some new entries to change log

git-svn-id: https://svn.code.sf.net/p/freetel/code@1798 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/smartmic/SM1000-REV-B2/Change-Log-B2.txt b/smartmic/SM1000-REV-B2/Change-Log-B2.txt
index 72a5fd1b05a2fdc89fa9610fcaabaa22405a8fa9..c56f35a0b841023422096c126c882748f60ca53b 100644 (file)
--- a/smartmic/SM1000-REV-B2/Change-Log-B2.txt
+++ b/smartmic/SM1000-REV-B2/Change-Log-B2.txt
@@ -101,3 +101,27 @@ Changes 07/22/2014 Reformatted file to fit on Schematic.
                 \r
 20. [X] Added item numbers to this file to facilitate communication. RGB 07/15/2014\r
 \r
+Latest change notes David 14 August\r
+\r
+[ ] R46 to 100k\r
+   [ ] add series R to prevent DAC distortion?\r
+   [ ] get to bottom on LM386 distortion?\r
+[ ] Add 22k betwwen DAC2 and ground\r
+    + making R46 100k lead to some analog coupling between ADC2 and DAC2,\r
+      not qute sure why, this lowers Z of this net\r
+[ ] R52 1k trimmer wasn't on my digikey order\r
+    + probably my mistake, but check BOM\r
+[ ] C36 is along way away from U6\r
+    + poss to move closer?\r
+[ ] Mic DC bias v low, about 0.3V\r
+    + should we change R39?\r
+[ ] Idea - clear labels next to each trimmers in large font\r
+    + and connectors and TP, hard to see with naked eye\r
+[ ] foot print for a small reset button\r
+    + I press it a lot, gd for experimenting\r
+[ ] 220pF to filter noise across 500k R42 but very close to op-amp\r
+[ ] highly senstive net between R53 and R42 should be shorter if possible, \r
+    as we are getting a lot of noise pick up.\r
+[ ] Move ADC power supply bypass network v close to pins 21/22 U1B and\r
+    away from switcher + as per Discovery board\r
+[ ] route op-amp bypass caps directly to op amp power supply pins on same layer.\r