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For same input parameters (resolution and sample rate) are costly DAC chips meant to produce signals closer to real world analog than cheaper ones?

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    \$\begingroup\$ I'm voting to close this question as off-topic because it can be answered by reading the datasheets. \$\endgroup\$ Jul 1, 2017 at 17:23
  • \$\begingroup\$ There are other factors that influence the selling price of an IC. \$\endgroup\$ Jul 1, 2017 at 19:17

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The resolution may be the same spec, but the "noise" will be different; that means the step-size will vary away from ideal on the cheaper DACs.

A 12 bit DAC, promising to cover 0.0 volts to 4.096 volts in precise 1.0000 millivolt steps, is a good test case. Or even 8 bit DACs.

Read the datasheets. You'll also find the cumulative errors, the sum of those steps, will be larger on the cheaper DACs. Thus at mid scale, where you expect 2.048 volts, you likely will be nowhere near 2.048 volts. Additionally, the codes right before and right after 2.048 likely will show HUGE errors (the dreaded mid-scale nonlinearity).

The two specs of interest are DNL and INL.

DNL is differential nonlinearity, describing the finegrain wander of Vout (or Iout) away from ideal 1.00000 milliVolt steps.

Integral nonlinearity described the cumulative wander of Vout away from ideal.

Often the DACs are trimmed for ZERO and for FULLSCALE accuracy. That will be spec'd (if not, you should not consider that DAC for use). The INL describes the DAC output error, worst case, at voltages other than exactly ZERO and exactly FULLSCALE.

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If those parameters are the same then yes, they will produce the same "quality" of output signal. However, if there is a price difference, you can wonder why. Many parameter can influence chip cost:

  • Sustainability, it's possible that some chip has a shorter time than other one. This will automatically increase the cost.
  • Reliability, some chip has some build in protection for temperature change, emc, power supply quality or variation.
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