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Modern way to specify values on schematics
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kuon:
Hello,

I thought I would find tons of resources about that, but surprisingly, I found no recommendations.

If this is a sensible topic, I really don't want to start a flame war, so I hope it won't come to that.

I've seen a lot of way to write values in schematics.

For capacitors I've seen 100nF, 0u1F, 0.1uF or even 0.1µF and the same without the unit (100n, 0u1, 0.1u, 0.1µ).

For resistors I've seen 4M75, 4.75M, 4.75MΩ or 100, 100R, 100Ω.

What would be the best modern practice?

As a side question, should resistors and capacitors always have their value visible? I am using a TI chip (BQ25570), which requires 7 resistors to configure the different voltages and the values are not really helpful at a glance (mega ohms), I am wondering if adding a small note with the resistors values and the formula on the schematics wouldn't be better.
ataradov:
I have to review schematics a lot from various sources, so I see a variety of this stuff too.

My personal preference is to always use '.' for decimal separator. And don't use use characters that are hard to type and may not be present in all fonts (µ, Ω).

For resistors - drop Ohm in any variation, so 100 (or 100R), 10K. Full spelling takes a lot of space.

Notes are also a good idea, especially for stuff that was calculated and not just taken from the reference. Atmel/Microchip datasheets include calculations for the load capacitors on the crystals. This does not
get in a way, but helpful when you need it.

Other than this - use flexibility and common sense. I'd rather read a schematic by someone who had freedom to express the design.

One thing that I really like about "modern" designs is lack of standards. This may sound strange, but when you are confined to IEC, GOST, whatever, you sooner or later end up with a mess. Those standards don't deal with complex designs very well.
Benta:
For a schematic, I only use the reference, eg, R1, R5, C2, U3 etc.
For a PCB layout I do the same thing.
I place the component values in the "mouse-over" component description / note / comment  field in the design files (schematic and PCB both).

This gives you a nice clean schematic that's easy to read, and with a click or mouse-over on the component provides additional information.

Full information (such as supplier etc.) is in the BOM.
MarkF:

--- Quote from: Benta on March 03, 2019, 06:33:40 pm ---For a schematic, I only use the reference, eg, R1, R5, C2, U3 etc.
For a PCB layout I do the same thing.
I place the component values in the "mouse-over" component description / note / comment  field in the design files (schematic and PCB both).

This gives you a nice clean schematic that's easy to read, and with a click or mouse-over on the component provides additional information.

Full information (such as supplier etc.) is in the BOM.

--- End quote ---

My paper doesn't have a mouse.  ;D
I like to see the value on the schematic.

And do not use 'm' for micro.  I use 'm' for milli and 'u' for micro.
Gary350z:
I too would like to see the answers to this question.

All through my schooling and work, I've always seen 4.75M. Just since I've been on this forum I've seen the 4M75. Dave has done a video or two on this, and has said that the deciamal point in 4.75M may be become unreadable on a paper schematic, a good point.

I'm in the USA, is it different in other countries.
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