Hi Group,
I am designing an application using the ADC to measure a resistance using a resistive divider. To reduce power consumption when not measuring I need to use a port pin as the supply for the top end of the chain. From the datasheet graph, of high level output voltage vs. output current, I estimate the output impedance to be 40 ohms.
It will have at least a 5K load, so no problems with overload. But I need to make the case in a technical report to correct for the port output impedance in software.Chip is MSP430G2553. I am only taking a small current <500uA at any time, the datasheet is more indicative of heavier loads.
Does anyone have a more definitive output resistance than the 40ohms I estimate from the datasheet graph please?
Thanks,
Rob.