[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-561025-105":59,"doc-detail-561025-en":129},{"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":122,"head_meta":124,"extra_data":126,"updated_unix":128},105,"en","ncp1207a-ncp1207b-pwm-current-mode-controller-for-free-running-quasi-resonant-operation","NCP1207A, NCP1207B PWM Current-Mode Controller for Free Running Quasi-Resonant Operation","","NCP1207A/B is a PWM current-mode controller that supports free-running borderline/critical quasi-resonant operation using a true current mode modulator and an ademagnetization detector. It achieves minimum drain voltage switching, includes a skip-cycle feature for burst mode at light load to reduce audible noise, and provides configurable burst foldback frequency via internal timing (8.0 ms for NCP1207A, 4.5 ms for NCP1207B). The DSS approach simplifies transformer design by avoiding an auxiliary VCC winding, while protection functions include latching OVP and monitored overcurrent fault behavior with rugged, reliable operation. ",{"@graph":69,"@context":121},[70,84,104],{"@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":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/ncp1207a-ncp1207b-pwm-current-mode-controller-for-free-running-quasi-resonant-operation/561025/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":98,"encodingFormat":97,"isAccessibleForFree":99,"interactionStatistic":100},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/ncp1207a-ncp1207b-pwm-current-mode-controller-for-free-running-quasi-resonant-operation/561025.png","ImageObject",300,407,{"name":92,"@type":93},"Adam","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-12",true,{"@type":101,"interactionType":102,"userInteractionCount":8},"InteractionCounter",{"@type":103},"ViewAction",{"@type":105,"mainEntity":106},"FAQPage",[107,113,117],{"name":108,"@type":109,"acceptedAnswer":110},"How does NCP1207A/B achieve free-running quasi-resonant operation?","Question",{"text":111,"@type":112},"It uses a true current mode modulator together with an ademagnetization detector to maintain full borderline/critical conduction mode and enable minimum drain voltage switching in quasi-resonant operation.","Answer",{"name":114,"@type":109,"acceptedAnswer":115},"What determines when the controller enters burst mode?",{"text":116,"@type":112},"With its inherent skip cycle capability, the controller enters burst mode as soon as power demand falls below a predetermined level, and this occurs at low peak current to prevent audible noise.",{"name":118,"@type":109,"acceptedAnswer":119},"How do NCP1207A and NCP1207B differ in frequency capability?",{"text":120,"@type":112},"NCP1207A uses an internal 8.0 ms timer to prevent free-run frequency from exceeding 125 kHz (below CISPR-22 EMI starting at 150 kHz), while NCP1207B reduces the timer duration to 4.5 ms to allow operation up to 200 kHz.","https://schema.org",{"og:url":83,"og:type":123,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":125,"canonical":83},"index,follow",{"doc_id":127,"site_id":62},561025,1791834157,{"code":4,"msg":5,"data":130},{"doc_id":127,"user_id":131,"nickname":92,"user_avatar":132,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":133,"file_id":134,"file_url":135,"file_type":136,"file_size":137,"view_count":8,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":138,"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":144},1374404737137,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","NCP1207A, NCP1207B PWM Current--Mode Controller for Free Running Quasi--Resonant Operation  \nThe NCP1207A/B combines a true current mode modulator and ademagnetization detector to ensure full borderline/critical Conduction Mode in any load/line conditions and minimum drain voltage switching (Quasi--Resonant operation). Due to its inherent skip cycle capability, the controller enters burst mode as soon as the power demand falls below a predetermined level. As this happens at low peak current, no audible noise can be heard. For the NCP1207A, an internal 8.0 ms timer prevents the free--run frequency to exceed 125 kHz (therefore below the 150 kHz CISPR--22 EMI starting limit), while the skip adjustment capability lets the user select the frequency at which the burst foldback takes place. For the NCP1207B, the internal timer duration is reduced to 4.5 ms to allow operation at higher frequencies (up to 200 kHz) .  \nThe Dynamic Self--Supply (DSS) drastically simplifies the transformer design in avoiding the use of an auxiliary winding to supply the NCP1207A/B. This feature is particularly useful in applications where the output voltage varies during operation (e.g. battery chargers) . Due to its high--voltage technology, the IC is directly connected to the high--voltage DC rail. As a result, the short--circuit trip point is not dependent upon any VCC auxiliary level.  \nThe transformer core reset detection is done through an auxiliary winding which, brought via a dedicated pin, also enables fast Overvoltage Protection (OVP) . Once an OVP has been detected, the IC permanently latches off.  \nFinally, the continuous feedback signal monitoring implemented with an overcurrent fault protection circuitry (OCP) makes the final design rugged and reliable.  \n􀁸 Free--Running Borderline/Critical Mode Quasi--Resonant Operation  \n􀁸 Current--Mode with Adjustable Skip--Cycle Capability  \n􀁸 No Auxiliary Winding VCC Operation  \n􀁸 Auto--Recovery Overcurrent Protection  \n􀁸 Latching Overvoltage Protection  \n􀁸 External Latch Triggering, e.g. Via Overtemperature Signal  \n􀁸 500 mA Peak Current Source/Sink Capability  \n􀁸 Undervoltage Lockout for VCC Below 10 V  \n􀁸 Internal 1 .0 ms Soft--Start  \n􀁸 Internal 8.0 ms Minimum T OFF for NCP1207A,  \n4.5 ms Minimum T OFF for NCP1207B  \n􀁸 Adjustable Skip Level  \n􀁸 Internal Temperature Shutdown  \n􀁸 Direct Optocoupler Connection  \n􀁸 SPICE Models Available for TRANsient Analysis  \n􀁸 These are Pb--Free and Halide--Free Devices  \nTypical Applications  \n􀁸 AC/DC Adapters for Notebooks, etc.  \n􀁸 Offline Battery Chargers  \n􀁸 Consumer Electronics (DVD Players, Set--Top Boxes, TVs, etc.)  \n􀁸 Auxiliary Power Supplies (USB, Appliances, TVs, etc.)  \n[http://onsemi.com](http://onsemi.com)  \nMARKING DIAGRAM  \n1207A/B/AP = Device Code  \nA = Assembly Location  \nL, WL = Wafer Lot  \nY, YY = Year  \nW, WW = Work Week  \nG or G = Pb--Free Package  \nPIN CONNECTIONS  \nDmg  \nFB  \nCS  \nGND  \n\n| 1 | | 8 |\n| --- | --- | --- |\n|  |  |  |\n| 2 |  | 7 |\n|  |  |  |\n| 3 |  | 6 |\n|  |  |  |\n| 4 |  | 5 |\n|  |  |  |\n\nHV  \nNC  \nV CC  \nDrv  \nORDERING INFORMATION  \n\n| Device | Package | Shipping† |\n| --- | --- | --- |\n| NCP1207ADR2G | SOIC--8\u003Cbr>(Pb--Free) | 2500/Tape & Reel |\n| NCP1207APG | PDIP--8\u003Cbr>(Pb--Free) | 50 Units / Rail |\n| NCP1207BDR2G | SOIC--7\u003Cbr>(Pb--Free) | 2500/Tape & Reel |\n\n†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D.  \nNCP1207A, NCP1207B  \nFigure 1. Typical Application  \nPIN FUNCTION DESCRIPTION  \n\n| Pin | Pin Name | Function | Description |\n| --- | --- | --- | --- |\n| 1 | Demag | Core reset detection and OVP | The auxiliary FLYBACK signal ensures discontinuous operation and offers a fixed overvoltage detection level of 7.2 V. |\n| 2 | FB | Sets the peak current setpoint | By connecting an Optocoupler to this pin, the peak current setpoint is adjusted accordingly to the output power demand. By bringing this pin belo","cbCaimaeN7Sc6VnK","https://ap.wps.com/l/cbCaimaeN7Sc6VnK","pdf",405106,17,"English","# Free-Running Borderline/Critical Mode Quasi-Resonant Operation\n## Current-Mode with Adjustable Skip-Cycle Capability\n## No Auxiliary Winding VCC Operation\n## Overcurrent and Overvoltage Protection Features\n## Typical Applications","[{\"question\":\"How does NCP1207A/B achieve free-running quasi-resonant operation?\",\"answer\":\"It uses a true current mode modulator together with an ademagnetization detector to maintain full borderline/critical conduction mode and enable minimum drain voltage switching in quasi-resonant operation.\"},{\"question\":\"What determines when the controller enters burst mode?\",\"answer\":\"With its inherent skip cycle capability, the controller enters burst mode as soon as power demand falls below a predetermined level, and this occurs at low peak current to prevent audible noise.\"},{\"question\":\"How do NCP1207A and NCP1207B differ in frequency capability?\",\"answer\":\"NCP1207A uses an internal 8.0 ms timer to prevent free-run frequency from exceeding 125 kHz (below CISPR-22 EMI starting at 150 kHz), while NCP1207B reduces the timer duration to 4.5 ms to allow operation up to 200 kHz.\"}]","NCP1207A, NCP1207B PWM Current-Mode Controller for Free Running Quasi-Resonant Operation | PDF",1791804786,43]