chapter 12 _Signal generators and waveform-shaping circuit

Oscillating frequency is the one that the phase shift

This preview shows page 16 - 30 out of 40 pages.

Oscillating frequency is the one that the phase shift of the RC network is 180 0
Image of page 16

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits The Phase-Shift Oscillator A practical phase-shift oscillator with a limiter for amplitude stabilization.
Image of page 17
SJTU Yang Hua Microelectronic Circuits The LC-Tuned oscillator Colpitts Oscillator A parallel LC resonator connected between collector and base. Feedback is achieved by way of a capacitive divider Oscillating frequency is determined by the resonance frequency. ) ( 1 2 1 2 1 0 C C C C L + = ϖ
Image of page 18

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits The LC-Tuned oscillator Hartley Oscillator A parallel LC resonator connected between collector and base. Feedback is achieved by way of an inductive divider. Oscillating frequency is determined by the resonance frequency. ) ( 1 2 1 2 1 0 C C C C L + = ϖ
Image of page 19
SJTU Yang Hua Microelectronic Circuits Crystal Oscillators A piezoelectric crystal. (a) Circuit symbol. (b) Equivalent circuit.
Image of page 20

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits Crystal Oscillators Crystal reactance versus frequency (neglecting the small resistance r , ). A series resonance at A parallel resonance at s s LC 1 = ϖ ) ( 1 p s p s p C C C C L + = ϖ
Image of page 21
SJTU Yang Hua Microelectronic Circuits Homework: June 12th, 2008 12.13;12.14
Image of page 22

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits Bistable Circuit -- three basic factors The output signal only has two states: positive saturation(L + ) and negative saturation(L - ). The circuit can remain in either state indefinitely and move to the other state only when appropriate triggered .(threshold voltage) The direction of one stage moving to the other stage. A positive feedback loop capable of bistable operation.
Image of page 23
SJTU Yang Hua Microelectronic Circuits Bistable Circuit The bistable circuit (positive feedback loop) The negative input terminal of the op amp connected to an input signal v I . β o o v R R R v v = + = + 2 1 1
Image of page 24

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits Bistable Circuit The transfer characteristic of the circuit in (a) for increasing v I . Positive saturation L + and negative saturation L - β + = L V TH
Image of page 25
SJTU Yang Hua Microelectronic Circuits Bistable Circuit The transfer characteristic for decreasing v I . β - = L V TL
Image of page 26

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits Bistable Circuit The complete transfer characteristics.
Image of page 27
SJTU Yang Hua Microelectronic Circuits A Bistable Circuit with Noninverting Transfer Characteristics 2 1 1 2 1 2 R R R v R R R v v o I + + + = +
Image of page 28

Subscribe to view the full document.

SJTU Yang Hua Microelectronic Circuits A Bistable Circuit with Noninverting Transfer Characteristics The transfer characteristic is noninverting.
Image of page 29
Image of page 30
You've reached the end of this preview.
  • Fall '10
  • ChengJianping
  • Oscillators, Electronic oscillator, Multivibrator, Microelectronic Circuits, SJTU Yang Hua

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern