design of a 2 input multiplexer using dual rail domino logic

1. Design of a 2-input
multiplexer using Dual-Rail
Domino Logic
By: JULIE AILENEASUNCION

2. OVERVIEW
Dual Rail Domino is also known as
“Differential Cascade Voltage Switch”
(DCVS). A footless Domino circuit design, a
Data Driven technique where pre-charge
signal is substituted by input signal.
Domino logic cascade structure of several stages, the
evaluation of each of stage ripples the next stage
evaluation, similar to dominoes one after the other.
Dual-rail domino circuits accept both true and
complementary versions of the inputs and produce
true and complementary outputs.
Dual-rail domino gate design requires building
pulldown stacks implementing both true and
complementary versions of the function. For some
functions, these stacks are completely independent.

3. Advantages
1. Domino only performs non-inverting functions like
AND, OR but not NAND, NOR, or XOR. Dual-rail
domino solves this problem by taking true and
complementary inputs and producing true and
complementary outputs.
2. The monotonicity rule says that dynamic gates
should have monotonically rising inputs during
evaluation; that is, the inputs should start low and
stay low, start high stay high, or start low and rise,
but never start high and fall because the dynamic
gate will never be able to recover from a false
evaluation. The domino gate, consisting of the
dynamic/static pair, therefore always performs two
inversions and thus can only implement
noninverting functions. Such functions are called
monotonic; they include AND and OR, but not XOR.
Disadvantages
1. The existence foot transistor slows the
gate somewhat, as it presents an extra
series resistance.
2. Domino gates suffer from higher noise
sensitivity than their static CMOS
counterparts. This is because of their
low-switching threshold voltage,
which is equal to the VTH of the pull-
down NMOS devices.
Sizing
*sizes were chosen to make sure PUN and PDN reach its rail level.
Width Length
PMOS 10u 0.35u
NMOS 100u 0.35u

4. Dual Rail Domino Schematic using Electric software

5. Schematic using Electric software

6. Simulation Results