4-20ma Transmitter

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#1
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I want to know if you happen to know a low cost chip or a discrete solution to achieve a 10bit accuracy,

I love Digital
and you who involved in it!

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Depends what you call low cost?

Microchip and others have serial dacs coupled with an opamp , transistor and and handful of passives wiuld be a start. Compare that to a single chip solution. Factor in b.o.m, pcb area, testing and assembly and see what the result is

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OK,what is your suggestion Microchip part number? and low cost means under 1USD for 100 units.

I love Digital
and you who involved in it!

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I'm quite sure you can use Google as well as i can. Personally, i think your expectations are a bit high - do some research and re-assess them. I think $5 might be achievable for the part cost alone, however at those quantities, the design time is going to swamp any component savings. Even your research time is going to swamp any savings. If i were charging, you've burnt $50 of my professional time just for this.

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Thanks for the info,

I love Digital
and you who involved in it!

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You could replace the DAC with PWM or PDM and a filter.

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10bit resolution is easy to achieve, 10 bit accuracy is a little harder. Using pwm or a dac with the power rail as the reference wont give you 0.1% accuracy. So you'll need a reference. If you use discrete components then you'll need to trim gain and offset. So, once you start crunching the numbers, 10 bit accurcy is going to be a bit more expensive methinks.

And let's not forget temperature- we're talking uA accuracy.