The second part is a basic “ Differential Amplifier”. The output of both the amplifier is connected with three resistors. Both of them are provided with negative feedback as it stabilizes the circuit more. Two standard operational amplifiers are connected, as shown in the amplifier circuit figure. The first part is “Two input and two output”. We can segregate the instrument amplifier design into two-part. They are connected in a specific order to build an instrumentation amplifier. Instrumentation Amplifier DesignĪn instrumentation amplifier is a combination of 3 typical amplifiers. The output of the 3 rd amplifier is Vout. The output of the Amplifier -1 is the Vo1, and that of amplifier -2 is Vo2. The current through the R4, R3, and R4 branch is I. The voltage at A and B terminals are VA and VB, respectively. Carefully observe the picture as we are going to reference the photo for the rest of the article. The below image represents a typical circuit diagram of an instrumentation amplifier. As instrumentation amplifiers are consisting of 3 amplifiers, they are often called three op-amp amplifier. All three amplifiers work as a differential amplifier, and all of them are connected with negative feedbacks. Two of them are used in a single-stage, whereas the other is used to separate a stage. 3 Op-Amp Instrumentation AmplifierĪ typical Instrumentation amplifier consists of 3 regular op-amps. This article will discuss in detail about circuit, design, formulas, and equations related to the Instrumentation amplifier. So, we can say that it tries to possess most of the characteristics of an ideal op-amp.Īn instrumentation amplifier is often called as In-Amp or InAmp. Instrumentation amplifier provides higher gain, high CMRR (common-mode rejection ratio) and high input impedances. Frequently Asked Questions Introduction to Instrumentation AmplifierĪn instrumentation amplifier is a particular type of amplifier which is derived from meeting some specific purposes.Instrumentation Amplifier for current sensing.
Instrumentation Amplifier noise analysis.Instrumentation Amplifier vs Operational Amplifier.Instrumentation Amplifier transfer function.Instrumentation Amplifier output waveform.Instrumentation Amplifier offset voltage.Introduction to Instrumentation Amplifier.