About nPM1300, how to calculated NTC temperature by measured voltage

[Poki Huang]

Hi 

Could you provide nPM1300 NTC pin inside structure?(pull up resistor value, pull up voltage, others..)

And I want to know how to calculated NTC temperature by measured voltage

For example, if we use 10kohm at 25 degree NTC(B-constant is 3380), and we measured nPM1300 NTC pin (D3 pin) voltage is 0.688V

What is the 0.688V mapping value of ADCNTCRESULTMSB & ADCGP0RESULTLSBS[3:2]?

Thank you

Poki

[Szabolcs]

Hi Poki,

See the following formula on Page 101 of the nPM1300 Product Specification:

You will also need to set the NTC type properly, ADCNTCRSEL=1 in your case.

[Poki Huang]

Hi Szabolcs:

I want to know how to mapping NTC measured voltage to it's register

For example our nPM1300 VDDIO supply is 1.8V

So if we measure NTC voltage is 0.688V, it's mapping register value will be (0.688/1.8)*1024=391 or 392 right?

Thank you

Poki