Specialist foundry X-Fab has added a process module to its wide voltage- and temperature-range 180nm mixed-signal process that supports a set of transistors that exhibit lower 1/f flicker noise than the standard versions.
Three transistor types have been added to the PDK for the XH018 process: one is a 1.8V low-noise NMOS; the other two are complementary 3.3V versions. These transistors are primarily designed for sensor designs that need lower noise in the front-end amplifiers in order to achieve a high signal-to-noise ratio (SNR) with low-level signals. Among the key target applications are analog and digital microphone amplifiers, as well as implantable medical devices.
The 1.8V low-noise NMOS transistor improves flicker noise by a factor of eight compared to the standard XH018 device. The 3.3V NMOS transistor offers a tenfold reduction over its standard counterpart in the process’ transistor library. The 3.3V PMOS halves the noise for all drain currents.
The transistors are supported by a new release of models in the BSIM4 format that are more accurate than predecessors.
Luigi Di Capua, director marketing at X-Fab said the low-noise transistors only require one extra mask layer.