MM9Z1_638, Voltage measurement by Vsense0 input

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MM9Z1_638, Voltage measurement by Vsense0 input

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Boris_Bloxsberg
Contributor III

Hi,

I want to measure a temperature by a voltage divider and the VSENSE0 input but I´m not sure about the supply voltage of the voltage divider. 

My questions are:

- Is the vsense0 input an "absolute" input? 

- Is the vsens0 an "relative" input and what is the reference voltage?

I just found the following picture in the manual (page ), but no Vref value.

Boris_Bloxsberg_0-1663937073550.png

Regards

 

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1,006 次查看
TomasVaverka
NXP TechSupport
NXP TechSupport

Hi,

There is no need to know the Vref value of VSENSE.

The measured selected (based on VSSEL and VSEx bits of the GPIO_VSENSE register) voltage can be calculated as follows:

1. VSENSEx: V = ACQ_VOLT[15:0] x VSxRO

pastedImage_29.png

2. PTBx: V = ACQ_VOLT[15:0] x PTB0-4VRES

pastedImage_28.png

 

Best regards,

Tomas

 

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1,003 次查看
Boris_Bloxsberg
Contributor III

Dear Tomas,

 

thanks for the reply. I know for the PTBX inputs I don´t need to know the supply voltage, because the input voltage is supplied/generated by vdda (relative input). The questions is, what suppy voltage could I use for the Vsense0 input with a input range of 0 to 10Volts. Do you mean it doesnot matter because its an absolut input?

regards

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TomasVaverka
NXP TechSupport
NXP TechSupport

Hi,

Table 118.JPG

Best regards,

Tomas

1,007 次查看
TomasVaverka
NXP TechSupport
NXP TechSupport

Hi,

There is no need to know the Vref value of VSENSE.

The measured selected (based on VSSEL and VSEx bits of the GPIO_VSENSE register) voltage can be calculated as follows:

1. VSENSEx: V = ACQ_VOLT[15:0] x VSxRO

pastedImage_29.png

2. PTBx: V = ACQ_VOLT[15:0] x PTB0-4VRES

pastedImage_28.png

 

Best regards,

Tomas