Wai Lee

A 6.25-Gb/s binary transceiver in 0.13-/spl mu/m CMOS for serial data transmission across high loss legacy backplane channels

A transceiver capable of 6.25-Gb/s data transmission across legacy communications equipment backplanes is described. To achieve a bit error rate (BER) <10/sup -15/, transmit and receive equalization that can compensate up to 20 dB of channel loss is employed to remove intersymbol interference (ISI) resulting from finite channel bandwidth and reflections. The transmit feed-forward equalizer (FFE) uses a four-tap symbol-spaced programmable finite impulse response (FIR) filter followed by a 4-bit digital-to-analog converter (DAC) that drives a 50-/spl Omega/ transmission line. The receiver uses a half-baud-rate adaptive decision feedback equalizer (DFE) that cancels the first four symbol-spaced taps of postcursor ISI without use of speculative techniques. Both the transmitter and receiver use an LC-oscillator-based phase-locked loop (PLL) to provide low jitter clocks. Techniques to minimize the complexity of the FIR and DFE implementations are described. The transceiver is designed to be integrated in a standard ASIC flow in a 0.13-/spl mu/m digital CMOS technology. System measurements indicate the ability to transmit and recover data eyes that have been fully closed due to crosstalk and signal loss.

A 6.25Gb/s binary adaptive DFE with first post-cursor tap cancellation for serial backplane communications

A 6.25 Gb/s serial receiver with a 4-tap adaptive DFE is implemented in a 0.13 /spl mu/m 7LM CMOS process. Direct cancellation of the first post-cursor ISI is achieved, enabling recovery of a data eye fully closed from channel losses and crosstalk. A BER<10/sup -15/ is measured over legacy backplane channels.

A 1-V programmable DSP for wireless communications [CMOS]

In an effort to extend battery life, the manufacturers of portable consumer electronics are continually driving down the supply voltages of their systems. For example, next-generation cellular phones are expected to utilize a 1-V power supply for their digital component. To address this market, an energy-efficient, programmable digital signal processing (DSP) chip that operates from a 1-V supply has been designed, fabricated, and tested. The DSP features an instruction set and micro-architecture that are specifically targeted at wireless communication applications and that have been carefully optimized to minimize power consumption without sacrificing performance. The design utilizes a 0.35-/spl mu/m dual-V/sub t/ technology with 0.25-/spl mu/m minimum gate lengths that enables good performance at 1 V. Specifically, the chip dissipates 17 mW at 1 V, achieving 63-MHz operation with a power-performance metric of 0.21 mW/MHz.

A 1 V DSP for wireless communications

Modern cellular phones are placing increasingly stringent demands on battery life and, therefore, on the power dissipation of the embedded DSP circuitry. At the same time, greater computational throughput is being required of the DSP, for example to implement more sophisticated speech and channel coding algorithms. Earlier low-power DSPs were reported. However, further improvements in power and performance are required. This paper describes a full-function, 1.6M-transistor, fixed-point programmable DSP designed for wireless communication applications to address these dual constraints of lower power and higher throughput. This is achieved by operating at 1V and using a dual-V process to maintain high performance.

A 6.25GHz 1V LC-PLL in 0.13/spl mu/m CMOS

A 6.25GHz PLL with integrated LC-tank VCO, on-chip loop filter and quadrature outputs is fabricated in 0.13mum CMOS technology. Operated at 1V supply with 62.5MHz input reference clock frequency, an output clock jitter of 0.5psrms is achieved by using a charge pump with rail-to-rail operation and leakage-current cancellation

Programmable termination for CML I/O's in high speed CMOS transceivers

This paper describes I/O circuits that can be used in high-speed transceivers to communicate with next generation and legacy devices. We describe the transmitter and receiver front-end circuits that are designed to operate with dual termination voltage supplies. The receiver characterization, ESD protection and system level power up issues related to gate-oxide and electro-migration reliability are discussed.