Power Switches

Power switches are simply transistors that are designed to connect a load to a power supply.  Different types of transistors can be used as a power switch.  Some general characteristics of a power switch are very low on resistance, built in flyback diodes, and fast switching speed.  Two basic categories of power switches are high side (connected to the positive supply and the load) and low side (connected to the negative, or ground, supply and the load).  A power switch IC may contain a single switch, multiple switches of the same type, or multiple switches of different types.  Since power switches typically consume a significant amount of power, accounting for thermal resistance and analyzing heat flow are critical when designing a circuit that utilizes these components.