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

IV.3.e Filter Chip
Figure 167 depicts the die microphotograph of the final chip. The different blocks can
be recognized quite easily.
Figure 167. Rauch filter chip photograph
IV.3.f Post-layout Robustness Simulations
Following performances are the results of simulations after extraction of the parasitic
due to the layout of the filter.
IV.3.f.i Final Extraction Performances
Figure 168, Figure 169 and Figure 170 describe the PVT variations of the filter Qfactor,
gain and noise figure. From these graphs, one can notice the strong influence of the
temperature since, as an example, Q varies (at 100MHz) from 2.5 for 120°C to 3.5 for -20°C.
This is a consequence of designing an RC based structure. Indeed, resistors show strong
temperature variations.
As far as the supply voltage dependency is concerned, a 10% variation of the nominal
value show limited effects on these parameters, demonstrating the robustness of the design.
Figure 168. PVT variations of the filter Q-factor
- 148 -