref RtCt Isense Vfb Vcc Out GND FPS...

Page 7: ...st mode boards in white goods for example FSDL312 Built in startup Soft start Medium Power FSD1000 Auxiliary supplies PC main supply and PC auxiliary supply FPS with main power PWM integrated Burst mode Programmable soft start Internal startup FSDL0165RN Frequency modulation DVD player and auxiliary supply FSDH0265RN Built in startup DVD player FSDM0265RN Soft start Digital Still Camera DSC FSDL03...

Page 8: ...equency Synchronization Quasi Resonant Snubber Circuit Load Feedback Circuit Control IC FPS Advantages Low Standby Consumption with Burst Mode Operation Fully Avalanche Rugged 650V and 800V SenseFETs Improves Reliability Reduced EMI with Fully Integrated Frequency Modulation Reduces the Total Bill of Materials Cost with Integrated Protection and Control Functions Broad Application Coverage with Ex...

Page 9: ...feedback voltage to decrease When the feedback voltage goes below VBURSTL threshold switching stops in the FPS device saving considerable power Depending on load current the output voltages will eventually fall causing the feedback voltage to increase Once the feedback voltage crosses VBURSTH threshold switching starts again A 5V output FSD210 board at 265V in no load standby consumes a mere 92mW ...

Page 10: ...S devices modulate its frequency over a 4kHz frequency range EMI is thus spread over a wider range of frequencies Allows simple EMI filters to be employed for meeting world wide EMI requirements Refer to Application Note AN 4145 Electromagnetic Compatibility for Power Converters for additional information Below shows the frequency spectrum waveforms of a fixed frequency device versus a device that...

Page 11: ...hen feedback voltage continues to rise At 3V the feedback voltage is pulled up with a small internal 5µA current allowing for adjusting the delay as shown above When the feedback voltage crosses the over load shutdown VSD threshold the FPS stops switching With the FPS not switching bias current is not supplied to the FPS supply VCC storage capacitor When the VCC voltage reaches its under voltage l...

Page 12: ...start No No No FSD210 Internal Soft Start Yes Yes Needed Voltage Auto Restart Auto Restart No No Yes FSDM311 Internal Soft Start No Yes Needed Voltage Auto Restart Auto Restart No Auto Restart Yes FSD1000 Internal Soft Start No Yes Needed Current Voltage Auto Restart Auto Restart No Latch Yes FSDL0165RN Internal Soft Start Yes Yes Needed Current Auto Restart Auto Restart Auto Restart Auto Restart ...

Page 13: ...365RN DVDP STB VCR 24 0 28 0 2 2 650 4 5 50kHz DIP 8L FSDM0365RN DVDP STB VCR 24 0 28 0 2 2 650 4 5 67kHz DIP 8L KA5H0365R DVDP STB VCR 32 0 40 0 2 2 650 4 5 100kHz TO 220F 4L KA5H0380R DVDP STB VCR 32 0 40 0 2 2 800 5 100kHz TO 220F 4L KA5L0365R DVDP STB VCR 32 0 40 0 2 2 650 4 5 50kHz TO 220F 4L KA5L0380R DVDP STB VCR 32 0 40 0 2 2 800 5 50kHz TO 220F 4L KA5M0365R DVDP STB VCR 32 0 40 0 2 2 650 ...

Page 14: ...ons 80 250W Output Power Range 50 100W Output Power Range 10 50W Output Power Range 0 12W Output Power Range FSCQ0765RT FSCQ1265RT FSCQ1565RT FSD200 FSD210 FSDL312 FSD1000 FDSH321 FSDM311 FSDM0565R FSDM07652RB FSDH0265RN FSDL0165RN FSDL0365RN FSDM0365RN FSDM0265RN ...

Page 15: ...ly from the high voltage bus For output voltages of 12V and over the device may be powered directly from the output winding A low cost Zener diode circuit provides the regulation reference Less than 100mW standby power Ideal for applications permanently connected to an AC supply Overload protection circuit distinguishes between temporary and permanent overload Device does not shut down during load...

Page 16: ... flyback is used to generate voltages which are negative with respect to the neutral power line This is used in applications where triacs are driven such as in household appliances A Zener diode a bipolar transistor and a diode allow the negative voltage to be regulated by the FPS The dual input diode helps to protect against line transients Generation of two negative outputs referred to the input...

Page 17: ...tput accuracy is improved using the KA431 voltage reference The values R201 R203 C206 R204 and C104 set the closed loop control parameters and performance Using a Schottky diode is a cost effective method of improving efficiency where needed Feedback circuit using KA431 reference and H11A817A optocoupler More accurate regulation over line load and temperature than with a Zener diode Schottky diode...

Page 18: ... feedback circuit using a Zener diode R104 is used to reduce the current limit Higher power parts in the green FPS family have a higher current limit and a lower RDS on than the lower power parts Using a lower RDS on part increases the efficiency particularly at low input voltages So replacing a low power part with a high power part increases the efficiency but also the current limit If it were no...

Page 19: ...34kHz BZX84Cxx Zener Diodes 10V 12V P6KE200 Transient Voltage Suppressor 600W 200V SB140 Schottky Diode 1A 40V 1N4935 Fast Recovery Diode 1A 200V 1N4937 Fast Recovery Diode 1A 600V UF4007 Fast Recovery Diode 1A 1000V 1N4007 General Purpose Diode 1A 1000V 1N4148 General Purpose Diode 10mA 100V BC546B General Purpose Transistor 10W Multiple Output Isolated Flyback Using FSD210 with Primary Side Regu...

Page 20: ...to reduce the EMI caused by the switching Buck converter using FSDL0165 has high efficiency and low standby power Ideal replacement for 50Hz transformer solutions FSDL0165RN has a fully avalanche rated MOSFET Robust performance under transient conditions Current mode control maximizes operating flexibility Low component count for feedback control circuit Same circuit operates in DCM and CCM Curren...

Page 21: ...ng the size of the FPS device and the transformer The FSDM0265RN uses current mode control which provides excellent response to line and load transient conditions The flexible overload protection can distinguish between a temporary current surge and a longer term overload condition The over current latch is a current limit which is active even during the blanking time This provides additional syst...

Page 22: ...201 1000uF 50V L221 10uH 5A BEAD101 FERRITE BEAD BD100 R118 68K 0 5W R305 22K 0 6W D241 FYPF0545 T301 VOGT EF25 PFC D105 1N4937 D302 EGP30J C241 1000uF 50V VR301 10K D211 EGP20D R307 0 3R 0 6W R110 S10K275 CONN3 B2P VH C104 47nF 50V CONN1 B2P3 VH D231 EGP20K R105 470R 0 25W C111 630V C112 630V C221 1000uF 50V R201 1K 0 25W IC1 KA5Q1265RFYDTU F C400 CONN2 B9P VH C210 470pF 1000V C240 470pF 1000V D1...

Page 23: ...hich is typically supplied by a microcontroller is Low the current increases through the optocoupler the feedback voltage goes to ground and the device enters burst mode In this case the output voltages drop until the voltage supplied to the chip through the auxiliary winding drops to around 12V The device remains in hysteretic burst mode until the feedback voltage increases In this low power mode...

Page 24: ...uctance value is used to ensure that the associated leakage inductance is also kept low in this application remembering that snubber losses are proportional to the leakage inductance and to the square of the current FPS containing PWM IC with co packaged MOSFET solution is very robust and improves system reliability Fully avalanche rated switch Over current protection for secondary diode short cir...

Page 25: ...e is the additional L S pin which serves two functions First if the voltage drops below 2 55V the device stops switching If the voltage drops below 1 8V the device goes into a shutdown mode which consumes only 300µA in the Vcc line Flyback solution for this power level has good efficiency at a reasonable cost architecture can easily be expanded to support multiple outputs Dual function shut down p...

Page 26: ...d is to a 4 point increase in efficiency An auxiliary winding drives the MOSFET Also shown in Fairchild s FOD2741A which combines the optocoupler and reference functionality into one chip All relevant nodes are accessible LED drive reference drive and the reference voltage itself Implementation of Power over Ethernet with low component count Cost effective solution High efficiency further improved...

Page 27: ...ck design process Provides a lookup into a database of available devices Gives a first stab design for practical optimization Can be used with controllers other than FPS Application Notes and Demo Boards To download Application Notes and articles visit www fairchildsemi com fps Demoboards available for a wide range of applications Contact your local sales representative ...

Page 28: ...28 www fairchildsemi com fps FPS Design Guide Ordering Guide ...

Page 29: ...29 www fairchildsemi com fps FPS Design Guide Notes ...

Page 30: ...n Office 82 3 Dodang Dong Wonmi Ku Bucheon Gyounggi do 420 711 Korea Tel 82 32 680 1000 Fax 82 32 680 1949 Fairchild Korea Semiconductor Ltd Suwon Office Saemaeul hoi Building 1122 12 Ingye Dong Paldal gu Suwon si Gyunggi do 442 070 Korea Tel 82 31 231 3100 Fax 82 31 231 9846 Fairchild Korea Semiconductor Ltd Gumi Office 4F Saero net Building 274 9 Songjeong dong Gumi si Gyungsang buk Do 730 090 K...

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