The characteristics and composition of the integrated operational amplifier

One-piece inductor

1. Features of the integrated operational amplifier

The integrated operational amplifier circuit, referred to as the integrated operational amplifier, is a high performance direct coupled multistage amplifier circuit. It was named because it was first used for signal calculation.

(1) Direct coupling mode, which makes full use of the consistency of the pipe performance, using differential amplifier circuit and current source circuit.

(2) A high-performance amplifier circuit is realized by a complicated circuit because the complexity of the circuit does not bring about the complexity of the process.

(3) Replace passive components with active components, such as replacing large resistors that are difficult to fabricate with transistors.

(4) Use a composite pipe.

Second, the composition of the integrated operational amplifier circuit

If the integrated op amp is seen as a "black box", it can be equivalent to a double-ended input, single-ended output differential amplifier circuit.

The role of the four components of the integrated operational amplifier circuit

Bias circuit: Set the appropriate static operating point for each stage of the amplifier circuit. A current source circuit is employed.
Input stage: Pre-stage, mostly using differential amplifier circuit. Ri is required to be large, Ad is large, Ac is small, and the input end has high withstand voltage.
Intermediate stage: main amplification stage, mostly using common-amplification amplifier circuit. Requires sufficient amplification.
Output stage: power stage, mostly using quasi-complementary output stage. Ro is required to be small and the maximum undistorted output voltage is as large as possible.

Fourth, the voltage transmission characteristics of the integrated operational amplifier