Which among the following are the major responsible reasons for the cause of 'Slew Rate'?
Q. Which among the following are the major responsible reasons for the cause of 'Slew Rate'?- Published on 26 Oct 15a. Current limiting
b. Saturation of internal stages due to application of high frequency & amplitude signal
c. Both a & b
d. None of the above
ANSWER: Both a & b
Slew rate is the maximum rate of change of output voltage with respect to time. For an instance, suppose that if the slew rate appears to be 1V/microseconds, then the output rises or falls at the speed rating of 1V/microseconds. Slew rates are also referred as output voltage swing as a function of frequency or as a voltage follower large signal pulse response. Also, the slew rate has an inverse relation to temperature. As the temperature increases, the slew rate decreases.
Since slew rate belongs to the category of large signal phenomenon, current limiting and the saturation of intrinsic stages of op-amp leads to reasons of slew rate to greater extent. However, when a frequency & amplitude signal is applied, the resulting current is also at extravagant level so as to charge the network of capacitance compensation. It is obvious that charging & discharging of capacitor needs some finite amount of time and therefore, the internal capacitors are solely responsible in preventing the output voltage to respond instantaneously to the fast varying input.
Hence, capacitor charging rate affects the current limiting in slew rate, which indicates that the voltage across the capacitor is nothing but the output voltage.
