This calculator estimates settling time for a multiplexer by calculating the slower of the two time constants for a cascaded RC network, then computing how many of that time constant must pass before the system will settle to within 1%, 0.1%, 0.01% and 0.001% of its final value.
The calculator also estimates the maximum sampling rate possible for a classic A/D converter with S/H input. The sampling rate is estimated as 1/sqrt( (tsettle+ttransition)2 + tPGA2). This number should be less than the sum of tACQ+tCONV, otherwise the maximum sampling frequency will be limited by the latter. The maximum sampling frequency estimate is shown in megasamples/second to the right of the settling time number.
To use the calculator, enter the multiplexer parameters in RON, CS and CD and the application parameters in RSOURCE, RLOAD and CLOAD. Tabbing from one field to the other updates the tabular display at right, or click "Calculate".