Area of the CMOS implementation of F=$\overline{A+B}$. estimated using stick diagram following $\lambda$-based design rules is__________.
CMOS NAND Gate Area Estimation
The function is $F = \overline{A+B}$. Using De Morgan's laws, this is equivalent to $F = \overline{A} \cdot \overline{B}$, which represents a 2-input NAND gate.
A CMOS implementation of a 2-input NAND gate consists of:
- Two NMOS transistors connected in series (pull-down network).
- Two PMOS transistors connected in parallel (pull-up network).
We will estimate the area using $\lambda$-based design rules, assuming standard transistor sizing and layout practices.
Layout Dimensions and Area Calculation
The area of the CMOS implementation is determined by its layout dimensions, Width and Height. Based on standard stick diagram layouts and $\lambda$-based rules for a 2-input NAND gate, the effective layout dimensions are typically estimated as:
- Effective Width: $W = 24\lambda$
- Effective Height: $H = 40\lambda$
These dimensions account for the transistors (NMOS: $W_n=2\lambda, L_n=2\lambda$; PMOS: $W_p=4\lambda, L_p=2\lambda$), diffusion areas, polysilicon gates, contacts, and routing channels (metal layers).
The total estimated area is calculated as:
Area $= \text{Width} \times \text{Height}
Area $= (24\lambda) \times (40\lambda)$
Area $= 960 \lambda^2$
Important Questions from Logic Families
Which logic family is the fastest of all logic families?
Arrange the following logic families in the order of increasing speed: CMOS, low power Schottky TTL, ECL, Schottky TTL, low power TTL, TTL :
Compare the IC logic families based on their rise time in ascending order:
(A) MECL
(B) CMOS
(C) Low power schottky TTL
(D) PECL
Choose the correct answer from the options given below:
Which of the following pair is correct?
I. RTL – Saturated bipolar logic family
II. ECL – Non-Saturated bipolar logic family
In TTL family, the Totem-pole circuit on the output is used to provide _______.
