{"id":798,"date":"2012-08-23T17:42:58","date_gmt":"2012-08-23T15:42:58","guid":{"rendered":"http:\/\/www.sciencetronics.com\/greenphotons\/?p=798"},"modified":"2025-06-16T18:38:19","modified_gmt":"2025-06-16T16:38:19","slug":"counterfeit-electronics","status":"publish","type":"post","link":"https:\/\/www.sciencetronics.com\/greenphotons\/?p=798","title":{"rendered":"Counterfeit electronics?!"},"content":{"rendered":"

My latest post was about differences within legitimate versions of the same integrated circuit from different manufacturers,<\/a> today I’d like to write about experiences with supposedly counterfeit components.<\/p>\n

It has been in the media that the electronic component market is fighting with counterfeit products from the far east. I myself encountered possible indications of such fake copies of high-quality capacitors in a consulting job for a big Swedish company last year, but nothing was proven then, it was just a suspicion combined with poor circuit design from the side of the company.<\/p>\n

Earlier this year I have purchased quite a few electronic components from Chinese sellers on eBay.<\/a> Unlike many European distributors (Elfa, Conrad, Pollin, Reichelt, Digikey, Farnell, RS, Electrokit) these sellers offer a wide range of recent electronic components at small quantities, hazzle-free and without unreasonably high shipment costs. I don’t know where the components in question come from, and I choose to not care for my private projects.<\/p>\n

In general I have made very good experiences, the delivery time to Sweden is generally in the order of 2 weeks – and if you are not in a hurry, this is ok.<\/p>\n

Continuing to play around with microcontrollers, and at the same time preparing lectures and projects for a course at Uppsala University<\/a> I ordered a couple of real-time clock chips DS1307<\/a>. Controlled via the serial I2C interface, these chips are supposedly easy to connect to an Atmel AVR microcontroller.<\/a><\/p>\n

However, it didn’t work for me at all. After a couple of successful read and write accesses the I2C bus became blocked, some of the DS1307 chips which I tested became even hot, and all of them refused to work at all in subsequent tries.<\/p>\n

I started to doubt myself, read the datasheet of the AVR controller, the datasheet of the DS1307 chip, googled the internet, looked up the I2C specifications, even programmed my very own bit-banging I2C routines – no success.<\/p>\n

Sources on the internet pointed out the importance of the correct impedance of the 32.768 kHz quartz attached to the real-time chip – mine of course also came via eBay, unspecified directly from some garage sale in China, but I doubted that it should affect the function of the I2C bus.<\/p>\n

Later in spring I approached representatives from Maxim<\/a> on the Scandinavian Electronics Fair<\/a> in Stockholm. They were kind enough to send me some samples of genuine DS1307 chips for testing and teaching.<\/p>\n

As you can see from the picture, the genuine DS1307 chips look different from the ones I got from China! I even ordered them (at roughly no cost at all) from different eBay sellers, but all of those looked the same.<\/p>\n

\"\"<\/a>
Genuine part or counterfeit? Two supposedly identical chips, one a sample from the manufacturer, the other one bought online from Chinese sellers on eBay. One is working, the other one is crap…<\/figcaption><\/figure>\n

And yes, the sample chips I got directly from Maxim seem to run without major problems – once in a while the I2C bus seems to get stuck even here, but the clock continues to run internally in the DS1307, nothing gets hot, even the pulse-output on the DS1307 stays active. On the other hand I have never managed to get the pulse output on the Chinese chips to work at all…<\/p>\n

Lesson learned? Well I still buy electronics from Chinese sellers on eBay, but I do not trust any of them anymore…<\/p>\n","protected":false},"excerpt":{"rendered":"

My latest post was about differences within legitimate versions of the same integrated circuit from different manufacturers, today I’d like to write about experiences with supposedly counterfeit components. It has been in the media that the electronic component market is fighting with counterfeit products from the far east. I myself encountered possible indications of such […]<\/p>\n","protected":false},"author":1,"featured_media":799,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"enabled":false},"version":2}},"categories":[11,8],"tags":[],"class_list":["post-798","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-electronics_en","category-everything_en","entry","has-media"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.sciencetronics.com\/greenphotons\/wp-content\/uploads\/2012\/08\/IMGP0001a_500.jpg","jetpack_shortlink":"https:\/\/wp.me\/p48grL-cS","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/posts\/798","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=798"}],"version-history":[{"count":3,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/posts\/798\/revisions"}],"predecessor-version":[{"id":2495,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/posts\/798\/revisions\/2495"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=\/wp\/v2\/media\/799"}],"wp:attachment":[{"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sciencetronics.com\/greenphotons\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}