III. Gm-C Filtering - Epublications - Université de Limoges

depicts this Rds resistance versus the drain current. As it may be found in the literature, the
smaller the gate length L, the smaller the drain-source resistance since:
LU a
R ds = , (III.71)
I d
where Ua is a factor depending on channel-length modulation.
Figure 96. Drain-source resistance versus drain current
As far as intrinsic noise and linearity of CMOS technologies are concerned, it is very
difficult to compare one to another. Indeed, it strongly depends on the modeling and its
accuracy. Comparing technologies from different founders may lead to misinterpretations.
An important point in comparing technologies is their ability to support high supply
voltages by means of thick oxide transistors. Since the RF filter should be able to handle the
LNA output swing, a high enough supply voltage is required. Indeed a 1.2V supply in 65nm
CMOS would not be sufficient to handle a large swing without distortions. Minimum gate
lengths and supply voltages of the various studied technologies are summarized in Table 6.
CMOS technology
Table 6. CMOS technologies comparison
Name C14 C13 C90 C65 C45
Provider NXP Jazz TSMC TSMC TSMC
oxide type thin thick thin thick thin thick thin thick thin thick
Lmin (µm) 0,16 0,322 0,12 0,36 0.1 0.28 0,06 0,28 0,04 0,27
Supply (V) 1,8 3,6 1,2 3,3 1.2 2.5 1,2 2,5 1.1 2,5
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