Post on 28-Dec-2015
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Number Controlled Oscillator
Open Pyxis Schematic and Design the Schematic for NCO as shown in the
figure.
PMOS
Width : 1.5 micron
Length : 0.25 micron
NMOS
Width : 1.5 micron
Length : 0.25micron
Note : You can also refer the document you have sent me for drawing the
schematic of NCO.
Note : Set ASIM_MODEL to P (for pmos device) and N (for nmos device)
1. Create a Symbol for the Schematic.
2. Open a new schematic and invoke the created symbol and complete
the design for simulation as in figure.
Voltage Pulse set to 5V
DC Voltage Set to 5 V
Go for simulation. Add the Model files, set the Analyses and add the
probes (to check output waveform)
After the Simulation we will proceed for Layout. Change
ASIM_MODEL to PMOS (for pmos device) and NMOS (for nmos
device).
After the Simulation is completed for schematic. We proceed for layout.
The method used here is SDL (Schematic Driven Layout).
Ensure the ASIM_MODEL names are changed accordingly.
Select all the PMOS devices which have common Source (VDD) and
instantiate them onto the layout window.
Similarly instantiate all the NMOS devices which are connected to common
Source (ground).
There are two more devices remaining a pmos and an nmos inbetween. Select
them individually and instantiate them onto the layout.
Flip the two separate devices (pmos and nmos) and arrange them accordingly.
Instantiate all the ports present in the design.
Complete the layout by connecting all the terminals and ports as shown in the
figure.
Finally, Physical verification using calibre and back annotate the design.
Note : By instantiating the devices which have a common source, we have
drain and source sharing between two devices and hence u see all 11
devices as a single device.