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Bug #1870
closedV1 hardware does not enumerate as long as JP4 is set
Start date:
12/05/2016
Due date:
% Done:
100%
Spec Reference:
Description
if JP4 is connected at powerup (usb connect) the cp2105 stays in reset.
this happens since its _RST is pulled up to VIO which stays powered off till the cp2105 comes out of reset and pulls _SUSPEND high which in turn enables the ldo for VIO.
the solution is to disconnect _SUSPEND of the cp21015 and _SUSPEND of the ldo and pull the ldo side high against Vbus or VDD_3V45 (does not seem to matter which)
Checklist
- re-work the existing units @ sysmocom
- change design for future production runs
Updated by roh over 7 years ago
rework manual:
- cut trace right next to R1
- place 0Ohm over the pad 3 of U3 and VBus on C6 (0603 or 0805)
Updated by laforge over 7 years ago
- Checklist item re-work the existing units @ sysmocom added
- Assignee set to roh
- % Done changed from 0 to 10
Updated by laforge over 7 years ago
- Checklist item change design for future production runs added
Updated by laforge over 7 years ago
- Checklist item change design for future production runs set to Done
design files updated in git commit 9b5d540b1ffb669effeb4ea523254935e5444278
Updated by roh almost 7 years ago
- Status changed from New to Resolved
- % Done changed from 10 to 100
reworked all existing v1 boards
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