This tool calculates the Rise Time of a simple RC low pass filter network.
- Resistance R (units: milliOhm/Ohm/kilOhm/megOhm)
- Capacitance C (units: Farad/milliFarad/microFarad/nanoFarad)
tr = 2.197*RC
Rise time in this formula represents the time it takes to get from 10% to 90%.
An RC low pass filter with R = 1 ohm and C = 1 microfarad has a rise time of 2.2 microseconds.
 Rise Time of a Single Stage Low Pass RC Network on Wikipedia