t3ddftw / BlueBus - History

[IMP] hardware: v1.5 High Voltage improvements
* Remove XRP6759
* Remove Old Tantalum C1
* Remove V1
* Remove L1
* Add common mode choke at input (L1) to filter out A/C
* Add new Aluminum Polymer input Capacitor rated for 35v (40v transcients) (C1)
* Add MPQ4420 wide input voltage switching regulator for 12v -> 5v regulation
* Add XC6702 to protect Q2 from trancients and provide a constant voltage to TEL ON and Microphone power
* Power Microphone through 12v rail
* Rewire 3.3v net
* Rewire 5v net
* Fix decoupling cap positioning for PIC24
* Fix decoupling cap positioning for FT232RL

[IMP] hardware: v1.2 minor update
* Re-wire microphone input for less 45 degree turns

[IMP] hardware: V 1.2
* Power PAM8406 PVDDR and add bypass caps
* Rework layout for PAM8406 and its passives
* Connect floating VIAs to ground

[IMP] hardware: V 1.1
* Reroute 3.3v rail under the PIC24 to prevent ground returns on the second layer from having to take a longer route
* Bring 5v rail to top layer for a short run in order to open the ground return path (to the left of the PIC24)
* Leave pin 3 of the SPKR_OUT connector floating to prevent audio channel grounding on certain models
* Add space between the edge of the analog audio ground plane end and the R/L channel traces
* VIA stitch layers around the ground "bridge" (right above the BlueBus name on the Silkscreen)
* Increase GND bridge to 1mm from 0.75mm
* Increase BC127 pad size to allow more paste to fill the castellations
* Bring RC filter for BC127 closer to power pin

[IMP] hardware: Add via to create ground pour
* Add VIA to area without a GND pour
* Alter AGND routing slightly

[IMP] hardware: Production V1
* Fix issue with silkscreen names
* Add ground VIA

[IMP] hardware: Production V1
* Add Fiducials
* Fix bugs with PCM5122 DGND being floating and VCOM not being tied to AGND
* Adjust routing so that all traces intersect at 90 degree angles on different layers
* Adjust traces to not follow the same track on different sides of the board
* Add additional ground stiches
* Improve placement of decoupling caps for superior ground returns

[IMP] hardware: Update Varistor wiring
* Improve Schematic drawing for circuit protection

[IMP] hardware: Revision D.1
* Remove errant layers

[IMP] hardware: Rev D.2
* Remove debug pads
* Reroute Audio pairs from DAC
* Additional Ground VIAs