{"id":2664,"date":"2015-08-22T02:37:34","date_gmt":"2015-08-22T02:37:34","guid":{"rendered":"http:\/\/41j.com\/blog\/?p=2664"},"modified":"2015-08-22T02:41:24","modified_gmt":"2015-08-22T02:41:24","slug":"ad5791-shield-first-rev","status":"publish","type":"post","link":"https:\/\/41j.com\/blog\/2015\/08\/ad5791-shield-first-rev\/","title":{"rendered":"AD5791 Shield First Rev"},"content":{"rendered":"<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/41j.com\/blog\/wp-content\/uploads\/2015\/08\/photo2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter  wp-image-2667\" src=\"http:\/\/41j.com\/blog\/wp-content\/uploads\/2015\/08\/photo2.jpg\" alt=\"photo(2)\" width=\"513\" height=\"383\" \/><\/a>I received the <a href=\"http:\/\/41j.com\/blog\/2015\/08\/ad5791-arduino-shield\/\">AD5791 Arduino shield<\/a> PCBs from the fab today. And built them up. There are a number of revisions that I&#8217;ll need to make:<\/p>\n<ul>\n<li>The holes on the SMA connector are too small.<\/li>\n<li>AGND and DGND are not tied near the AD5791<\/li>\n<li>The Pads on U1,U2 and U3 are too far apart for my liking.<\/li>\n<li>U3 has a via on a pad which I don&#8217;t like<\/li>\n<li>The Tantalum caps should have polarity markings.<\/li>\n<li>U5 silk marking is unclear (actually a lot of the silk is unclear)<\/li>\n<li>C23 footprint is wrong cap type<\/li>\n<li>C5 has the wrong polarity in the schematic<\/li>\n<li>pin 7 on U1 is NC. It should be connected to the feedback resistor. I blame Kicad.<\/li>\n<li>pin 5&amp;6 and 2&amp;3 on U3 are the wrong way round (can&#8217;t blame Kicad for that!).<\/li>\n<li>U1B is wrong in the schematic (inverting\/non-inverting pins incorrectly labeled) but the layout is correct.<\/li>\n<\/ul>\n<p>I patched the board and it appears to work. I&#8217;m slightly concerned out the output buffer opamp. For some reason it seems to have gain, which causes issues. A new rev is required anyway&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; I received the AD5791 Arduino shield PCBs from the fab today. And built them up. There are a number of revisions that I&#8217;ll need to make: The holes on the SMA connector are too small. AGND and DGND are not tied near the AD5791 The Pads on U1,U2 and U3 are too far apart [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[],"class_list":["post-2664","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p1RRoU-GY","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/posts\/2664","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/comments?post=2664"}],"version-history":[{"count":3,"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/posts\/2664\/revisions"}],"predecessor-version":[{"id":2669,"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/posts\/2664\/revisions\/2669"}],"wp:attachment":[{"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/media?parent=2664"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/categories?post=2664"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/41j.com\/blog\/wp-json\/wp\/v2\/tags?post=2664"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}