Enter all but one of the variables (C, I, ΔV, f) into the calculator to determine the value of the bypass capacitor; this calculator can also evaluate any of the variables given the others are known.
Bypass Capacitor Formula
The following formula is used to calculate the value of a bypass capacitor:
C = (I * ΔV) / (f * ΔV)
Variables:
- C is the value of the bypass capacitor
- I is the current flowing through the circuit
- ΔV is the desired change in voltage
- f is the frequency of the signal
To calculate the value of the bypass capacitor, multiply the current flowing through the circuit by the desired change in voltage. Divide the result by the product of the frequency of the signal and the desired change in voltage.
What is a Bypass Capacitor?
A bypass capacitor is an electronic component that conducts an alternating current (AC) around a component or group of components within a circuit. It is typically used in electronic circuits to remove or ‘bypass’ unwanted noise or interference. The bypass capacitor works by providing an alternative path for the AC signal, which could otherwise interfere with the operation of the circuit. It is usually placed between the power supply and ground in a circuit, and is often a small value capacitor that can effectively short out, or bypass, high-frequency noise signals. The bypass capacitor essentially acts as a kind of filter, allowing the desired direct current (DC) signals to pass through while diverting the unwanted AC signals. This helps to maintain the stability and efficiency of the circuit.
How to Calculate Bypass Capacitor?
The following steps outline how to calculate the Bypass Capacitor.
- First, determine the input voltage (Vin) in volts.
- Next, determine the output voltage (Vout) in volts.
- Next, determine the load current (Iload) in amperes.
- Next, determine the desired ripple voltage (Vripple) in volts.
- Next, gather the formula from above = C = (Iload * Vripple) / (Vin – Vout).
- Finally, calculate the Bypass Capacitor.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
input voltage (Vin) = 12V
output voltage (Vout) = 5V
load current (Iload) = 0.5A
desired ripple voltage (Vripple) = 0.1V
