Ring oscillator.pptx

Implementation of ring oscillator

1. Ring oscillator Presented by: Jai Shivam Chaudhary Reg no.-12018935

2. What is oscillator ??? An oscillator is used to generate a signal which has a specific frequency, and these are useful for synchronizing the computation process in digital systems. It is an electronic circuit that produces continuous waveforms without any input signal. The oscillator converts a dc signal into an alternating signal form at the desired frequency. An oscillator is a mechanical or electronic device that works on the principles of oscillation :   a periodic fluctuation between two things based on changes in energy .

3. Type of Oscillator O scillatorscan broadly be classified into two main categories – Harmonic Oscillators (also known as Linear Oscillators) and Relaxation Oscillators. In a harmonic oscillator , the energy flow is always from the active components to the passive components and the frequency of oscillations is decided by the feedback path I n a relaxation oscillator , the energy is exchanged between the active and the passive components and the frequency of oscillations is determined by the charging and discharging time-constants involved in the process. The ring oscillator is a member of the class of  time-delay oscillators, which Relaxation oscillator . A time-delay oscillator consists of an inverting amplifier with a delay element between the amplifier output and its input.

4. About Ring oscillator The definition of the ring oscillator is : A n odd number of inverters are connected in a series form with positive feedback & output oscillates between two voltage levels either 1 or zero to measure the speed of the process. The number of inverter stages in this oscillator mainly depends on the frequency which we want to generate from this oscillator. The output of the last inverter is connected to the first inverter; the name “ring” oscillator comes from this detail It needs only a power supply to operate and then oscillations start thereafter on its own USING GATES Using Transistor

5. About Project In this project I have designed three ring oscillator  3-Stage ring oscillator  5-stage ring oscillator  9-stage ring oscillator The mentioned n-staged oscillators are designed and implemented using inverters at both pmos and nmos and Logic Gate. Ring oscillator uses an odd number of inverters to achieve more gain than a single inverting amplifier. The inverter gives a delay to the input signal and if the numbers of inverters are increases then oscillator frequency will be decreased. So the desired oscillator frequency depends on the number of inverter stages of the oscillator.”

6. 3-Stage oscillator The 3-stage oscillator has three inverters that are connected in the form of series with a positive feedback system. So the oscillations & the gain of the system are sufficient.

7. 5-Stage Oscillator In this ring oscillator we have used 5 inverter and output of last inverter is connected to first inverter input.

8. 9-Stage Ring oscillator In this ring oscillator we have used 9 inverter and output of last inverter is connected to first inverter input. The s frequency of oscillation formula for this oscillator is T = time delay for single inverter n = number of inverters in the oscillator

9. Waveform

10. DEADZONE This is the part where frequency loop does not occur for a while ,this says about the change in state from previous output where the loops does not occur as it require time to get the present state.

11. Final output and results Average Power Average delay S.no Using GATES Using PMOS&NMOS 3-Stage oscillator 61.37*10^-6 55.95*10^-6 5-Stage oscillator 65.45*10^-6 20.02*10^-6 9-Stage oscillator 9.628*10^-3 7.268*10^-3   3-Stage oscillator 5-Stage oscillator 9-Stage oscillator 9.6ps 10.23ps 11.43ps

12. Application of Ring Oscillators A few  applications of this oscillator  will be discussed here. They are, These are used to measure the effect of voltage and temperature on an  integrated chip . During wafer testing, these oscillators are preferred. In frequency synthesizers these oscillators are applicable. For data recovery purposes in serial data communications, these oscillators are useful.

13. CONCLUSION