# -*- coding: utf-8 -*-
"""
Created on Fri Feb 06 22:27:47 2015

@author: mespence
"""

from numpy import logspace, array, tile, pi
from pylab import semilogx, loglog, xlabel, ylabel, title, legend, figure, axis

Cg    = 1e-15  # F/um
Cd    = 1e-15  # F/um
Vth   = 0.4    # V
Vdd   = 1.0    # V
Jcrit = 1e-4   # A/um
Vgs   = 0.8    # V
R0n   = 1e3    # Ohm*um

# Amplifier
BW = logspace(6,12)
Av = array([[2],[3],[5],[10]])
Cl = 2e-14
W0 = 1               # in um

# We need to find the real W iteratively
def W(W0):
    C = Cl + Cd*W0
    R = 1/BW/C
    gm = Av/R
    Id = gm/2*(Vgs-Vth)
    W = Id/Jcrit
    return W
for x in range(3):
    W0 = W(W0)
figure()
semilogx(tile(BW,[len(Av),1]).T/2/pi, 1e6*(W0*Jcrit*Vdd).T)
axis([10**6, 10**10, 1, 100])
xlabel("Bandwidth [Hz]")
ylabel("Power [uW]")
legend(["Av=2","Av=3","Av=5","Av=10"],loc='lower right')
title("Bandwidth vs. Power in Common Source Amplifier")

figure()
loglog(1/tile(BW,[len(Av),1]).T, 1e6*(W0*Jcrit*Vdd).T)
#axis([10**6, 10**10, 1, 100])
xlabel("Time Constant [s]")
ylabel("Power [uW]")
legend(["Av=2","Av=3","Av=5","Av=10"],loc='upper right')
title("Time Constant vs. Power in Common Source Amplifier")

## Inverter
Winv   = logspace(-1.5,2.5,100)                     # in um
Clinv  = array([[12],[40],[200]])*1e-15
Ctot = tile(3*Cd*Winv,[len(Clinv),1]) + tile(Clinv,len(Winv))
Ron = R0n/Winv
td  = 1e12*Ron*Ctot
E   = 1e6*(Ctot+3*Winv*Cg)*Vdd**2
figure()
loglog(td.T,E.T)
ylabel("Energy/transition [uJ]")      
xlabel("Delay [ps]")
legend(["Cl=12 fF","Cl=40 fF","Cl=200 fF"])
title("Energy vs. Delay in Inverter")