PROJECT TITLE : CMOS STAGE RING OSCILLATOR USING 0.25u CMOS TECHNOLOGY


NAME:AAKASH K 
COLLEGE:CAMBRIDGE INSTITUTE OF TECHNOLOGY K R PURAM BENGALURU 
EMAIL ID:aakash.18ec185@gmail.com



PROJECT ABSTRACT

Ring oscillator is one of the important component used in Integrated chip(IC).Ring oscillator circuits are a valuable test structure for determining the feasibility and success of an integrated circuit process fabrication sequence.One of the most useful results obtainable from a ring oscillator test structure is the delay time per gate. This information is especially important for
successful design of high speed clock circuits. Oscillator has 3 inverters then it is called a three-stage ring oscillator.The number of inverter stages in this oscillator mainly depends on the frequency which we want to generate from this oscillator



CIRCUIT DETAILS 

CMOS 3 stage ring oscillator comprises of an odd number of CMOS inverters. The output of each inverter is used as input for the next one.
The last output is fed back to the first inverter. Because of the delay time of each stage the whole circuitspontaneously starts oscillating at a certain frequency.A ring oscillator can be made with a mix of inverting and non-inverting stages,provided the total number of inverting stages is odd.Ring oscillator consists of PMOS and NMOS and capacitors C1,C2,C3. NMOS is constructed with the ntype source and drain and a p-type substrate, while PMOS is constructed with the p-type source and drain and an n-type substrate. PMOS device is connected tothe supply voltage (+VDD) and NMOS device is alsoconnected with ground (GND) to the circuit.Ring oscillator circuit is connected with a DC source



INSTALLATION OF eSIM TOOL

VSD team shared us a link to download the eSIM Tool which is used to stimulate the circuits
and also shared the sky130 library files.it was very difficult to understand the sky library files with zero basic knownledge of the library files



CONSTRUCTION OF CIRCUIT 

1.Create a project (without using any space in between)
2.eSIM will open schematic
3.Circuits are placed by connecting with proper power supply and GND
4.Annoate and check for errors
5.Click on Genarate netlist and edit those code and some sky libary files and voltage values and .tran values to it
6.Waveforms will be generated 



WAVEFORMS OBTAINED

PROBELMS FACED
1.Unable to understand the skylibrary files
2.Some of the Components were not included in the components list 
3.We are not able to get the proper or accurate waveforms