1 / 7

Operational Amplifiers

Operational Amplifiers. A brief introduction. Op-Amp Introduction. Need exists for a circuit element that can perform: Add, subtract, multiply, divide, differentiate, integrate Evolved from Analog Computers Op-Amp properties

trella
Download Presentation

Operational Amplifiers

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Operational Amplifiers A brief introduction BAE 5413

  2. Op-Amp Introduction • Need exists for a circuit element that can perform: • Add, subtract, multiply, divide, differentiate, integrate • Evolved from Analog Computers • Op-Amp properties • Single building block which can be assembled into above functions by adding passive components (R,L,C) • Inexpensive (used in high volume) • Compact • Op-Amp analysis • Use assumptions of “Ideal Op-Amp” to allow low frequency performance to be approximated • Typically have near ideal characteristics but frequency response of an integrator (G(s) = 1/ts). (Otherwise, the high bandwidth would be impossibly difficult to manage.) BAE 5413

  3. Ideal Op-Amp Assumptions • Differential function • Vout = A•DV • Infinite • Intrinsic gain: A =  • Input impedance: Zin =  • Bandwidth: Vout  f(w) • Zero • Input offset voltage: Vio= 0 for Vout+ Vio= A•DV • Input impedance: Zout = 0 BAE 5413

  4. Inverting Amplifier • Consider the circuit configuration to the right • Assuming intrinsic gain of the op-amp is very large for the frequency of interest: • Voutis finite and typically within +15 to -15 V implying DV is very small • Assuming ib is very small given the intrinsic input impedance is very large, Vb must be very small BAE 5413

  5. Inverting Amplifier • Amplifier performance is a function of external components only for ideal assumptions • Input and output impedances of the amplifier can be calculated as approximately: BAE 5413

  6. Non-Inverting Amplifier BAE 5413

  7. Non-Inverting Amplifier • Input and output impedances can be calculated as approximately: BAE 5413

More Related