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.