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mx287 what would happen when sample voltage is much larger than VDDIO?

Question asked by h k on Nov 30, 2016
Latest reply on Dec 20, 2016 by h k

I come across 2 questions about the lradc module recently.

1. As mentioned in the title, the iMX28_RM has a reference in chapter 38.2,  page 2662, 

For input channels (other than BATT, 5V, or VDDIO) with signals larger than 1.85
V, the divide-by-two option should be set
(HW_LRADC_CTRL2_DIVIDE_BY_TWO). With the DIVIDE_BY_TWO option
set, the maximum input voltage is VDDIO – 50mv.

 

if our VDDIO is 3.3V,  does that mean the channels like lradc0 can't sample voltage which is larger than 3.3v minus 50mv?

 

2. If I configure the channel 0 as an analog input. So when one conversion is finished, the VALUE field in HW_LRADC_CH0 represents the actual voltage or I have to have it multiplied by voltage/per bit.

 

 

Thanks a lot. 

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