A 500 mW ADC-Based CMOS AFE With Digital Calibration for 10 Gb/s Serial Links Over KR-Backplane and Multimode Fiber.

Autor: Jun Cao, Bo Zhang, Ullas Singh, Delong Cui, Vasani, Anand, Garg, Adesh, Wei Zhang, Kocaman, Namik, Deyi Pi, Raghavan, Bharath, Hui Pan, Fujimori, Ichiro, Momtaz, Afshin
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Zdroj: IEEE Journal of Solid-State Circuits; Jun2010, Vol. 45 Issue 6, p1172-1185, 14p
Abstrakt: This paper presents the design of an analog-front-end (AFE) integrated into a DSP-based transceiver for both serial 10 Gbps KR-backplane and long-reach-multimode-fiber (LRM) applications. The receiver consists of a programmable gain amplifier (PGA) and a 6-bit 4-way time-interleaved ADC, which is digitally calibrated to compensate for the offset, gain and phase mismatches between the interleaved channels. With a 5 GHz input signal, the ADC achieves overall SNDR of 29 dB, while the measured SNDR of flash sub-ADC is 31.6 dB. The power efficiency FoM of the complete interleaved ADC is 1.4 pJ per conversion step. The PLL uses a calibrated LC-VCO and the TX features a full-rate 3-tap de-emphasis at the output. Inductively tuned buffers connected in tandem are employed to distribute the 10 GHz clock. Random and deterministic jitter measured at the TX output are 0.38 psrms and 2.65 pdpp, respectively. Implemented in 65 nm CMOS technology, the AFE occupies an area of 3 mm² and consumes 500 mW from a 1 V supply. BER of less than 10-15is measured over legacy backplanes with 26 dB loss at Nyquist and the measured transceiver optical sensitivity is less than -13 dBm for all four LRM stressors, exceeding both the KR and the LRM specifications. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index