T. Chiba

Fujitsu Ltd., Kawasaki Si, Kanagawa, Japan

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Publications (6)6.13 Total impact

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    ABSTRACT: We describe a 16-channel 2.5Gb/s high-speed transceiver that operates off a single supply voltage ranging from 0.8V to 1.3V. We fabricated the transceiver in a 90nm standard CMOS, using CMOS full-swing circuits except for a limited number of speed- and timing-critical circuits that were implemented in reduced-swing circuit topologies. The reduced-swing circuits were the last-stage 2:1 selector of the multiplexer, transmitter output stage, the decision latches, phase interpolators and delay cells in the VCOs. At a supply voltage of 0.8V, the power consumption of 16-channel transceiver is 362mW, i.e., 23mW per transceiver channel.
    Custom Integrated Circuits Conference, 2005. Proceedings of the IEEE 2005; 10/2005
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    ABSTRACT: A 5-6.4 Gb/s transceiver, consisting of a parallel 12-channel transmitter (Tx), 12-channel receiver (Rx), clock generators based on LC-VCO phase-locked loops (PLLs), and a clock recovery unit, was developed. The Tx has a five-tap pre-emphasis filter, and the Rx has an equalizer with an intersymbol interference (ISI) monitor. Monitoring the ISI enables fine adjustment of loss compensation. The pre-emphasis filter in the Tx and the equalizer in the Rx compensate for transmission losses of up to 20 dB at 6.4 Gb/s, respectively. Both the Tx and Rx channels, including the PLLs, are 3.92 mm<sup>2</sup> in area. The transmitter dissipates 150 mW/channel at 6.4 Gb/s when compensating for a loss of 20 dB, and the receiver 90 mW/channel when compensating for the same loss.
    IEEE Journal of Solid-State Circuits 05/2005; · 3.06 Impact Factor
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    ABSTRACT: A 5 Gbps to 6.4 Gbps transceiver consists of a parallel 12-channel transmitter (Tx), 12-channel receiver (Rx), clock generators based on LC-VCO PLLs, and a clock recovery unit. The Tx has a 5-tap pre-emphasis filter, and the Rx has an equalizer with intersymbol interference (ISI) monitor. Monitoring the ISI enables a fine adjustment of the loss compensation. The pre-emphasis filter in the Tx and the equalizer in the Rx can compensate for a transmission loss of up to 20 dB and 15 dB at 6.4 Gbps, respectively. The areas of the Tx and Rx channels including the PLLs are both 3.92 mm<sup>2</sup>. The transmitter dissipates 150 mW/channel at 6.4 Gbps when compensating for a loss of 20 dB, the receiver 90 mW/channel when compensating for 15 dB loss.
    VLSI Circuits, 2004. Digest of Technical Papers. 2004 Symposium on; 07/2004
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    ABSTRACT: We describe a CMOS multichannel transceiver that transmits and receives 10 Gb/s per channel over balanced copper media. The transceiver consists of two identical 10-Gb/s modules. Each module operates off a single 1.2-V supply and has a single 5-GHz phase-locked loop to supply a reference clock to two transmitter (Tx) channels and two receiver (Rx) channels. To track the input-signal phase, the Rx channel has a clock recovery unit (CRU), which uses a phase-interpolator-based timing generator and digital loop filter. The CRU can adjust the recovered clock phase with a resolution of 1.56 ps. Two sets of two-channel transceiver units were fabricated in 0.11-μm CMOS on a single test chip. The transceiver unit size was 1.6 mm × 2.6 mm. The Rx sensitivity was 120-mVp-p differential with a 70-ps phase margin for a common-mode voltage ranging from 0.6 to 1.0 V. The evaluated jitter tolerance curve met the OC-192 specification.
    IEEE Journal of Solid-State Circuits 01/2004; · 3.06 Impact Factor
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    ABSTRACT: A quad 10Gb/s transceiver in 0.11μm CMOS communicates electric signals over balanced copper media. The transceiver uses a single 1.2V power supply and dissipates 415mW per channel. One PLL supplies a reference clock to two transmitter channels and two receiver channels. The transceiver contains analog front ends, clock recovery units, and 312MHz parallel interfaces.
    Solid-State Circuits Conference, 2003. Digest of Technical Papers. ISSCC. 2003 IEEE International; 02/2003
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    ABSTRACT: A 6 ns-latency 12 mW 5 Gb/s bidirectional link for short-haul (<5 m) balanced lines uses an on-chip switched-capacitor hybrid with echo-canceling capability. The clock-recovery circuit, based on a phase interpolator, makes the link tolerant to a 100 ppm difference between the frequencies of the transmit and receive clocks
    Solid-State Circuits Conference, 2001. Digest of Technical Papers. ISSCC. 2001 IEEE International; 02/2001