[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-562796-105":59,"doc-detail-562796-en":124},{"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":117,"head_meta":119,"extra_data":121,"updated_unix":123},105,"en","switch-mode-power-supply-chip-identification","Switch Mode Power Supply Chip Identification","","Troubleshooting notes describe repairing a battery charger with two power supplies, where the primary controller is identified as TH20594 and a second unknown 6-pin SMD chip marked “67A” appears to manage bootstrap/standby power. The author shares observed architecture details, where auxiliary power from a smaller transformer winding supports the TH20594 control. Community answers suggest TH20594MC1.4 as a PWM controller reference and propose that “67A” may correspond to an ON Semi part or alternatively an op-amp/comparator or other analog device, recommending circuit tracing and pin measurements to verify.",{"@graph":69,"@context":116},[70,84,99],{"@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/switch-mode-power-supply-chip-identification/562796/",{"url":83,"name":65,"@type":85,"author":86,"headline":65,"publisher":89,"fileFormat":92,"inLanguage":63,"description":67,"dateModified":93,"datePublished":93,"encodingFormat":92,"isAccessibleForFree":94,"interactionStatistic":95},"DigitalDocument",{"name":87,"@type":88},"anakgang17","Person",{"url":74,"name":90,"@type":91},"DocShare","Organization","application/pdf","2026-10-12",true,{"@type":96,"interactionType":97,"userInteractionCount":4},"InteractionCounter",{"@type":98},"ViewAction",{"@type":100,"mainEntity":101},"FAQPage",[102,108,112],{"name":103,"@type":104,"acceptedAnswer":105},"What is TH20594 likely used for in the charger?","Question",{"text":106,"@type":107},"Community references indicate TH20594MC1.4 is a PWM controller, matching its placement as the primary PSU control chip.","Answer",{"name":109,"@type":104,"acceptedAnswer":110},"What does the “67A” marking on the small 6-pin SMD chip likely indicate?",{"text":111,"@type":107},"Answers suggest “67A” could be a date-code-like marking for an ON Semi TVS diode, but other responses argue it may be an op-amp/comparator or similar analog component depending on surrounding circuitry.",{"name":113,"@type":104,"acceptedAnswer":114},"How can the unknown chip be identified more reliably?",{"text":115,"@type":107},"Trace the circuit around the chip and measure pin behavior; perform resistance checks between pins and compare the layout/components to a typical PWM control IC pattern.","https://schema.org",{"og:url":83,"og:type":118,"og:title":65,"og:site_name":90,"og:description":67},"article",{"robots":120,"canonical":83},"index,follow",{"doc_id":122,"site_id":62},562796,1791809744,{"code":4,"msg":5,"data":125},{"doc_id":122,"user_id":126,"nickname":87,"user_avatar":127,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":128,"file_id":129,"file_url":130,"file_type":131,"file_size":132,"view_count":4,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":14,"language":133,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":134,"faqs":135,"seo_title":136,"seo_description":67,"update_tm":123,"read_time":24},962090883568,"https://ap-avatar.wpscdn.com/davatar_a8503ba1806abce46bf441b54a3ca4cd","Asked by Pentium100 on 2014-01-09T17:06:04-05:00  \nI am repairing a battery charger that uses two power supplies. TH20594 (couldn't find any info on that either) controls the primary PSU, while the mysterious chip controls the bootstrap/standby supply (aux winding on the smaller transformer provides power to the TH20594) . It does not work, but I cannot find any information about the chip.  \nThe chip is a really small 6 pin SMD package (TSSOP-6?) and is marked as \"67A\".  \n[http://radiokot.ru/forum/viewtopic.php?p=1051644&sid=36a2b98c51d1cf9c8ae6f3b1a051afb5\\#p105](http://radiokot.ru/forum/viewtopic.php?p=1051644&sid=36a2b98c51d1cf9c8ae6f3b1a051afb5#p105)[ ](http://radiokot.ru/forum/viewtopic.php?p=1051644&sid=36a2b98c51d1cf9c8ae6f3b1a051afb5#p105)[1644 is part of the schematic of a power supply](1644 is part of the schematic of a power supply) ([cannot guarantee the accuracy though](cannot guarantee the accuracy though)) .  \nAnyone knows what chip it is and where to find a datasheet for it (as well as the TH20594)? 67A:  \nTH20594:  \nEDIT: It is definitely \"67A\".  \nArchives  \nScience Questions and Answers  \nElectrical Engineering Questions and Answers Jan 9th, 2014 Archives  \nWeek 02, 2014 Archives  \nJanuary, 2014 Archives  \nTags  \nSwitch Mode Power Supply Identification  \nSurface Mount  \nBest Answer  \nAnswered by Jason Morgan on 2014-01-21T16:02:11-05:00  \nFor the TH20594: I can find references (in russian), [http://therepair.ru/topic/2887-zariadnoe-metabo-asc-30/ that states](http://therepair.ru/topic/2887-zariadnoe-metabo-asc-30/ that states) the TH20594MC1 .4 is a PWM controller, which makes sense in this context.  \nI can't read russian (I used google translate) but it seems to indicate that there are similar replacement parts with different numbers, perhaps clones by different manufacturers, e.g. TI UC3845 . Tracing out some of the components and comparing with a typical PWM control IC might give evidence to this possibility.  \nYou can find sources for the TH20594MC1 .4 in lots of places in China, but I could not find any datasheet (and it would be probably in Chinese anyway, perhaps why a doc search fails)  \nFor the '67A': The closest I can find that matches is a 67(space)A, where A is the date code. This is an ON semi quad TVS diode, NUP4302MR6 . Which given the product I doubt is correct, but perhaps I bit of probing with a DVM might yield more info to verify (negatively or positively) this.  \nI would better guess that given product and the sorts of components around it, it's an opamp or comparator.  \nSorry for the incomplete answer, it's not possible to put a so much text in a comment. Can give more info, e.g. Trace out the circuit and measure resistance between pins (in both directions) .  \nAll Answers  \nAnswered by Manu3l0us on 2014-01-10T02:00:03-05:00  \nThe G7A is probably a SOT23-6 (or SC70-6) package. Could be a dual FET, opamp/comparator, current sense amp, logic gate or an ADC/DAC. Haven't found it in the [http://de.scribd.com/doc/77462737/Turuta-Codes-Active-SMD-Semiconductor-Components-Marking](http://de.scribd.com/doc/77462737/Turuta-Codes-Active-SMD-Semiconductor-Components-Marking)[-Codes-2010](-Codes-2010) , although this seems like a good resource for such tasks.  \nAccording to some eBay sellers the TH20594MC1 .4 is a Melexis chip. But it's not listed in their page.  \nView Online  \n[http://www.rqna.net/qna/qzkkzh-help-identifying-pwm-controller-ldquo-67a-rdquo.html](http://www.rqna.net/qna/qzkkzh-help-identifying-pwm-controller-ldquo-67a-rdquo.html)","cbCaitOYVcbMdjNV","https://ap.wps.com/l/cbCaitOYVcbMdjNV","pdf",10951,"English","# Switch mode power supply troubleshooting\n## TH20594 role and references\n## Unidentified “67A” SMD chip\n## Proposed identification methods","[{\"question\":\"What is TH20594 likely used for in the charger?\",\"answer\":\"Community references indicate TH20594MC1.4 is a PWM controller, matching its placement as the primary PSU control chip.\"},{\"question\":\"What does the “67A” marking on the small 6-pin SMD chip likely indicate?\",\"answer\":\"Answers suggest “67A” could be a date-code-like marking for an ON Semi TVS diode, but other responses argue it may be an op-amp/comparator or similar analog component depending on surrounding circuitry.\"},{\"question\":\"How can the unknown chip be identified more reliably?\",\"answer\":\"Trace the circuit around the chip and measure pin behavior; perform resistance checks between pins and compare the layout/components to a typical PWM control IC pattern.\"}]","Switch Mode Power Supply Chip Identification | PDF"]