(Solved):
d) Determine the capacitance per transistor gate for a 16K Static RAM by 1-bit memory array. The ...
d) Determine the capacitance per transistor gate for a 16K Static RAM by 1-bit memory array. The array is organized in a square array of 128 by 128 Static RAM memory cells. Assume the select line is driven by an ideal voltage step from cell number 1 . Use the parameters in Table 1. Table 1
To determine the capacitance per transistor gate for a 16K Static RAM by 1-bit memory array, we need to consider the capacitance of the select transistor gate.
First, let's calculate the total number of memory cells in the array:
Number of memory cells = 128 x 128 = 16,384
Next, we can calculate the width of the polysilicon select line:
Width of polysilicon select line = 3?m
The length of the polysilicon select line is equal to the square root of the physical array area:
Length of polysilicon select line =
Therefore, the total resistance of the polysilicon select line is:
Resistance of polysilicon select line =
The delay of the select line to reach cell number 128 is given as:
Selectline delay to cell no. 128 = 63.03ns
We can use this to calculate the capacitance of the select transistor gate:
Capacitance of select transistor gate =
=
Finally, we can calculate the capacitance per transistor gate by dividing the capacitance of the select transistor gate by the area of the transistor gate:
Capacitance per transistor gate = Capacitance of select transistor gate / Select transistor gates area
= 0.054fF/?m²