Transistors target noise-sensitive applications

These transistors are mainly designed for sensor deployments which require low-noise signal amplification to achieve high signal-to-noise ratio (SNR). Among the key target applications are analogue and digital microphone amplifiers, which are widely used in mobile phones and headsets, as well as implantable medical devices, such as pacemakers.

The new 1.8V low-noise NMOS transistor introduced by X-FAB delivers an improvement factor of eight times lower flicker noise compared to the standard XH018 device. The new 3.3V low-noise NMOS transistor gives up to ten times lower flicker noise, while the flicker noise for the 3.3V low-noise PMOS transistor that complements it is halved for all drain currents.

Flicker noise, also known as 1/f noise, is the dominant noise at low frequencies, between 1Hz to 1MHz. For applications working in this spectrum, it is important that the flicker noise is kept to a minimal level.

Using the new complementary low-noise 3.3V transistors makes it easier for designers to realise noise-critical designs, enabling them to achieve a high SNR - as required, for example, by digital amplifier ICs. Designers can also benefit from more accurate models which are supplied in the new BSIM4 format. With this, the chances for achieving first-time-right implementation of complex analogue circuits are significantly improved.

Luigi Di Capua, Director Marketing at X-FAB, commented: “X-FAB has been setting the benchmark for low-noise performance in its 350nm technology for many years. We are proud to now also offer industry-leading low-noise devices via our 180nm XH018 platform. By adding just one extra mask layer, all three ultra-low-noise transistors can be incorporated into noise-sensitive circuit designs.”