On-Chip Communication Architectures

413

drive of the gates I

out

will increase which is offset, however, by an increase in the

output capacitive load C

L

. The I

out

/ C

L

ratio remains essentially constant [6]. A care-

ful balance of the current drive and output load is therefore necessary to enhance

circuit performance.

Aside from improving circuit performance by increasing the current drive, tran-

sistor sizing also affects the power characteristics of a circuit. A simple approxi-

mation treats the circuit power as linearly proportional to the total active area

A of a driver, that is, P  CV

2

f, where C  C

ox

A, and the gate oxide capacitance

per unit area C

ox

is ...