Standards - Schematic
- 1 Template
- 2 Component Source
- 3 Style
- 3.1 Grid
- 3.2 Power Net Naming
- 3.3 SPI Net Naming
- 3.4 Port Placement
- 4 Connectors
- 4.1 JST-GH
- 4.2 Molex DuraClick (Deprecated)
- 4.3 Molex Microfit
- 4.4 NGFF B-Key
- 4.5 Mezzanine (Deprecated)
- 5 Decoupling
- 6 Thermistors
Template
All schematic sheets shall use Midnight Sun templates. The title block shall be populated using the relevant sheet parameters.
Component Source
All components used shall be from the team’s A365 library. No components shall be from the Altium content vault, a local library, or any other source.
Style
Grid
All schematics shall be drawn exclusively on a 100 mil grid for neatness. I will be sad if you use a 50 mil grid.
Power Net Naming
Use minimum number of significant digits, always include “V” where the decimal point would go.
Negative nets are prefixed with “N”, positive nets have no prefix.
Ex: 12V, 5V, 3V3, N2V1, 131V
SPI Net Naming
Different manufacturers use many different names for SPI signals. We use MOSI, MISO, SCK, and NSS. This follows STM32 datasheets.
Port Placement
Power ports should always face up (like the letter T), and ground ports should always face down.
Connectors
Below is an overview of the connectors in use.
JST-GH
Starting with MS16 controller boards, we will be moving to the JST-GH series. They are used instead of Microfit due to the size constraints present on the controller board, and wide availability of harnesses and pre-crimped cables. GH Connector | JST Sales America
Molex DuraClick (Deprecated)
Duraclick connectors were used for CAN on controller boards up to MS15. DuraClik Connectors | Molex
Molex Microfit
Use for all board to wire connections other than for CAN. Generally the vertical type is used as is it easier to access. Micro-Fit Connectors | Molex
NGFF B-Key
Starting for MS16, the controller board interface will be the M.2 B-Key interface, with > 2.4mm standoff height between the controller and host boards.
Mezzanine (Deprecated)
For MS15, the controller board interface used 60 pin 0.5mm pitch mezzanine connectors.
Decoupling
IC decoupling shall be achieved by a minimum of one 0.1uF MLCC capacitor per power pin. Additional decoupling shall be added if warranted by the application, such as in high power devices. The datasheet will generally have recommended decoupling schemes. It is acceptable to round decoupling cap values to nicer numbers, ie 0.47uF to 1uF. Be weary of excessive capacitance resulting in inrush current.
Thermistors
The standard thermistor has a 10k value and is situated on the low side.