[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-560876-105":59,"doc-detail-560876-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","str-f6653-functional-description-power-supply-appendix-operations-and-protection","STR-F6653 Functional Description - Power Supply Appendix - Operations and Protection","","The document explains the functional description of the STR-F6653 hybrid IC used in flyback-converter switch-mode power supplies. It details how the start-up circuit detects VIN at pin 4, begins control when VIN reaches 16V, and continues operation until VIN reaches the 11V shutdown voltage logic. It also describes oscillating operation using internal capacitor charging/discharging that sets MOSFET off-time, including OCP/FB threshold behavior and MOSFET switching waveforms. Finally, it covers protection circuits: pulse-by-pulse overcurrent protection, latch behavior during OVP and TSD, thermal shutdown at 140°C, and overvoltage latch triggering when VIN exceeds about 22V.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/str-f6653-functional-description-power-supply-appendix-operations-and-protection/560876/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/str-f6653-functional-description-power-supply-appendix-operations-and-protection/560876.png","ImageObject",300,407,{"name":92,"@type":93},"Đào","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-19","2026-10-12",true,{"@type":102,"interactionType":103,"userInteractionCount":19},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"How does the start-up circuit for STR-F6653 control operation start and stop?","Question",{"text":112,"@type":113},"Operation starts when VIN detected at pin 4 reaches 16V, and continues because VIN is smoothed from the transformer winding. The control continues until VIN falls to the shutdown condition at around 11V.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"What sets the MOSFET off-time during STR-F6653 oscillating operation?",{"text":117,"@type":113},"When the MOSFET turns OFF, the internal capacitor C1 discharges through internal resistance R1. The fixed time determined by C1 and R1 corresponds to the MOSFET off-time.",{"name":119,"@type":110,"acceptedAnswer":120},"How are overcurrent, thermal shutdown, and overvoltage protections handled?",{"text":121,"@type":113},"Overcurrent protection detects, pulse by pulse, the MOSFET drain-current peak at the OCP/FB pin. The latch circuit stops power-supply operation when overvoltage protection (OVP) or thermal shutdown (TSD) is active. TSD triggers the latch when die/frame temperature exceeds 140°C, and OVP triggers it when VIN exceeds about 22V (typ.).","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},560876,1792101002,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":19,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":19,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":52},1374402968488,"https://ap-avatar.wpscdn.com/davatar_29158cc5080c5b710cf443261637dec0","APPENDIX  \n~~ FUNCTIONAL DESCRIPTION ~~  \n8. Power supply (STR F6653)  \n8-1. STR-F6653 general description  \nThe STR-F6653 is an hybrid IC with a build-in MOSFET and control IC, designed for flyback converter type switch mode power supply applications.  \n8-2. Power supply primary part operations  \nAn oscillator generates pulse signals which turn on and offa MOSFET transistor.  \n8-2-1. Start-up circuit: VIN  \nThe start-up circuit is used to start and stop the operation of the control IC, by detecting a voltage appearing atthe VIN pin (pin 4) .  \nAs soon as VIN reaches 16V, the STR-F6653 control circuit starts operating. Then, VIN is obtained by smoothing the winding voltage which appears between pin 6 and pin 7 of the SMPS transformer.  \nAs this winding voltage does not increase to the set voltage immediately after the control circuit starts operating, VIN starts dropping. However, as this winding voltage reaches the set value before VIN voltage drops to the shutdown voltage (at 11V), the control circuit continues operating (see below, VIN voltage at start-up) . Resistor R805 prevents variations of voltage atthe VIN pin, as some regulation of the SMPS transformer occurs due to secondary side output current  \nVIN must be set higher than the shutdown voltage (VIN (off) = 11Vmax) and lower than the O.V.P. (overvoltage protection) operating voltage (VOVP = 20.5V min) .  \nAPPENDIX  \n~~ FUNCTIONAL DESCRIPTION ~~  \nVin  \nO.V.P.volt age 20.5V  \n16V (TY P.)  \nShutdown voltage 11V  \nt  \nWaveform of Vin pin voltage at start-up  \n8-2-1. STR-F6653 oscillating operation  \n\n| \u003Cbr>3 TOPIN4 SMPS DRAIN\u003Cbr>2\u003Cbr>1\u003Cbr>SOURCE\u003Cbr>OCP/FB\u003Cbr>R808\u003Cbr>From PIN 6\u003Cbr>SMPS\u003Cbr>(FEEDBACK)\u003Cbr>C850 R804\u003Cbr>5 |  |\n| --- | --- |\n| | GND |\n| Oscillating operation |  |\n\nAPPENDIX  \n~~ FUNCTIONAL DESCRIPTION ~~  \n| C1\u003Cbr>(STR-F6653 internal capacitor) |  | 6.5V\u003Cbr>3.7V | |\n| --- | --- | --- | --- |\n| Pin 1 (OCP / FB) | 0.73V 0V |  |  |\n| I D (MOSFET drain current)\u003Cbr>V DS (MOSFET drain-source voltage)\u003Cbr>MOS F E sitching ON / OFF |  |  |  |\n| Waveforms during oscillating operation |  |  |  |\n\n-When the MOSFET is ON, the STR-F6653 internal capacitor C1 is charged atthe constant voltage 6.5V.  \nAtthe same time, the voltage at pin 1 (OCP / FB) increases with the same waveform as the MOSFET drain current.  \n-When the pin 1 voltage reaches the threshold voltage VTH1 = 0.73V, the STR-F6653 internal comparator 1 starts operating. The STR-F6653 internal oscillator is inverted and the MOSFET turns OFF.  \n-When the MOSFET turns OFF, charging ofSTR-F6653 internal capacitor C1 is released and C1 starts discharging by the STR-F6653 internal resistance R1. So, C1 voltage starts falling in accordance to the gradient regulated by the constant discharging time ofC1 and R1 . So, this means that the fixed time determined by C1 and R1 is the OFF-time of the MOSFET.  \n-When C1 voltage falls to around 3.7V, the STR-F6653 internal oscillator is reversed again and the MOSFET turns ON. C1 is quickly charged to around 6.5V  \nThe MOSFET continues to oscillate by repeating the above procedure.  \nAPPENDIX  \n~~ FUNCTIONAL DESCRIPTION ~~  \n8-2-3. STR-F6653 protection circuits  \novercurrent protection function (OCP)  \nOvercurrent protection is performed pulse by pulse detecting at STR-F6653 pin 1 (OCP) the peak ofthe MOSFET drain current in every pulse.  \nlatch circuit  \nThis circuit sustains an output lowfrom the STR-F6653 internal oscillator and stops operation of the power supply when overvoltage protection (OVP) and thermal shutdown (TSD) circuit are in operation  \nthermal shutdown circuit (TSD)  \nThis circuit triggers the latch circuit when the frame temperature ofSTR-F6653 IC exceeds 140°C  \novervoltage protection circuit (OVP)  \nThis circuit triggers the latch circuit when the Vin voltage exceeds 22V (typ.)  \n9. TV start-up, TV normal run and stand by mode operations  \n9-1. TV start-up operations  \n9-1-1. Schematic diagram for start-up operations","cbCairi54EYqg8YR","https://ap.wps.com/l/cbCairi54EYqg8YR","pdf",141479,"English","# FUNCTIONAL DESCRIPTION\n## Power supply (STR F6653)\n## Power supply primary part operations\n### Start-up circuit: VIN\n### STR-F6653 oscillating operation\n## STR-F6653 protection circuits\n### Overcurrent protection (OCP)\n### Latch circuit\n### Thermal shutdown (TSD)\n### Overvoltage protection (OVP)\n## TV start-up, TV normal run and stand by mode operations","[{\"question\":\"How does the start-up circuit for STR-F6653 control operation start and stop?\",\"answer\":\"Operation starts when VIN detected at pin 4 reaches 16V, and continues because VIN is smoothed from the transformer winding. The control continues until VIN falls to the shutdown condition at around 11V.\"},{\"question\":\"What sets the MOSFET off-time during STR-F6653 oscillating operation?\",\"answer\":\"When the MOSFET turns OFF, the internal capacitor C1 discharges through internal resistance R1. The fixed time determined by C1 and R1 corresponds to the MOSFET off-time.\"},{\"question\":\"How are overcurrent, thermal shutdown, and overvoltage protections handled?\",\"answer\":\"Overcurrent protection detects, pulse by pulse, the MOSFET drain-current peak at the OCP/FB pin. The latch circuit stops power-supply operation when overvoltage protection (OVP) or thermal shutdown (TSD) is active. TSD triggers the latch when die/frame temperature exceeds 140°C, and OVP triggers it when VIN exceeds about 22V (typ.).\"}]","STR-F6653 Functional Description - Power Supply Appendix - Operations and Protection | PDF",1791804370]