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Abstract-The design and realization of an ultra-low noise operational amplifier is presented. Its applications are integrated low-frequency noise measurements in electronic devices and onchip phase-noise measurement circuit. This paper discusses the SiGe:C BiCMOS 0.25 µm design improvements used for low noise applications. The proposed three-stage operational amplifier uses parallel bipolar transistor connection as input differential pair for low noise behavior. This operational amplifier provides both low noise and high gain performances. This operational amplifier has an area of only 660×250 µm 2 with an equivalent input noise floor of only 1.1 nV/ √ Hz square root at 10 kHz. The measured noise characteristics (versus total power consumption) are better than those of most operational amplifiers commonly adopted in low-frequency noise measurements. The AC gain is 83 dB and the unity gain bandwidth is 210 MHz, with a total current consumption of 18 mA at 2.5 V supply voltage.

To cite this version:Teddy Borr, Julien Juyon, Éric Tournier. A both Gaussian and sinusoidal phase-to-amplitude converter for low-power ultra-high-speed direct digital synthesizers. NEWCAS, Jun 2011, Bordeaux, Abstract-This paper introduces a new bipolar differential pair topology for both gaussian and sinusoidal signal shaping, to be used as a phase-to-amplitude converter alternative in lowpower ultra-high-speed DDS. A DDS using this converter, with a 9-bit frequency resolution and an 8-bit amplitude resolution has been designed in a 0.13 µm SiGe BiCMOS technology, with f t /f max of 200/250 GHz, and simulated up to a 20 GHz operating clock frequency. It consumes 585 mW under a 2.8 V power supply. Simulated triangle shape allows an optimal SFDR of −44.5 dBc in sinus mode and a SLRR of −43.5 dBc in gaussian mode.