Hello all!
I could not figure out yet why it is recommended to use different values of capacitors for decoupling in any (analogue/digital/mixed-signal) system; be it the decoupling of power pins, or the reference pins or any other pin.
For suppressing transients, capacitors are needed, bypassing that pin to ground. Why is it recommended to use different values of capacitors, some small some large, for the decoupling? Isn't it so that the higher the decoupling capacitance, the more powerfully it suppresses the transients, along with RF and other noise? Wouldn't it be better that instead of instead of using different values of decoupling capacitors, we use all the capacitors of the same (highest) value, which would have a higher equivalent capacitance on the same amount of (precious) board space, which would ultimately lead to better transient performance per unit of board area?
It would be really appreciable if someone could explain why these different values are used for decoupling, and what should be these values in a typical system?
Thanks in advance.
I could not figure out yet why it is recommended to use different values of capacitors for decoupling in any (analogue/digital/mixed-signal) system; be it the decoupling of power pins, or the reference pins or any other pin.
For suppressing transients, capacitors are needed, bypassing that pin to ground. Why is it recommended to use different values of capacitors, some small some large, for the decoupling? Isn't it so that the higher the decoupling capacitance, the more powerfully it suppresses the transients, along with RF and other noise? Wouldn't it be better that instead of instead of using different values of decoupling capacitors, we use all the capacitors of the same (highest) value, which would have a higher equivalent capacitance on the same amount of (precious) board space, which would ultimately lead to better transient performance per unit of board area?
It would be really appreciable if someone could explain why these different values are used for decoupling, and what should be these values in a typical system?
Thanks in advance.