minor layout adjustments, feedforward cap value

Change feedforward cap to 330 pF so the transfer function of the feedback network will be similar to that of the datasheet example. Our feedback resistors are lower and the impedance of the cap needs to be proportionally lower. Correct typo in notes on power schematic page. Change buck feedforward cap footprint from Kicad lib to launch lib for consistency. Arrange schematic components so "330 pF" does not overlap adjacent components. Move "U4" silkscreen to not overlap inductor pad. Add a 2nd via to each buck converter ground, move feedback components to allow. Reroute some signal traces to reduce number of vias, have more solid ground planes around the buck converters. This included CL_SEL, RESET, VCC (to enable).
system76 · May 27, 2021 · e4924c9 · e4924c9
1 parent 0ef65db
commit e4924c9
Show file tree

Hide file tree

Showing 5 changed files with 2,721 additions and 2,657 deletions.
diff --git a/pcb/USB.sch b/pcb/USB.sch
@@ -5,7 +5,7 @@ $Descr A3 16535 11693
 encoding utf-8
 Sheet 2 3
 Title ""
-Date "2020-07-15"
+Date "2021-05-27"
 Rev ""
 Comp ""
 Comment1 ""

diff --git a/pcb/launch-bom.csv b/pcb/launch-bom.csv
@@ -4,7 +4,7 @@ C25 C26 C27 C33 C59 C61 C64 C66 C60 C62 C65 C67 ,12,2.2 uF,Capacitor_SMD:C_0603_
 C34 C32 C49 C48 ,4,22 uF,Capacitor_SMD:C_0805_2012Metric,Generic X5R capacitor
 C44 C46 C47 C45 ,4,APXF6R3ARA151ME40G,Capacitor_SMD:CP_Elec_5x5.8,United Chemi-Con
 C6 C5 ,2,22 pF,Capacitor_SMD:C_0805_2012Metric,Generic NP0 capacitor
-C68 C69 ,2,22 pF,Capacitor_SMD:C_0402_1005Metric,Generic NP0 capacitor
+C68 C69 ,2,330 pF,launch:C_0402_1005Metric,Generic NP0 capacitor
 C7 ,1,1 nF,launch:C_0402_1005Metric,Generic X7R capacitor
 D2 D5 D4 D1 D3 D8 D7 D6 ,8,PUSB3FR4Z,launch:DFN-10_1x2.5mm_P0.5mm,Nexperia
 D9 D10 D11 D12 D13 D14 D15 D16 D18 D19 D20 D21 D22 D23 D24 D25 D26 D27 D28 D29 D30 D31 D32 D33 D34 D35 D36 D37 D38 D39 D40 D41 D42 D43 D44 D45 D46 D47 D48 D49 D50 D17 ,42,"BAV70,215",Package_TO_SOT_SMD:SOT-23,Nexperia