Dataset Updated on 06th October 2024
Transient Characteristics of CMOS inverter using ASPAP7nm
CMOS Inverter VTC Characteristics
Rise and fall time are calculated from the transient characteristics graph at 10% and 90% of the max values
Then time delay = (rise time + fall time)/2
Drain current is output at Vm by KCL whole of the current at output during operation is drain current .
Cg= cgsoxL + cgsoxL = 1.6e-10 x 7e-9 +1.6e-10x7e-9 = 22.40 e-19 F under no bias
Under bias Cg = Ig x t / VGS , here VGS = V1 and Ig= I1 The area under current curve gives charge stored within that time period.
Switching frequency f = 1/T where T is time of one cycle i.e time period between one fall and one rise
When pMOS is ON, nMOS is OFF
When pMOS pulls Vout to VDD VOH = VDD = 0.7 mV
Minimum output voltage occurs when input is high (Vin = VDD)
When pMOS is OFF, nMOS is ON The nMOS pulls Vout to Ground
VOL = 0 V
Input Low Voltage,
VIL – Vin such that Vin < VIL = logic 0
Find on VTC curve the point on the plot where ∂Vin/∂Vout =-1
Input High Voltage, VIH
– Vin such that Vin > VIH = logic 1
Find point ‘b’ on the plot where slope =-1
VNMH = VOH - VIH = VDD - VIH VNML = VIL
Av = Change in Vout /change in Vin
Output resistance can be calculated by ohm’s law Von/I2
Transconductance gm = Av/Rout
P = PS + Pdyn
– PS: static due to leakage
– Pdyn: dynamic (signal changing) term
Total P = IDDVDD + Cout VDD^2f
Co= Td /Ro
Leakage current can be calculated from the value of current at 0V input, mark that point on the graph.
A bootstrapped circuit is utilized for sample and hold.
