Video amplifier chips are used in circuits used to process video signals. They carry performance specifications such as operating temperature, output power, supply voltage, and supply current. Total harmonic distortion (THD) is also an important consideration. With video amplifier chips, TDH is a measure of the purity of a signal. This value is defined as the ratio of the sum of the powers of harmonic components to the power of the fundamental. Bandwidth, another important consideration, refers to the ability of an audio amplifier chip to provide a maximum output voltage swing with increasing frequency.
Integrated Circuit (IC) Package Types Available
Video amplifier chips are available in several integrated circuit (IC) package types. Examples include single in-line package (SIP), dual in-line package (DIP), ceramic DIP (CDIP), and plastic DIP (PDIP). Small outline IC (SOIC), shrink small outline package (SSOP), small outline package (SOP) and chip scale or chip size package (DSP) products are also available. Additional IC package types for video amplifier chips include mini small outline plastic package (MSOP), small outline transistor (SOT), power small outline package (PSOP), thin shrink small outline L-leaded package (TSSOP), quarter size outline package (QSOP), and plastic leaded chip carrier (PLCC).
Selecting Video Amplifier Chips
Selecting video amplifier chips requires an analysis of operation classes. Class A devices feature a design in which the output stage passes current at all times, even when the input stage is idle. By contrast, Class B devices do not pass current when the output device is idle. Class AB video amplifier chips combine Class A and Class B operation. Class C designs are used for radio frequency (RF) transmission while Class D designs have output devices that are switched on and off at least twice per cycle. Class E, Class F, Class G, and Class H video amplifier chips are also commonly available.
Features are an important consideration when selecting video amplifier chips. Some products have an embedded reference voltage or on-chip protection against electrostatic discharge (ESD). Others feature rail-to-rail output or rail-to-rail input. Single supply devices can operate with only one power supply. Video amplifier chips with an embedded control circuit shut down the device when the temperature exceeds a predefined limit. Video amplifier chips with embedded current limiters are also commonly available. In Europe, ICs must meet the requirements of the Restriction of Hazardous Substances (RoHS) directive.