SAADC

[1730143]

Hi Nordic

 I am using saadc example now, my device output voltage range is -4v~4v.

my saadc config:

VDD:            3.3V

Reference:   VDD/4

Gain:            1/4

Mode:           SINGLE_ENDE

i got wrong number when the input voltage is negative and over VDD.

I saw "The AIN0-AIN7 inputs cannot exceed VDD, or be lower than VSS." in nrf52832 product specification.

i want to know is there any way to limit the saadc output to 0 when sample the negative voltage and limit the saadc output to vdd when sample the volatge over vdd?

thanks!

[Turbo J]

Remember to check ABSOLUTE MAXIMUM rating. I recommend using another chip for further tests, as -4V voltage on a pin is likely to cause permanent damage.

Adapting -4 ... +4V signal onto an 0..3,3V ADC input pin usually requires an opamp (or instrumentation amplifier) circuit.

[1730143]

Thanks Turbo J

"Adapting -4 ... +4V signal onto an 0..3,3V ADC input pin usually requires an opamp (or instrumentation amplifier) circuit."

Dose it mean that i can't achieve it with software?