[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-562827-105":59,"doc-detail-562827-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","application-note-an4129-green-current-mode-pwm-controller-fan7601-operation-and-features","Application Note AN4129 - Green Current Mode PWM Controller FAN7601 - Operation and features","","Application Note AN4129 explains the operation and key features of the FAN7601 green current mode PWM controller. It focuses on burst-mode operation to reduce power loss at light/no load, an internal start-up switch to minimize losses in external start-up circuits, and system protection using a latch pin for functions such as over-voltage and thermal shutdown. It details start-up behavior, UVLO start/stop thresholds, over-voltage shutdown at 19V, soft-start timing, and required component considerations for Vcc and gate-drive currents, plus oscillator programming.",{"@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/application-note-an4129-green-current-mode-pwm-controller-fan7601-operation-and-features/562827/",{"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/application-note-an4129-green-current-mode-pwm-controller-fan7601-operation-and-features/562827.png","ImageObject",300,407,{"name":92,"@type":93},"anakgang17","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-13","2026-10-12",true,{"@type":102,"interactionType":103,"userInteractionCount":81},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What is the purpose of burst mode in the FAN7601?","Question",{"text":112,"@type":113},"Burst mode is used to reduce power loss when the system operates at light load and no load conditions.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How does the internal start-up switch affect start-up efficiency?",{"text":117,"@type":113},"The FAN7601 uses an internal start-up switch to charge the Vcc capacitor with a low current, reducing losses compared with conventional external start-up circuits.",{"name":119,"@type":110,"acceptedAnswer":120},"How is the soft-start time determined for the FAN7601?",{"text":121,"@type":113},"Soft-start time Tss is calculated as Tss = Css / 12µA, where Css is the soft-start capacitor value.","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},562827,1791826005,{"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":81,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":41},962090883568,"https://ap-avatar.wpscdn.com/davatar_a8503ba1806abce46bf441b54a3ca4cd","Application Note AN4129  \nGreen Current Mode PWM Controller FAN7601  \n1. Introduction  \nThis application note describes the operation and features of the FAN7601 . This device is a BCDMOS programmable frequency current mode PWM controller which is designed for off-line adapter applications and auxiliary power supplies. To reduce power loss at light and no load, the FAN7601 operates in burst mode and it includes a start-up switch to reduce the losses in the start-up circuit.  \nBecause of the internal start-up switch and burst mode operation, it is possible to supply an output power of 0.5W with under 1W input power when the input line voltage is 265V. On no load condition, input power is under 0.3W. The FAN7601 offers a latch protection pin for the protection of the system e.g. over voltage protection and/or thermal shutdown.  \nThe internal over voltage protection function shuts down the IC operation when the supply voltage reaches 19V. In addition, a soft start function is provided, and the soft start time can be varied. Figure 1 shows a block diagram for the  \nFAN7601 .  \nIt contains the following blocks.  \n• Start-up circuit and reference • Oscillator  \n• Soft start and latch  \n• Current sense and feed back • Burst mode  \n• Output drive  \nRt/Ct  \nLatch/SS  \nGND  \nVref Vstr  \n8 1  \nEnable 5V Ref  \n+  \n−  \n−  \n+  \n−  \nFigure 1. Internal Block Diagram of the FAN7601  \nRev. 1.0.1  \n2. Device Block Description  \n1. Start-up Circuit And Reference  \nThe FAN7601 contains a start-up switch to reduce power loss in the external start-up circuit of conventional PWM converters. The internal start-up circuit charges the Vcc capacitor with a 1mA current source if the line is connected until the soft start is completed as shown in Fig. 2. The soft start function starts when the Vcc voltage reaches the start threshold voltage(typically 12V) and it ends when the LATCH/SS pin voltage reaches 1V. The internal start-up circuit starts charging the Vcc capacitor again if the Vcc voltage is lowered to the minimum operating voltage (typically 8V) . In such a case the UVLO block shuts down the output drive circuit and some other blocks to reduce the IC current, and the soft start capacitor is discharged to zero voltage. If the Vcc voltage reaches the start threshold voltage, the IC starts switching again and the soft start capacitor is charged from zero voltage. The internal start-up circuit supplies  \ncurrent until the soft start is completed .  \nTime  \nFigure 2. Start-up Current and Vcc Voltage  \nFigure 3 shows a typical start-up sequence for the FAN7601 . The Vcc voltage should be higher than the minimum operating voltage at start-up to enter a steady state. If the Vcc voltage is higher than 19V, the over voltage protection function works. There is some delay in the over voltage protection circuit. The Vcc capacitor can be selected according to the soft start time and total gate charge(Qg) of the MOSFET. In the data sheet, the operating supply current is measured with a 1nF capacitor connected at the OUT pin. Therefore the real operating current necessary for the IC operation excluding the MOSFET drive is typically 2mA. During the soft start period (Tss), the Vcc capacitor is charged by a 1mA start-up current from the Vstr pin and the Vcc capacitor is discharged by a 2mA IC operating current and the MOSFET gate drive current. The MOSFET gate drive current is Qg×fsw. Qg increases according to the MOSFET drain source voltage, therefore the drive current is maximum when the input line voltage is highest. During the soft start period , the converter output voltage is very low, so few  \ncurrent is supplied to the Vcc capacitor from the Vcc winding. Therefore the Vcc capacitor must be large enough to supply sufficient current during the soft start time when starting up. The value of the Vcc capacitor is determined by (1) where 4V is the UVLO hysteresis and 2mA is the IC operating current and 1mA is the start-up current.  \nTss ⋅ (2mA – 1mA + Qg ⋅ fsw )  ","cbCaiemKJrC5sgCg","https://ap.wps.com/l/cbCaiemKJrC5sgCg","pdf",365872,12,"English","# Introduction\n## Device Block Description\n### Start-up Circuit And Reference\n### Oscillator\n### Soft Start and Latch","[{\"question\":\"What is the purpose of burst mode in the FAN7601?\",\"answer\":\"Burst mode is used to reduce power loss when the system operates at light load and no load conditions.\"},{\"question\":\"How does the internal start-up switch affect start-up efficiency?\",\"answer\":\"The FAN7601 uses an internal start-up switch to charge the Vcc capacitor with a low current, reducing losses compared with conventional external start-up circuits.\"},{\"question\":\"How is the soft-start time determined for the FAN7601?\",\"answer\":\"Soft-start time Tss is calculated as Tss = Css / 12µA, where Css is the soft-start capacitor value.\"}]","Application Note AN4129 - Green Current Mode PWM Controller FAN7601 - Operation and features | PDF",1791809819]