Chapter 6: Difference between revisions

Latest revision as of 23:00, 24 March 2010

Boolean Algebra
A	B	NAND $\overline{A B}$	NOR $\overline{A + B}$	XOR $A \oplus B$
0	0	1	1	0
0	1	1	0	1
1	0	1	0	1
1	1	0	0	0

"If the variables in a logic expression are replaced by their inverses, and if the AND operation is replaced by OR, the OR operation is replaced by AND, and the expression is inverted, the resulting logic expression yields the same values as before the changes."<ref>Electronics p.353</ref>
It is possible to create any combinatorial logic function with solely NAND (or NOR) gates

Gate	Symbol	NAND equivalent
Inverter	$\overline{A}$	$\overline{A A}$
AND	$A B$	$\overline{(\overline{A} + \overline{B})}$
OR	$A + B$	$\overline{(\overline{A} \overline{B})}$

Zero static power consumption
$K P_{p} = \frac{1}{2} K P_{n}$ , thus ${\frac{W}{L}}_{p} = 2 {\frac{W}{L}}_{n}$ to maintain symmetric transfer characteristics.

p.365: Why even have R_on?
p.377: What problems are there with the NMOS pull-up?
p.382: For CMOS, are the transistors in Triode or Saturation when they're in the "ON" state? How can we tell?

@@ Line 25: / Line 25: @@
 |OR||<math>A+B</math>||<math>\overline{(\overline{A} \, \overline{B})}</math>
 |}
+===CMOS Inverter===
+*Zero static power consumption
+*<math>KP_p=\frac{1}{2}KP_n</math>, thus <math>\frac{W}{L}_p=2\frac{W}{L}_n</math> to maintain symmetric transfer characteristics.
+===Questions===
+*p.365: Why even have R_on?
+*p.377: What problems are there with the NMOS pull-up?
+*p.382: For CMOS, are the transistors in Triode or Saturation when they're in the "ON" state? How can we tell?
 ===References===
 <references/>