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RGB DAC output voltage is wrong #177

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thejpster opened this issue Jan 28, 2024 · 1 comment · Fixed by #178
Closed

RGB DAC output voltage is wrong #177

thejpster opened this issue Jan 28, 2024 · 1 comment · Fixed by #178

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@thejpster
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thejpster commented Jan 28, 2024

On the schematic is says:

Buffer Input = 700 mV = 3.09375 V * R / (1000 + R)

This gives R as 292, rounded to 300 ohm. This is wrong. It should be:

Buffer Input = 700 mV = 3.09375 V * R / (2000 + R)

This gives R as 585 ohm, rounded down to 576 ohm.

On Rev 1.0 and Rev 1.1 you need to replace R510 R610 and R710 with a 585 ohm resistor (or slightly lower is fine)

This mistake means the maximum output voltage is actually ~0.4V and so the picture is a bit dim.

image

image

@thejpster
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IMG_2169

thejpster added a commit that referenced this issue Jan 28, 2024
560R is the best JLCPCB have.
@thejpster thejpster mentioned this issue Jan 28, 2024
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