DAC K70

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DAC K70

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punyatagayatri
Contributor II

Is there a way to provide external reference for DAC for K70 Freescale Kit.Pls help

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adriancano
NXP Employee
NXP Employee

Hi,

According to the section 3.7.3.3 of the K70 reference manual the DAC has 2 reference options:

  • VREF_OUT is connected to DACREF_1
  • VDDA is connected to DACREF_2

The VREF_OUT can be used internal and external and it is the output of the Voltage reference module. According to the data sheet the value does not exceed 1.2376 V (refer to the VREF full-range operating behaviors section in DS)

vrefout.jpg

When used as the DACREF_1 is connected internally to the ADC module. Therefore is not possible to connect an external reference to the DAC module.


Hope this information can help you

Best Regards,
Adrian Sanchez Cano
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punyatagayatri
Contributor II

I understand we cant provide external ref to DAC. Am I correct?

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adriancano
NXP Employee
NXP Employee

Yes, you are correct

Regards,

Adrian

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punyatagayatri
Contributor II

We took out L6 just to see what happens on DAc kit and if we can hook up wire to provide reference externally.I am not sure if this is good approach but before I could plug in external voltage, we observed that on plugging out L6, we get voltage of around 1.89 at VDDA point.I thought it would be approx zero.I'm unable to make out from where is this voltage appearing here....

DAC.jpg

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