A Complex Band-Pass Filter for Low-Power and High-Performance Transceivers

In this paper a low-power and high-performance 2 ^nd -order complex band-pass filter in trans-impedance amplifier (TIA) configuration is presented. Thanks to the adopted topology for the passive network and active-components exceeds current solutions exhibiting a gain as high as 121.5 dB $_\Omega $ and 1.57 MHz of bandwidth centered around 1.33 MHz. The output noise is only 630 nV/ ${\sqrt {Hz}}$ . Furthermore, a new fully-differential class-AB operational trans-conductance amplifier (OTA) provides the required current to drive heavy ADC loads with very fast signals while an improved common-mode feedback circuit enables ultra low current without introducing stability and avoids start-up problems. The filter has been integrated in a 90-nm complementary metal oxide semiconductor (CMOS) technology. Despite the high performance and accuracy of the transfer function the power consumption is only $400~\mu \text{A}$ from a 1.2-V power supply.