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POWER LIMITS

Operational amplifiers are low-power signal conditioning devices. Usually they will only supply or "source" currents up to about 20mA. They have a continuous power rating of around 500mW Special devices have continuous power ratings of 1 or 2W. To obtain higher powers integrated audio amplifiers can be used. However, such devices do not generally have good linearity.

PHYSICAL, MECHANICAL AND ELECTRICAL DETAILS:

Op-amps are available in a variety of forms. The popular 741 type may be obtained in flat (FA), dual-in-line (DIL) or circular (L type) packages as shown in Fig. 2.1. The pin separation of FA and DIL types is OX', with the rows of connections 0.X apart. In the L circular package the connections form a circle of diameter 0.2X and are 45š apart. Larger packages containing two, four or more op-amps are also available, as shown in the example of Fig. 2.2. Op-amps are usually designed for use with dual voltage power supplies (± 15V is typical). However they can also be operated with single voltage power supplies.

Further details are given in the appendix.