EMS Power and Ground Reference Design

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Fred
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EMS Power and Ground Reference Design

Post by Fred »

This belongs in another thread, but I'm unsure which one and have no time to check, so here is a new, and possibly temporary one.

Power interface routing and connection considerations:
  • Signal/CPU ground separate, preferably 2 pins and grounded at block or battery.
  • Low side power driver ground separate, preferably 2 (or more) pins and grounded at block or battery.
  • CPU/5Vref raw power input (6.25V - 24.5V, nominal 14.4V) separate, preferably on 2 pins, powered from battery as directly as possible. Regulator(s) run from this.
  • High side power drivers/transient suppression power input (6.25V - 24.5V, nominal 14.4V) separate, preferably on 2 (or more) pins, powered from battery as directly as possible. Power is both drawn from and returned to this feed.
  • Battery Voltage reference power input (6.25V - 24.5V, nominal 14.4V) separate, powered from battery as directly as possible. Divider network and signal conditioning scales to 5v and protects CPU input and smooths signal as appropriate (tunable). Resistor values should be 1k and 3.9k and of very tight tolerance construction.
  • Signal/CPU ground should be large gauge and CPU and 5Vref raw power input should be small gauge.
This can be discussed, if you wish, but this is more or less how approved FreeEMS boards will be connected and designed.

Fred.
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jharvey
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Re: EMS Power and Ground Reference Design

Post by jharvey »

Several good practices can be found here as well.

http://opencircuits.com/Techniques
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