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swty todd
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what is the difference between opamp & differential amplifier?
An opamp, or operational amplifier, is a type of electronic device that amplifies the difference between two input voltages. On the other hand, a differential amplifier amplifies the difference between two input voltages while rejecting any common-mode signal present on both inputs. In other words, an opamp amplifies the voltage difference between two inputs, while a differential amplifier amplifies the voltage difference between two inputs while canceling out any common-mode signals.
The input and output signals of an opamp and a differential amplifier are similar in that they both have two inputs and one output. However, the input signals of an opamp are typically single-ended, while the input signals of a differential amplifier are differential. Additionally, the output of a differential amplifier is also differential, while the output of an opamp can be either single-ended or differential.
Opamps are commonly used in amplifiers, filters, and signal processing circuits. They are also used in feedback systems, oscillators, and instrumentation circuits. Differential amplifiers are commonly used in applications where high common-mode rejection is required, such as in instrumentation and communication systems. They are also used in analog-to-digital converters and balanced audio systems.
The internal circuitry of an opamp typically consists of a differential amplifier stage, followed by a gain stage and an output stage. On the other hand, the internal circuitry of a differential amplifier typically consists of two differential amplifier stages, one for each input, followed by a differential to single-ended converter and an output stage. Additionally, opamps often have additional circuitry for features such as feedback and compensation, which are not present in differential amplifiers.
The gain of an opamp is typically very high and can be easily adjusted using external components, while the gain of a differential amplifier is fixed and is determined by the ratio of the feedback resistors. The input impedance of an opamp is also very high, while the input impedance of a differential amplifier is typically lower due to the presence of feedback resistors. However, the input impedance of a differential amplifier is still much higher than that of other types of amplifiers, such as single-ended amplifiers.