A low-noise current preamplifier in 120 nm CMOS technology

Abstract. In this paper we examine the impact of deep sub-micron CMOS technology on analog circuit design with a special focus on the noise performance and the ability to design low-noise preamplifiers. To point out, why CMOS technology can grow to a key technology in low-noise and high-speed applications, various amplifier stages, applied in literature, are compared. One, that fits as a current preamplifier for low-noise applications, is the current mirror. Starting from the basic current mirror, an enhanced current preamplifier is developed, that offers low-noise and high-speed operation. The suggested chip is realized in 0.12 μm CMOS technology and needs a chip area of 100 μm×280 μm. It consumes about 15 mW at a supply voltage of 1.5 V. The presented current preamplifier has a bandwidth of 750 MHz and a gain of 36 dB. The fields of application for current preamplifiers are, for instance, charge amplifiers, amplifiers for low-voltage differential signaling (LVDS) based point-to-point data links or preamplifiers for photodetectors.