A 20 GS/s 5-Bit SiGe BiCMOS Dual-Nyquist Flash ADC With Sampling Capability up to 35 GS/s Featuring Offset Corrected Exclusive-Or Comparators

• Published in: IEEE journal of solid-state circuits 2009-09, Vol.44 (9), p.2295-2311
• Main Authors: Kertis, R.A., Humble, J.S., Daun-Lindberg, M.A., Philpott, R.A., Fritz, K.E., Schwab, D.J., Prairie, J.F., Gilbert, B.K., Daniel, E.S.
• Format: Article
• Language: English
• Subjects: Analog integrated circuits; Analog-digital conversion; Analog-to-digital converter (ADC); BiCMOS integrated circuits; BVceo; BVcer; Circuit testing; Circuits; Clocks; Comparators; Data capture; Devices; differential nonlinearity (DNL); Digital integrated circuits; digital signal processor (DSP); effective number of bits (ENOB); effective resolution bandwidth (ERBW); exclusive-or; fast Fourier transform (FFT); Flash; Germanium silicon alloys; Gray code; integral nonlinearity (INL); Integrated circuit technology; least significant bit (LSB); Power consumption; Probes; Sampling; Sampling methods; SiGe; Silicon germanides; Silicon germanium; spurious-free dynamic range (SFDR)
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2009.2022672

The design and wafer probe test results of a 5-bit SiGe flash ADC are presented. The integrated circuit, fabricated in a 200/250 GHz f T /F max , SiGe BiCMOS technology, provides a 5-bit analog to digital conversion with dual Nyquist operation at sample frequencies up to 20 GHz. Sampling clock rates are demonstrated as high as 35 GS/s. The ADC makes use of a comparator with an integrated exclusive-or function to reduce power consumption. The device also generates two half-rate interleaved outputs to ease data capture with laboratory equipment. An effective number of bits (ENOB) of nearly 5.0 is achieved for low-frequency input tones, dropping to 4.0 at 10 GHz.