From dd8e734bc631221f5d83ef1cd1efcd436df99bbb Mon Sep 17 00:00:00 2001 From: drowe67 Date: Wed, 24 Sep 2014 21:08:59 +0000 Subject: [PATCH] added note about U3 overheating git-svn-id: https://svn.code.sf.net/p/freetel/code@1852 01035d8c-6547-0410-b346-abe4f91aad63 --- smartmic/SM1000-C/Change-Log-C.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/smartmic/SM1000-C/Change-Log-C.txt b/smartmic/SM1000-C/Change-Log-C.txt index 154dd649..f5e60bf5 100644 --- a/smartmic/SM1000-C/Change-Log-C.txt +++ b/smartmic/SM1000-C/Change-Log-C.txt @@ -301,6 +301,12 @@ Status: Researching effect on TPS54329E SW PS chip. RGB 09/15/14 62. Do we want CN9 to disable RJ45 PTT or perhaps have both in parallel? Do all radios switch PTT to ground? Or should both ends of LD2 be routed to CN9 and CN14? +63. U3 (USB chip) is hot to touch, in normal operation and USB boot mode. + + same chip isn't hot on Discovery + + suspect this is a "David error" - e.g. wrong resistors loaded, + pot is also glued to PCB nearby which may be shorting and USB + connector has become detached once so there may be a short. + Questions: 1. SM1000 designed to be operated with 6-16V power supply. Would should recommend 9-15V. Should we recommend PS? Many will operate at 13.8V(rig supply). Do we risk ground loops, etc. using rig supply? 2. Should C37, C39, C40 be 50V? Or, only caps connected to VIN? -- 2.25.1