Capacitance of capacitor
- A capacitor is a passive electronic component that stores energy in the form of an electrostatic field.
- In its simplest form, a capacitor consists of two conducting plates separated by an insulating material called the dielectric.
- The capacitance is directly proportional to the surface areas of the plates, and is inversely proportional to the separation between the plates.
- Capacitance also depends on the dielectric constant of the substance separating the plates.
The standard unit of capacitance is the farad, abbreviated.
- This is a large unit; more common units are the microfarad, abbreviated µF (1 µF =10-6F) and the picofarad, abbreviated pF (1 pF = 10-12 F).
- Capacitors can be fabricated onto integrated circuit (IC)chips.
- They are commonly used in conjunction with transistors in dynamic random access memory (DRAM).
- The capacitors help maintain the contents of memory. Because of their tiny physical size, these components have low capacitance.
- They must be recharged thousands of times per second or the DRAM will lose its data.
- Large capacitors are used in the power supplies of electronic equipment o fall types, including computers and their peripherals.
- In these systems,the capacitors smooth out the rectified utility AC, providing pure, battery-like DC.