r5469 - trunk/gta02-core/docs/ecn

[werner at docs.openmoko.org]

Author: werner
Date: 2009-08-16 21:13:50 +0200 (Sun, 16 Aug 2009)
New Revision: 5469

Added:
   trunk/gta02-core/docs/ecn/ecn0029.txt
Modified:
   trunk/gta02-core/docs/ecn/STATUS
Log:
Started ECN0029, move 0R resistors on PMU outputs.



Modified: trunk/gta02-core/docs/ecn/STATUS
===================================================================
--- trunk/gta02-core/docs/ecn/STATUS	2009-08-16 19:06:57 UTC (rev 5468)
+++ trunk/gta02-core/docs/ecn/STATUS	2009-08-16 19:13:50 UTC (rev 5469)
@@ -28,3 +28,4 @@
 0026	Discuss	Improve bus termination at sd-card
 0027	Edit	Renamed some nets for clarity
 0028	Cancel	Remove USB "charge path" power switch U4905
+0029	Edit	Move 0R resistors next to PMU after caps

Added: trunk/gta02-core/docs/ecn/ecn0029.txt
===================================================================
--- trunk/gta02-core/docs/ecn/ecn0029.txt	                        (rev 0)
+++ trunk/gta02-core/docs/ecn/ecn0029.txt	2009-08-16 19:13:50 UTC (rev 5469)
@@ -0,0 +1,14 @@
+Move 0R resistors next to PMU after caps
+
+
+Each power supply leaving the PMU connects through a 0R resistor
+and then to a group of buffer (> 1 uF) and filter capacitors
+(typically < 1 uF).
+
+Joerg suggested that at least the filter capacitors - and possibly
+also the buffer capacitors - should be moved to the PMU side of
+the 0R resistor, since they're supposed to filter noise originating
+from the PMU.
+
+
+Author: Werner Almesberger <werner at openmoko.org>