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TMS320F28377S-Q1: ADC measurement and GPIO output on the same pin

Part Number: TMS320F28377S-Q1

Does anybody have any experience in using exactly the same pin as an ADC input and a communication GPIO (out), as two alternating functions? Would it be possible to switch between them during operation? If so, can the GPIO drive the small capacitor (1 - 4.7 nF) that is typically needed for an SAR ADC? The communication speed can be slow (9600 or so).

Many thanks!

  • Cezary,

    Are you referring to using the DACOUTA/B/C to behave like a GPIO signal?  There is no risk to the ADC, but you would need to remove whatever input signal is driving the ADC to avoid contention externally.  The DACOUT pins have a 50kOhm PD so you would need to factor that into the rise/fall time with the external capacitor.

    Let me know if this is what you were thinking of, or something else.

    Best,

    Matthew