2017-03-11 Board Review Notes

Owned by Former user (Deleted)
Last updated: Sept 20, 2018 by Karl Ding

Participants

Pre-Charge Controller

SR latch initialization

  • Output capacitor

  • 2-inverter implementation

  • MUX output driving select line (MUX latch itself)

PMOS vs. NMOS -> Rdson losses

PCB

  • Move resistors away from edge

  • Thin out traces between resistors

  • Replace acute angles with T-junctions (i.e. 12V line on the right of the board)

  • Parts can be lined up better/silkscreen more clear

  • 12V too close to pin 9 of U2

  • Thicken traces for HV section on bottom

  • Move traces away from edge

BMS_Interface

  • 1mA biasing current (agree on biasing resistors)

  • Mode 3 for SPI

  • Source 150A current transducer

  • Isolation for BMS carrier board (common mode choke) -> safe rating of 200V

  • Moar LEDs

  • Low offset op amp

Telemetry

Schematic:

  • BergStak pinout does not match Controller Board pinout
  • Needs bulk capacitors
  • Consider local 3V3 regulator instead of using Controller Board regulator - i.e. place power supply on board

PCB:

  • C1, C2, C5, C6 are 0603 metric (0201 imperial), not 0603 imperial
  • MicroSD should be at the edge of the board with the opening of the slot facing out - currently the MicroSD cannot be inserted
  • Component placement of R1, R2, C3, C4 can be more organized to reduce vias and trace lengths
  • Vias and trace lengths should be reduced in general
  • 3V3 can be implemented using a polygon instead of daisy chained traces
  • Try not to route traces in between pads if it is avoidable


For everyone:

Pull back ground plane from the edges!!!