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august 2011 ? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 fsq0365/0265/0165/321 ? green mode fairchild power switch (fps?) for valley switching converter fsq0365, FSQ0265, fsq0165, fsq321 green mode fairchild power switch (fps?) for valley switching converter ? low emi and high efficiency features ? optimized for valley switching converter (vsc) ? low emi through variable frequency control and inherent frequency modulation ? high efficiency through minimum voltage switching ? narrow frequency variation range over wide load and input voltage variation ? advanced burst-mode oper ation for low standby power consumption ? pulse-by-pulse current limit ? protection functions: over load protection (olp), over-voltage protection (ovp), abnormal over- current protection (aocp), internal thermal shutdown (tsd) ? under-voltage lockout (uvlo) with hysteresis ? internal startup circuit ? internal high-voltage sensefet: 650v ? built-in soft-start: 15ms applications ? power supplies for dvp player, dvd recorder, set-top box ? adapter ? auxiliary power supply for pc, lcd tv, and pdp tv description a valley switching converter 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 valley switching operation with minimal external components. the pwm controller includes an in tegrated fixed-frequency oscillator, under-voltage lockout, leading-edge blanking (leb), optimized gate driver, internal soft-start, temperature-compensated prec ise current sources for loop compensation, and self-protection circuitry. compared with discrete mosfet and pwm controller solutions, the fsq-series reduces total cost, component count, size and weight; while simultaneously increasing efficiency, productivity, and system reliability. this device provides a basic platform for cost-effective designs of valley switching fly-back converters. related application notes ? an-4137 - design guidelines for offline flyback converters using fairchild power switch (fps?) ? an-4141 - troubleshooting and design tips for fairchild power switch (fps?) flyback applications ? an-4147 - design guidelines for rcd snubber of flyback converters ? an-4150 - design guidelines for flyback converters using fsq-series fairchild power switch (fps?) ? an-4134 - design guidelines for off-line forward converters using fairchild power switch (fps?)
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 2 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter ordering information part number package operating temperature current limit r ds(on) (max.) maximum output table (1) replaces devices 230v ac 15% (2) 85-265v ac adapter (3) open frame (4) adapter (3) open frame (4) fsq321 8-dip -40 to +85c 0.6a 19 ? 8w 12w 7w 10w fsdl321 fsdm311 fsq321l 8-lsop fsq321lx 8-lsop (tape & reel) fsq0165rn 8-dip -40 to +85c 0.9a 10 ? 10w 15w 9w 13w fsdl0165rn fsq0165rl 8-lsop fsq0165rlx 8-lsop (tape & reel) FSQ0265rn 8-dip -40 to +85c 1.2a 6 ? 14w 20w 11w 16w fsdm0265rn fsdm0265rnb FSQ0265rl 8-lsop fsq0365rn 8-dip -40 to +85c 1.5a 4.5 ? 17.5w 25w 13w 19w fsdm0365rn fsdm0365rnb fsq0365rl 8-lsop notes: 1. the junction temperature can limit the maximum output power. 2. 230v ac or 100/115v ac with voltage doubler. the maximum power with ccm operation 3. typical continuous power in a non-v entilated, enclosed adapt er measured at 50 ? c ambient temperature. 4. maximum practical continuous power in an open-frame design at 50 ? c ambient temperature.
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 3 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter application circuit v cc gnd drain sync vo pwm v fb ac in v str figure 1. typical flyback application internal block diagram 8v/12v v ref s q q r v cc v ref i delay i fb v sd v ovp sync v ocp s q q r r 3r v cc good vcc drain vfb gnd aocp gate driver v cc good leb 200ns pwm v burst 4 sync + - + - 0.7v/0.2v 2.5 s time delay (1.1v) soft- start 6v 6v 0.35/0.55 + - osc vstr tsd 3 2 8 7 6 5 fsq0365rn rev.00 1 figure 2. internal block diagram
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 4 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter pin assignments figure 3. pin configuration (top view) pin definitions pin# name description 1 gnd sensefet source terminal on pr imary side and internal control ground. 2 v cc positive supply voltage input. although connec ted to an auxiliary transformer winding, current is supplied from pin 5 (vstr) via an internal switch during startup (see figure 2) . it is not until v cc reaches the uvlo upper threshold (12v ) that the internal startup switch opens and device power is supplied vi a the auxiliary transformer winding. 3 vfb the feedback voltage pin is the non-inverting input to the pwm comparator. it has a 0.9ma current source connected internally wh ile a capacitor and opto-coupler are typically connected externally. there is a time del ay while charging external capacitor c fb from 3v to 6v using an internal 5 ? a current source. this delay prevents false triggering under transient conditions, but still allows the protection mechanism to operate under true overload conditions. 4 sync this pin is internally connected to the sy nc-detect comparator for valley switching. typically the voltage of the auxiliary winding is used as sync input voltage and external resistors and capacitor are needed to make delay to match valley point. the threshold of the internal sync comparator is 0.7v/0.2v. 5 vstr this pin is connected to the rectified ac line vo ltage source. at startup, the internal switch supplies internal bias and charges an exter nal storage capacitor placed between the vcc pin and ground. once the v cc reaches 12v, the internal switch is opened. 6, 7, 8 drain the drain pins are designed to connect directly to the primary lead of the transformer and are capable of switching a maximum of 650v. minimizing the length of the trace connecting these pins to the transfo rmer decreases leakage inductance.
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 5 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter absolute maximum ratings stresses exceeding the absolute maximum ratings may damage the device. the devic e may not function or be operable above the recommended operating c onditions and stressing the parts to these levels is not recommended. in addition, extended exposure to stre sses above the recommended operating conditi ons may affect device reliability. the absolute maximum ratings are stress ratings only. t a =25c, unless otherwise specified. symbol parameter min. max. unit v str vstr pin voltage 500 v v ds drain pin voltage 650 v v cc supply voltage 20 v v fb feedback voltage range -0.3 9.0 v v sync sync pin voltage -0.3 9.0 v i dm drain current pulsed (6) fsq0365 12.0 a FSQ0265 8.0 fsq0165 4.0 fsq321 1.5 e as single pulsed avalanche energy (7) fsq0365 230 mj FSQ0265 140 fsq0165 50 fsq321 10 p d total power dissipation 1.5 w t j recommended operating junction temper ature -40 internally limited ? c t a operating ambient temperature -40 +85 ? c t stg storage temperature -55 +150 ? c esd human body model; jesd22-a114 class 1c machine model; jesd22-a115 class b notes: 5. repetitive rating: puls e width limited by maximu m junction temperature. 6. l=51mh, starting t j =25c. thermal impedance symbol parameter value unit 8-dip (7) ja junction-to-ambient thermal resistance (8) 80 c/w jc junction-to-case thermal resistance (9) 20 jt junction-to-top thermal resistance (10) 35 notes: 7. all items are tested with the standards jesd 51-2 and 51-10 (dip). 8. free-standing with no heat-sin k, under natural convection. 9. infinite cooling condition - refer to the semi g30-88. 10. measured on the pa ckage top surface.
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 6 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter electrical characteristics t a =25 ? c unless otherwise specified. symbol parameter condition min. typ. max. unit sensefet section bv dss drain-source breakdown voltage v cc =0v, i d =100a 650 v i dss zero-gate-voltage drain current v ds =650v 100 a r ds(on) drain-source on- state resistance (11) fsq0365 t j =25 ? c, i d =0.5a 3.5 4.5 ?? FSQ0265 5.0 6.0 fsq0165 8.0 10.0 fsq321 14.0 19.0 c iss input capacitance fsq0365 v gs =0v, v ds =25v, f=1mhz 315 pf FSQ0265 550 fsq0165 250 fsq321 162 c oss output capacitance fsq0365 v gs =0v, v ds =25v, f=1mhz 47 pf FSQ0265 38 fsq0165 25 fsq321 18 c rss reverse transfer capacitance fsq0365 v gs =0v, v ds =25v, f=1mhz 9.0 pf FSQ0265 17.0 fsq0165 10.0 fsq321 3.8 t d(on) turn-on delay fsq0365 v dd =350v, i d =25ma 11.2 ns FSQ0265 20.0 fsq0165 12.0 fsq321 9.5 t r rise time fsq0365 v dd =350v, i d =25ma 34 ns FSQ0265 15 fsq0165 4 fsq321 19 t d(off) turn-off delay fsq0365 v dd =350v, i d =25ma 28.2 ns FSQ0265 55.0 fsq0165 30.0 fsq321 33.0 t f fall time fsq0365 v dd =350v, i d =25ma 32 ns FSQ0265 25 fsq0165 10 fsq321 42 burst-mode section v burh burst-mode voltage t j =25c, t pd =200ns (12) 0.45 0.55 0.65 v v burl 0.25 0.35 0.45 v v bur(hys) 200 mv continued on the following page?
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 7 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter electrical characteristics (continued) t a =25 ? c unless otherwise specified. symbol parameter conditions min. typ. max. unit control section t on.max1 maximum on time1 all but fsq321 t j =25c 10.5 12.0 13.5 s t on.max2 maximum on time2 fsq321 t j =25c 6.35 7.06 7.77 s t b1 blanking time1 all but fsq321 13.2 15.0 16.8 s t b2 blanking time2 fsq321 7.5 8.2 s t w detection time window t j =25c, v sync =0v 3.0 s ? f s switching frequency variation (14) -25 ? c < t j < 85 ? c 5 10 % i fb feedback source current v fb =0v 700 900 1100 a d min minimum duty cycle v fb =0v 0 % v start uvlo threshold voltage after turn-on 11 12 13 v v stop 7 8 9 v t s/s1 internal soft-start time 1 all but fsq321 with free-running frequency 15 ms t s/s2 internal soft-start time 2 fsq321 with free-running frequency 10 ms protection section i lim peak current limit fsq0365 t j =25c, di/dt=240ma/ s 1.32 1.50 1.68 a FSQ0265 t j =25c, di/dt=200ma/ s 1.06 1.20 1.34 fsq0165 t j =25c, di/dt=175ma/s 0.8 0.9 1.0 fsq321 t j =25c, di/dt=125ma/ s 0.53 0.60 0.67 v sd shutdown feedback voltage v cc =15v 5.5 6.0 6.5 v i delay shutdown delay current v fb =5v 4.0 5.0 6.0 a t leb leading-edge blanking time (13) 200 ns v ovp over-voltage protection v cc =15v, v fb =2v 5.5 6.0 6.5 v t ovp over-voltage protection blanking time 2 3 4 s t sd thermal shutdown temperature (13) 125 140 155 c sync section v sh sync threshold voltage 0.55 0.70 0.85 v v sl 0.14 0.20 0.26 v t sync sync delay time (13,14) 300 ns total device section i op operating supply current (control part only) v cc =15v 1 3 5 ma i start start current v cc =v start - 0.1v (before v cc reaches v start ) 270 360 450 a i ch startup charging current v cc =0v, v str =minimum 40v 0.65 0.85 1.00 ma v str minimum v str supply voltage 26 v notes: 11. pulse test: pulse-width=300 ? s, duty=2%. 12. propagation delay in the control ic. 13. though guaranteed, it is not 100% tested in production. 14. includes gate turn-on time.
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 8 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter comparison between fsdm0x65rnb and fsq-series function fsdm0x65rnb fsq-series advantages of fsq-series operation method constant frequency pwm valley switching operation ? improved efficiency by valley switching ? reduced emi noise emi reduction frequency modulation valley switching & inherent frequency modulation ? reduce emi noise in two ways burst-mode operation fixed burst peak advanced burst- mode ? improved standby power by valley switching also in burst-mode ? because the current peak during burst operation is dependent on v fb , it is easier to solve audible noise protection aocp ? improved reliability through precise abnormal over- current protection
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 9 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter typical performance characteristics characteristic graphs are normalized at t a =25c. -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 4. operating supply current (i op ) vs. t a figure 5. uvlo start threshold voltage (v start ) vs. t a -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 6. uvlo stop threshold voltage (v stop ) vs. t a figure 7. startup charging current (i ch ) vs. t a -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 8. initial switching frequency (f s ) vs. t a figure 9. maximum on time (t on.max ) vs. t a
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 10 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter typical performance characteristics (continued) characteristic graphs are normalized at t a =25c. -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 10. blanking time (t b ) vs. t a figure 11. feedback source current (i fb ) vs. t a -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 12. shutdown delay current (i delay ) vs. t a figure 13. burst mode high threshold voltage (v burh ) vs. t a -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 14. burst mode low threshold voltage (v burl ) vs. t a figure 15. peak current limit (i lim ) vs. t a
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 11 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter typical performance characteristics (continued) characteristic graphs are normalized at t a =25c. -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 16. sync high threshold (v sh ) vs. t a figure 17. sync low threshold voltage (v sl ) vs. t a -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] -25 0 25 50 75 100 125 0.0 0.2 0.4 0.6 0.8 1.0 1.2 normalized temperature [c] figure 18. shutdown feedback voltage (v sd ) vs. t a figure 19. over-voltage protection (v op ) vs. t a
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 12 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter functional description 1. startup : at startup, an inter nal high-voltage current source supplies the inter nal bias and charges the external capacitor (c a ) connected to the v cc pin, as illustrated in figure 20. when v cc reaches 12v, the fps? begins switching and the internal high-voltage current source is disabl ed. the fps continues its normal switching operation and the power is supplied from the auxiliary transformer winding unless v cc goes below the stop voltage of 8v. 8v/12v v ref internal bias v cc v str i ch v cc good v dc c a fsq0365rn rev.00 2 5 figure 20. startup circuit 2. feedback control : fps employs current mode control, as shown in figure 21. an opto-coupler (such as fod817a) and shunt regulator (such as ka431) are often used to implement the feedback network. comparing the feedback volt age with the voltage across the r sense resistor makes it possible to control the switching duty cycle. when t he reference pin voltage of the shunt regulator exceeds the internal reference voltage of 2.5v, t he opto-coupler led current increases, pulling down the feedback vo ltage and reducing the duty cycle. this event typically occurs when input voltage is increased or output load is decreased. 2.1 pulse-by-pulse current limit : because current mode control is employed, the peak current through the sensefet is limited by t he inverting input of pwm comparator (v fb *), as shown in figure 21. assuming that the 0.9ma current s ource flows only through the internal resistor (3r + r = 2.8k ? ), the cathode voltage of diode d2 is about 2.5v. si nce d1 is blocked when the feedback voltage (v fb ) exceeds 2.5v, the maximum voltage of the cathode of d2 is clamped at this voltage, clamping v fb *. therefore, the peak value of the current through the sensefet is limited. 2.2 leading-edge blanking (leb) : at the instant the internal sensefet is tur ned on, a high-current spike usually occurs through the sensefet, caused by primary-side capacitance and secondary-side rectifier reverse recovery. excessi ve voltage across the r sense resistor would lead to inco rrect feedback operation in the current mode pwm control. to counter this effect, the fps employs a leading-edge blanking (leb) circuit. this circuit inhibits the pwm comparator for a short time (t leb ) after the sensefet is turned on. 3 osc v cc v ref i delay i fb v sd r 3r gate driver olp d1 d2 + v fb * - v fb ka431 c b v o fod817a r sense sensefet fsq0365rn rev. 00 figure 21. pulse-width-modulation (pwm) circuit 3. synchronization : the fsq-series employs a valley switching technique to minimize the switching noise and loss. the basic waveforms of the valley switching converter are shown in figure 22. to minimize the mosfet's switching loss, the mosfet should be turned on when the drain vo ltage reaches its minimum value, as shown in figure 22. the minimum drain voltage is indirectly detec ted by monitoring the v cc winding voltage, as shown in figure 22. v dc v ro v ro v ds t f 0.7v v sync 300ns delay 0.2v on on v ovp (6v) fsq0365rn rev.00 mosfet gate figure 22. valley resonant switching waveforms 4. protection circuits : the fsq-series has several self-protective functions, su ch as overload protection (olp), abnormal over-current protection (aocp), over-voltage protection (o vp), and thermal shutdown (tsd). all the protections are implemented as auto- restart mode. once the f ault condition is detected, switching is terminated and the sensefet remains off. this causes v cc to fall. when v cc falls down to the under-voltage lockout (uvlo) stop voltage of 8v, the protection is reset and the st artup circuit charges the v cc capacitor. when the v cc reaches the start voltage of 12v, the fsq-series resumes normal operation. if the fault condition is not remov ed, the sensefet remains off and v cc drops to stop voltage again. in this manner,
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 13 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter the auto-restart can alter nately enable and disable the switching of the power sensefet until the fault condition is eliminated. because these protection circuits are fully integrated in to the ic without external components, the reliabilit y is improved without increasing cost. fault situation 8v 12v v cc v ds t fault occurs fault removed normal operation normal operation power on fsq0365rn rev. 00 figure 23. auto-restart protection waveforms 4.1 overload protection (olp) : overload is defined as the load current exceeding its normal level due to an unexpected abnormal event. in this situation, the protection circuit should tri gger to protect the smps. however, even when the smps is in the normal operation, the overload pr otection circuit can be triggered during load transiti on. to avoid this undesired operation, the over load protection circuit is designed to trigger only after a specified time to determine whether it is a transient situation or a true overload situation. because of the pulse-by-pulse current limit capability, the maximum peak current through the sensefet is limited, and theref ore the maximum input power is restricted with a given i nput voltage. if the output consumes more than this maximum power, the output voltage (v o ) decreases below the set voltage. this reduces the current thr ough the opto-coupler led, which also reduces the opto- coupler transistor current, thus increasing the feedback voltage (v fb ). if v fb exceeds 2.8v, d1 is block ed and the 5a current source starts to charge cb slowly up to v cc . in this condition, v fb continues increasing until it reaches 6v, when the switching operation is termi nated, as shown in figure 24. the delay for shutdown is the time required to charge cb from 2.8v to 6v with 5a. a 20 ~ 50ms delay is typical for most applications. v fb t 2.8v 6.0v overload protection t 12 = c fb *(6.0-2.8)/i delay t 1 t 2 fsq0365rn rev.00 figure 24. overload protection 4.2 abnormal over-current protection (aocp) : when the secondary rectifier diodes or the transformer pins are shorted, a steep current with extremely high-di/dt can flow through the sensefet during the leb time. even though the fsq-series has overload protection (olp), it is not enough to protect the fsq-series in that abnormal case, since severe current stress is imposed on the sensefet until olp triggers. the fsq-series has an internal abnormal over-current protection (aocp) circuit as shown in figure 25. 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. 1 s q q r osc r 3r gnd gate driver leb 200ns pwm + - v ocp aocp r sense fsq0365rn rev.00 figure 25. abnormal over-current protection
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 14 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter 4.3 over-voltage protection (ovp) : if the secondary- side feedback circuit malfunctions or a solder defect causes an opening in the feedback path, the current through the opto-coupler transistor becomes almost zero. then v fb 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 triggers. because more energy than required is provided to the output, the output voltage may exceed the rated voltage before the overload protection triggers, resulting in the breakdown of the devices in the secondary side. to prevent this situation, an ovp circuit is employed. in general, the peak voltage of the sync signal is proportional to the output voltage and the fsq-series uses a sync signal instead of directly monitoring the output voltage. if the sync signal exceeds 6v, an ovp is triggered, shutting down the smps. to avoid undesired triggering of ovp during normal operation, the peak voltage of the sync signal should be designed below 6v. 4.4 thermal shutdown (tsd) : the sensefet and the control ic are built in one package. this makes it easy for the control ic to detect the abnormal over temperature of the sensefet. if the temperature exceeds ~150c, the thermal shutdown triggers. 5. soft-start : an internal soft-start circuit increases pwm comparator inverting input voltage with the sensefet current slowly after it starts up. the typical soft-start time is 15ms. the pulsewidth 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. this helps prevent transformer saturation and reduces stress on the secondary diode during startup. 6. burst operation : to minimize power dissipation in standby mode, the fps enters burst-mode operation. as the load decreases, the feedback voltage decreases. as shown in figure 26, the device automatically enters burst mode when the feedback voltage drops below v burl (350mv). at this point, switching stops and the output voltages start to drop at a rate dependent on standby current load. this causes the feedback voltage to rise. once it passes v burh (550mv), switching resumes. the feedback voltage then falls and the process repeats. burst mode alternately enables and disables switching of the power sensefet, reducing switching loss in standby mode. v fb v ds 0.35v 0.55v i ds v o v o set time switching disabled t1 t2 t3 switching disabled t4 fsq0365rn rev.00 figure 26. waveforms of burst operation 7. switching frequency limit : to minimize switching loss and electromagnetic interference (emi), the mosfet turns on when the drain voltage reaches its minimum value in valley switching operation. however, this causes switching frequency to increases at light load conditions. as the load decreases, the peak drain current diminishes and the switching frequency increases. this results in severe switching losses at light-load condition, as well as intermittent switching and audible noise. because of these problems, the valley switching converter topology has limitations in a wide range of applications. to overcome this problem, fsq-series employs a frequency-limit function, as shown in figure 27 and figure 28. once the sensefet is turned on, the next turn-on is prohibited during the blanking time (t b ). after the blanking time, the controller finds the valley within the detection time window (t w ) and turns on the mosfet, as shown in figure 27 and figure 28 (cases a, b, and c). if no valley is found during t w , the internal sensefet is forced to turn on at the end of t w (case d). therefore, fsq devices have a minimum switching frequency of 55khz and a maximum switching frequency of 67khz, as shown in figure 28.
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 15 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter t s max =18 ? s t s max =18 ? s t b =15 ? s t s t b =15 ? s t s t s i ds i ds i ds i ds a b c d t w =3 ? s t b =15 ? s t b =15 ? s i ds i ds i ds i ds fsq0365rn rev. 00 figure 27. valley switching with limited frequency 55khz 67khz 59khz burst mode constant frequency d c b a p o when the resonant period is 2 ? s fsq0365rn rev. 00 figure 28. switching frequency range
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 16 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter typical application circuit of fsq0365rn application fps device input voltage range rated output power output voltage (maximum current) dvd player power supply fsq0365rn 85-265v ac 19w 5.1v (1.0a) 3.4v (1.0a) 12v (0.4a) 16v (0.3a) features ? high efficiency ( >77% at universal input) ? low standby mode power consumption (<1w at 230v ac input and 0.5w load) ? reduce emi noise through valley switching operation ? enhanced system reliability through various protection functions ? internal soft-start: 15ms key design notes ? the delay time for overload protection is designed to be about 30ms with c107 of 47nf. if faster/slower triggering of olp is required, c107 can be changed to a smaller/larger value (eg. 100nf for 60ms). ? the input voltage of v sync must be higher than -0.3v. by proper voltage sharing by r106 & r107 resistors, the input voltage can be adjusted. ? the smd-type 100nf capacitor must be placed as close as possible to v cc pin to avoid malfunction by abrupt pulsating noises and to improved surge immunity . schematic 3 4 c102 100nf,275v ac lf101 40mh c101 100nf 275v ac f101 fuse c103 33 ? f 400v r102 56k ? c104 10nf 630v d101 1n 4007 ic101 fsq0365rn c105 47nf 50v c107 22 ? f 50v d102 1n 4004 r103 5 ? 1 2 3 4 5 8 9 6 12 10 11 t101 eer2828 d201 uf4003 c201 470 ? f 35v c202 470 ? f 35v l201 l203 l204 d202 uf4003 c203 470 ? f 35v c204 470 ? f 35v c206 1000 ? f 10v c205 1000 ? f 10v d203 sb360 d204 sb360 c207 1000 ? f 10v c208 1000 ? f 10v r201 510 ? r202 1k ? r203 6.2k ? r204 20k ? c209 100nf r205 6k ? ic202 fod817a bd101 bridge diode l202 v str sync fb v cc drain gnd 6 1 2 3 4 5 1 2 drain drain 7 8 ic201 ka431 16v, 0.3a 12v, 0.4a 5.1v, 1a 3.4v, 1a r104 12k ? tnr 10d471k r105 100k ? r106 6.2k ? c302 3.3nf ac in c106 100nf smd d103 1n4148 c110 33pf 50v zd101 1n4746a r107 6.2k ? rt101 5d-9 r108 62 ? c209 47pf c210 47pf fsq0365rn rev:00 figure 29. demo circuit of fsq0365rn
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 17 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter transformer eer2828 n 12v 1 6 7 8 9 10 11 12 n 16v n 5.1v n 3.4v n p /2 n a 2 3 4 5 n p /2 n 16v n 12v n a n 5.1v n 3.4v n p /2 n p /2 6mm 3mm fsq0365rn rev: 00 figure 30. transformer schematic diagram of fsq0365rn table 1. winding specification no. pin (s ? f) wire turns winding method n p /2 3 ? ? 2 0.25 ? x 1 50 center solenoid winding insulation: polyester tape t = 0.050mm, 2-layer n 3.4v 9 ? ? 8 0.33 ? x 2 4 center solenoid winding insulation: polyester tape t = 0.050mm, 2-layer n 5v 6 ? ? 9 0.33 ? x 1 2 center solenoid winding insulation: polyester tape t = 0.050mm, 2-layer n a 4 ? ? 5 0.25 ? x 1 16 center solenoid winding insulation: polyester tape t = 0.050mm, 2-layer n 12v 10 ? ? 12 0.33 ? x 3 14 center solenoid winding insulation: polyester tape t = 0.050mm, 3-layer n 16v 11 ? ? 12 0.33 ? x 3 18 center solenoid winding insulation: polyester tape t = 0.050mm, 2-layer n p /2 2 ? ? 1 0.25 ? x 1 50 center solenoid winding insulation: polyester tape t = 0.050mm, 2-layer table 2. electrical characteristics pin specification remarks inductance 1 - 3 1.4mh 10% 100khz, 1v leakage 1 - 3 25h maximum short all other pins core & bobbin ? core: eer2828 (ae=86.66mm 2 ) ? bobbin: eer2828
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 18 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter table 3. demo board part list part value note part value note resistor inductor r102 56k 1w l201 10h r103 5 1/2w l202 10h r104 12k 1/4w l203 4.9h r105 100k 1/4w l204 4.9h r106 6.2k 1/4w diode r107 6.2k 1/4w d101 in4007 r108 62 1w d102 in4004 r201 510 1/4w zd101 1n4746a r202 1k 1/4w d103 1n4148 r203 6.2k 1/4w d201 uf4003 r204 20k 1/4w d202 uf4003 r205 6k 1/4w d203 sb360 capacitor d204 sb360 c101 100nf/275v ac box capacitor c102 100nf/275v ac box capacitor ic c103 33f/400v electrolytic capacitor ic101 fsq0365rn fps? c104 10nf/630v film capacitor ic201 ka431 (tl431) voltage reference c105 47nf/50v mono capacitor ic202 fod817a opto-coupler c106 100nf/50v smd (1206) fuse c107 22f/50v electrolytic capacitor fuse 2a/250v c110 33pf/50v ceramic capacitor ntc c201 470f/35v electrolytic capacitor rt101 5d-9 c202 470f/35v electrolytic capacitor bridge diode c203 470f/35v electrolytic capac itor bd101 2kbp06m2n257 bridge diode c204 470f/35v electrolytic capacitor line filter c205 1000f/10v electrolytic capacitor lf101 40mh c206 1000f/10v electrolytic capacitor transformer c207 1000f/10v electrolytic capacitor t101 c208 1000f/10v electrolytic capacitor varistor c209 100nf /50v ceramic capacitor tnr 10d471k
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 19 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter package dimensions c 7 typ 7 typ .430 max [10.92] b a .400 .373 [ 10.15 9.46 ] .250.005 [6.350.13] .036 [0.9 typ] .070 .045 [ 1.78 1.14 ] .100 [2.54] .300 [7.62] .060 max [1.52] .310.010 [7.870.25] .130.005 [3.30.13] .210 max [5.33] .140 .125 [ 3.55 3.17 ] .015 min [0.38] .021 .015 [ 0.53 0.37 ] .010 +.005 -.000 [ 0.254 +0.127 -0.000 ] pin #1 pin #1 (.032) [r0.813] (.092) [?2.337] top view option 1 top view option 2 .001[.025] c n08erevg c. does not include mold flash or protrusions. dambar protrusions shall not exceed d. does not include dambar protrusions. b. controling dimensions are in inches a. conforms to jedec registration ms-001, mold flash or protrusions shall not exceed variations ba e. dimensioning and tolerancing notes: reference dimensions are in millimeters .010 inches or 0.25mm. .010 inches or 0.25mm. per asme y14.5m-1994. figure 31. 8-lead, dual inline package (dip) package drawings are provided as a servic e to customers considering fairchild co mponents. drawings may change in any manner without notice. please note the revision and/or date on the drawi ng and contact a fairchild semiconductor representative to ver ify 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 pack aging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/ .
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 20 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter package dimensions (continued) mkt-mlsop08areva figure 32. 8-lead, mlsop package drawings are provided as a servic e to customers considering fairchild co mponents. drawings may change in any manner without notice. please note the revision and/or date on the drawi ng and contact a fairchild semiconductor representative to ver ify 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 pack aging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/ .
? 2007 fairchild semiconductor corporation www.fairchildsemi.com fsq0365, FSQ0265, fsq0165, fsq321 ? rev. 1.0.6 21 fsq0365/0265/0165/321 ? green mode fairchild powe r switch (fps?) for valley switching converter

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