
Circuit implemented
	2 - INPUT CMOS NAND GATE
 
Softwares/libraries used
	1) eSim
	2) ngspice
	3) Skywater SKY130

Circuit details
	The circuit is designed using 2 PMOS transistors and 2 NMOS transistors. The PMOS are connected in parallel 
and NMOS are connected in series. vdd = 1.8 V. The inputs are vin1 and vin2 which are pulses. The pulsing characteristics 
of vin1 and vin2 are as follows. The initial values of vin1 and vin2 are 0 V. The pulsed value of vin1 and vin2 are 1.5 V and
 1 V respectively. The pulse width of vin1 and vin2 are 5 microseconds and 10 microseconds respectively.
 The period of vin1 and vin2 are 10 microseconds. The output is obtained from the output port.


Steps
	The circuit schematic is designed using eSim.
	The electronic rules check was performed and the SPICE netlist is obtained.
	The SPICE netlist is modified and mosfets from sky130 are included.
	Proper command lines are included.
	The modified file is saved.
	The file is opened using ngspice to see the various plots.

SPICE Netlist from eSim

* C:\Users\haris\eSim-Workspace\Esim_marathon\Esim_marathon.cir

* EESchema Netlist Version 1.1 (Spice format) creation date: 6/29/2021 10:55:28 PM

* To exclude a component from the Spice Netlist add [Spice_Netlist_Enabled] user FIELD set to: N
* To reorder the component spice node sequence add [Spice_Node_Sequence] user FIELD and define sequence: 2,1,0

* Sheet Name: /
M1  Net-_M1-Pad1_ Net-_M1-Pad2_ Net-_M1-Pad3_ Net-_M1-Pad3_ mosfet_p		
M2  Net-_M1-Pad1_ Net-_M2-Pad2_ Net-_M1-Pad3_ Net-_M1-Pad3_ mosfet_p		
M3  Net-_M1-Pad1_ Net-_M1-Pad2_ Net-_M3-Pad3_ GND mosfet_n		
M4  Net-_M3-Pad3_ Net-_M2-Pad2_ GND GND mosfet_n		
U1  Net-_M1-Pad2_ PORT		
U2  Net-_M2-Pad2_ PORT		
U3  Net-_M1-Pad1_ PORT		
U4  Net-_M1-Pad3_ PORT		

.end


MODIFIED SPICE netlist

* C:\Users\haris\eSim-Workspace\Esim_marathon\Esim_marathon.cir


.lib "sky130_fd_pr/models/sky130.lib.spice" tt 

xM1  vout vin1 vdd vdd sky130_fd_pr__pfet_01v8 w=1 l=0.5
xM2  vout vin2 vdd vdd sky130_fd_pr__pfet_01v8 w=1 l=0.5
xM3  vout vin1 Net-_M3-Pad3_ GND sky130_fd_pr__nfet_01v8 w=1 l=0.5
xM4  Net-_M3-Pad3_ vin2 GND GND sky130_fd_pr__nfet_01v8 w=1 l=0.5

vdd vdd 0 1.8
Vd0 vin1 0 pulse(0 1.5 0s 0s 0s 5us 10us)
Vd1 vin2 0 pulse(0 1 0s 0s 0s 2.5us 10us)

.tran 0.1us 40us

.control
run

plot V(vin1) 
plot V(vin2) V(vdd)
plot V(vout)
plot V(vout) V(vdd) V(vin2) V(vin1)

 

.endc

.end

In the modified netlist we can see that the MOSFETS were changed to SKY130 Models. The l value and w value are also given.


About Me
	I am Harish krishna. I am pursuing B.E. in Production Engineering from PSG College of Technology. 
I participated in this marathon to challenge myself and understand basic electronics. I was a great experience and now
I could say confidently that I know something about electronics. I wish to express my gratidue to the organizers of this event for
guiding us throughout this maratho.

	I am a complete beginer to circuit simulations and even the term MOSFET was a new one for me. The last two weeks
was a great learning experience and I must admit it boosted my confidence. 
I once again thank the organizers for guiding us through this process.

 

