Radio receiver support worldwide radio band requirements, including frequency modulation (FM), FM radio data system (RDS), amplitude modulation (AM), long wave (LW), short wave (SW), and weather bands. These integrated circuits (ICs) are designed to receive radio signals for processing and subsequent conversion into a form useful to listeners. Radio receiver ICs are relatively small, but are functionally similar to traditional radio receivers. In electronics, a receiver is a device that converts radio waves into intelligible sounds or other perceptible signals. These radio waves represent a distinct part of the electromagnetic spectrum. There are many different types of radio receiver ICs. FM devices use frequency modulation (FM), a technique that causes the instantaneous frequency of a sine-wave carrier to depart from the center frequency by an amount proportional to the instantaneous value of the modulating signal. AM radio receiver ICs are also available. These devices use amplitude modulation (AM), a technique that causes the baseband signal to vary the amplitude or height of the carrier wave to create the desired information content. Radio receiver ICs for specific applications such as television, shortwave radio, and communications are also available. Radio receiver ICs differ in terms of product specifications such as logic family. Choices include bipolar CMOS (BiCMOS), a silicon-germanium technology that combines the high speed of bipolar TTL with the low power consumption of CMOS. Transistor-transistor logic (TTL) and related technologies such as Fairchild advanced Schottky TTL (FAST) use transistors as digital switches. Another logic family, complementary metal-oxide semiconductor (CMOS), uses a combination of p-type and n-type metal-oxide-semiconductor field effect transistors (MOSFETs) to implement logic gates and other digital circuits. Radio receiver ICs that use BiCMOS II technology are also available. Some radio receiver ICs use AM up-conversion and FM down-conversion as a type of filter. For gain and offset compensation, an integral digital-analog-converter (DAC) may be used. Radio frequency (RF) automatic gain control (AGC) is programmable in steps of one or two decibels (dB). Radio receiver ICs are also characterized by low current consumption, which helps to keep power dissipation in the tuner within an acceptable range. Specialty radio receiver ICs are also commonly available.