1 / 20

Chapter 10 - B

Chapter 10 - B. Amplifier Frequency Response. Gain Bandwidth Product: Open loop. Gain Bandwidth Product: Open loop. Gain Bandwidth Product: A v to BW. Full BW. No Gain. Open loop A v. Open loop BW. Gain Bandwidth Product: BW to A v. Gain Bandwidth Product: BW vs. A v. f unity.

susan
Download Presentation

Chapter 10 - B

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. Chapter 10 - B Amplifier Frequency Response

  2. Gain Bandwidth Product: Open loop

  3. Gain Bandwidth Product: Open loop

  4. Gain Bandwidth Product: Av to BW Full BW No Gain Open loop Av Open loop BW

  5. Gain Bandwidth Product: BW to Av

  6. Gain Bandwidth Product: BW vs. Av funity 20 dB / dec Av_OL AV = 40 dB  f0 is 2 decade below funity

  7. Gain Bandwidth Product: Example Determine the open-loop BW and the closed-loop BW if R1 = 1 kW and R2 = 20 kW.

  8. Gain Bandwidth Product: Example Determine the unity gain frequency for the following amplifier: BW = 50 kHz, R1 = 1 kW and R2 = 20 kW. Note: The above procedure can be used to estimate the unity gain frequency of an unknown op amp.

  9. Gain Bandwidth Product: Simulation Av = 2

  10. Gain Bandwidth Product: Simulation Av= 10

  11. Small-Signal Rise-Time

  12. Small-Signal Rise-Time: Examples Estimate the BW and unity gain frequency for the following amplifiers.

  13. Slew Rate • The GBW formulas are based on the small-signal ( < 1 Vp) assumption. • For larger signals the current limitation of the op amp can further reduce the BW. • Slew rate is the maximum rate of change of Vout. It has a unit of (V / ms). • Slew rate is the indication of how fast the output can track the change of the input. We can use slew rate to estimate the BW limitation due to large output signal swing.

  14. Slew Rate: Example • An op amp with a slew rate of 0.5 V/ms will take ____________ ms to switch the output voltage from 0 V to 5 V. • An op amp can switch an output voltage from -2 V to +15 V in 25 mS.Its Slew rate = __________

  15. Slew Rate: Example 10-8, p. 269

  16. Full-Power BW fmax • Full-Power BW fmax is the frequency at which the output can barely keep up with the change of the input. • fmax is proportional to the slew rate of the amplifier. • fmax is inversely proportional to the maximum peak voltage of the output signal. • When fmax is greater than the BW calculated from the GBW, we can ignore fmax. • We take the minimum of the two

  17. Full-Power BW fmax • Full-Power BW fmax is the frequency at which the output can barely keep up with the change of the input. • fmax is proportional to the slew rate of the amplifier. • fmax is inversely proportional to the maximum peak voltage of the output signal. • When fmax is less than the BW calculated from the GBW, we can ignore fmax.

  18. Full-Power BW fmaxExample

  19. Full-Power BW fmaxExample For the following amplifier determine the full-power BW for a) Vp_max = 2 V and b) Vp_max = 0.5 V .

  20. Summary • Different amps and op amps • Negative FB • Op amp circuits • Unity gain frequency and GBW • Small-Signal Rise-Time and BW relationship • Slew-rate • Full power BW

More Related