OREANDA-NEWS. September 20, 2012. Fujitsu Laboratories Limited today announced that it has developed a CMOS power detector with built-in temperature compensation, featuring a compact design and low power consumption suitable for use in smartphones and other mobile terminals.

Reducing the mounted area required for components and circuits in mobile terminals is an important factor in reducing their size and cost, but they occupy a relatively large mounted area, because the power detectors used in the transmitters for wireless communications terminals are typically comprised of several radio-frequency (RF) amplifiers. Diodes are known to be an alternative for making power detectors smaller, but their characteristics change with temperature, and the temperature compensation they require has been problematic.

Fujitsu Laboratories has developed a diode-based power detector with a technology that simultaneously enables temperature compensation, resulting in a power detector with a mounted area of only 0.04 mm2 and power consumption of 0.3 mW. Compared to conventional detectors, this requires less than 1/25th the mounted area and consumes 1/10th the power, contributing to smaller, less expensive mobile terminals.

Details of this technology are being presented at ESSCIRC 2012, the European Solid-State Circuits Conference 2012, which opened on September 17th in France.
Background

In recent years, the popularity of mobile terminals such as smartphones and tablets has soared. These mobile terminals are comprised of a large number of internal components; therefore, reducing the mounted area required for these components and circuits is an important factor in reducing overall size and cost.