Kinetis MicrocontrollersのトピックRe: [K40DX256VMD10] DAC output voltage range

[K40DX256VMD10] DAC output voltage range

waynejeong — Mon, 03 Jan 2022 11:25:16 GMT

Hello NXP

My customer is considering applying K40DX256VMD10 to develop a his new product.

According to the datasheet low DAC output voltage range is max 100mV.

My customer want to know typical value if it is possible because he will use DAC feature.

May I get the typical value?

Regards

Re: [K40DX256VMD10] DAC output voltage range

bobpaddock — Mon, 03 Jan 2022 13:27:53 GMT

Doesn't that mean that if the DAC output register is set to Zero, there could still be up to 100mV of voltage on the output? In other words there can be a 100 mV offset from the register value. There is likely a graph showing if this offset is linear across the full output range.

Re: [K40DX256VMD10] DAC output voltage range

waynejeong — Tue, 04 Jan 2022 10:45:45 GMT

Hello bobpaddock

Thank you for feedback.

I have more questions.

- there could still be up to 100mV of voltage on the output?

1. Can the DAC output voltage level be 100mv even if I set 0 in the DAC data register?

2. Can the DAC output voltage have 100mV offset even if I calculate DAC output value?

-There is likely a graph showing if this offset is linear across the full output range.

1. I don`t have a graph. Could please let me have graph if you have it?

Regards

Re: [K40DX256VMD10] DAC output voltage range

bobpaddock — Tue, 04 Jan 2022 13:31:09 GMT

Figures 18 and 19 in the datasheet on non-linearities and effects of temperature.

The DAC, nor its reference, are ideal parts.

They will have real-world deviations from the ideal calculated values based on device lot, operating voltage and temperature.

Setting the DAC to Zero may give Zero volts out at room temperature (~25'C) while that same zero setting might give 100 mV out at 85'C.

Re: [K40DX256VMD10] DAC output voltage range

bobpaddock — Tue, 04 Jan 2022 13:53:27 GMT

Analog Devices has a lot of good design information, especially in their Seminar Series.

https://www.analog.com/en/search.html?q=seminar%20dac

and in general:

https://www.analog.com/en/education/education-library.html