• Home
  • Download PDF
  • Order CD-ROM
  • Order in Print
Figure 3-16.Noninverting configuration
Figure 3-17.Open-loop frequency-response curve

Neets Module 08-Introduction to Amplifiers
Page Navigation
  95    96    97    98    99  100  101    102    103    104    105  
3-25 has been dropped by R2. In either case, the feedback signal (Efdbk) is the ratio of R1 to the entire voltage divider (R1 + R2) multiplied by the output signal (Eout). Mathematically, the relationship of the output signal, feedback signal, and voltage divider is: If you divide both sides of the equation by Eout: By inverting both sides of the equation: Separating the right-hand side: Remember: Therefore, by substitution: You can now see that the gain of the noninverting configuration is determined by the resistors. The formula is different from the one used for the inverting configuration, but the gain is still determined by the values of R1 and R2. BANDWIDTH LIMITATIONS As with most amplifiers, the gain of an operational amplifier varies with frequency. The specification sheets for operational amplifiers will usually state the open-loop (no feedback) gain for d.c. (or 0 hertz). At higher frequencies, the gain is much lower. In fact, for an operational amplifier, the gain decreases quite rapidly as frequency increases. Figure 3-17 shows the open-loop (no feedback) frequency-response curve for a typical operational amplifier. As you should remember, bandwidth is measured to the half-power points of a frequency- response curve. The frequency-response curve shows that the bandwidth is only 10 hertz with this






Western Governors University

Privacy Statement
Press Release
Contact

© Copyright Integrated Publishing, Inc.. All Rights Reserved. Design by Strategico.