Hirohito Higashi

5 Gb/s bidirectional balanced-line link compliant with plesiochronous clocking

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.

5-6.4 Gbps 12 channel transceiver with pre-emphasis and equalizer

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/. 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.

3.5 A 56Gb/s NRZ-electrical 247mW/lane serial-link transceiver in 28nm CMOS

With the rapid growth of data traffic in data centers, data rates over 50Gb/s/signal (e.g., OIF-CEI-56G-VSR) will eventually be required in wireline chip-to-module or chip-to-chip communications [1-3]. To achieve better power efficiency than that of existing 25Gb/s/signal designs, a high-speed yet energy-efficient front-end is needed in both the transmitter and receiver. A receiver front-end with baud-rate architecture [1] has been successfully operated at 56Gb/s, but additional components such as eye-monitoring comparators, phase detectors, and clock recovery circuitry as well as a power-efficient transmitter are needed to build a complete transceiver.

A 0.8-1.3V 16-channel 2.5Gb/s high-speed serial transceiver in a 90nm standard CMOS process

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.

A 28.3 Gb/s 7.3 pJ/bit 35 dB backplane transceiver with eye sampling phase adaptation in 28 nm CMOS

28.3 Gb/s transceiver with 35 dB channel loss equalization is presented. The transmitter deploys 3-tap feed forward equalizer (FFE). The driver employs the hybrid architecture of low voltage differential signaling (LVDS) and source-series-terminated (SST) driver which enables the low power consumption and output signal amplitude fine tune. The receiver comprised with continuous time linear equalizer (CTLE) and 2-tap loop unrolled decision feedback equalizer (DFE). It saves the power consumption by not applying DFE at the eye edge, and increases the eye margin with adaptive sampling clock phase adjustment capability. The transceiver is composed of one PLL and four lanes, occupies 1.67 mm2 and consumes 829 mW (7.3 pJ/bit).