For example, the signal source is a voltage source or a current source the nature of the load, and whether the output voltage and current of the integrated op amp meet the requirements operating voltage range, power consumption, and volume of the integrated op amp.įigure 1: Using Operational Amplifier as a Comparator When selecting an integrated op amp, some factors should be considered in addition to the figure of merit coefficient K. Therefore, for circuits that amplify AC signals such as audio and video, op amps with large SR are better for circuits that handle weak DC signals, op amps with high accuracy are more suitable (both offset current, offset voltage and temperature drift are relatively small).
The smaller the Iib and VOS values, the better the DC characteristics of the op amp. The larger the value, the better the AC characteristics of the operational amplifier The input bias current of the amplifier is lib, the unit is nA VOS is the input offset voltage in mV. Generally, the merit coefficient K is used to measure the excellent degree of integrated operational amplifiers, which is defined as: where SR is the slew rate and the unit is V / ms. The evaluation of integrated op amps depends on their overall performance. For example, LM324 and LF347 always integrate four op amps together in a circuit. When using multiple op amps in a system, use as many op amp integrated circuits as possible. Where there are no special requirements, try to use a universal integrated operational amplifier as much as possible, which can reduce costs and easily replace. In various systems, because of different application requirements, the performance requirements of operational amplifiers are also different. Integrated operational amplifiers are one of the most widely used devices in analog integrated circuits. Now they widely used in the electronics industry, regarded as precision AC and DC amplifiers, active filters, oscillators and voltage comparators. Its output signal can be input signal addition, subtraction or differentiation, integration, etc, which early used in analog computers to do mathematical operations. When you apply them in the circuits, you must know their basics and functions.Īs for the function of the operational amplifier, in electronic circuit, it is usually combined with a feedback network to form a certain functional module, with a special coupling circuit and feedback. The operational amplifier is arguably the most useful single device in analog electronic circuitry.