Microelectronic devices, such as transistors, capacitors, and resistors, within an active chip require some protection from the environment. As the schematic diagram suggests, microelectronic devices are typically made from semiconductor materials. Many components of the normal electronic design are available in a microelectronic equivalent. These include transistors, capacitors, inductors, resistors, diodes, and insulators, and conductors can all be found in microelectronic devices. It should be noted here that, as the schematic diagram suggests, microelectronic circuits combine thousands of transistors on a small piece of semiconductor material. Inductors are used in some high-frequency analog circuits but tend to occupy larger chips due to their lower reactance at low frequencies.