Why are the capacitors so big, while the transistors are tiny?
In: Technology
A transistor is 3 pieces of specially treated silicon, placed in contact with each other. The size just determines how much energy it can safely handle (and how much it needs), and has little other impact on its function. An npn transistor is an npn transistor, whether it’s a 2n3904 with its own through-hole leads and plastic casing, or a tiny transistor etched onto a silicon wafer in a CPU.
Capacitors store electric charge between two not-quite-touching plates. The amount of charge a capacitor can store, and the voltage it can handle, is determined by the surface area of the plates and how far apart they are. A capacitor that can handle high voltages and hold lots of charge (such as a power supply filter capacitor) generally needs to have a large footprint. Small capacitors can be very small though – solid state drives use a capacitor to store each bit, and a 128GB SSD stores 1.024e12 bits of data, so it’s still possible to fit lots of capacitors into a relatively small area – they’re just maybe not as small as a transistor.
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