Low-voltage differential signaling
Article Abstract:
The IEEE Computer Society P1596.3 is developing a high-speed signal interface as an alternative to the ECL-level signals specified by the IEEE Std 1596-1992 Scalable Coherent Interface (SCI). The goal for the interface is to have it perform at least as well as emitter-coupled logic (ECL) at a lower cost than complementary metal-oxide semiconductor (CMOS) implementations. Most current logic signals are single-ended and propagate on a single conductor to a receiver, but the signals co-exist with noise from many sources. Small voltage swings are desirable for really high speeds or really low power. Noise is eliminated by arranging the wiring so the reference voltage is exposed to the same noise as the signal. At high speeds, the receiver is designed to ignore any voltage that appears equally on the two conductors. To minimize noise, good system design requires that the net current rest at zero. Other interface concepts are discussed.
Publication Name: IEEE Spectrum
Subject: Engineering and manufacturing industries
ISSN: 0018-9235
Year: 1992
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Mixing 3-V and 5-V ICs: until a full complement of 3-V ICs is available, many systems will have to operate with at least two power supplies
Article Abstract:
While many integrated circuits (IC) now run from 3-V power supplies, only 5-V versions are available for some peripheral components. The solution is a mixed-voltage IC system, although designing such chips are problematic, since voltages must interface in bidirectional translation on the same system bus. Mixed-voltage systems should be considered a necessary evil that exist only because of an incomplete selection of low-voltage systems. Still, mixed-voltage systems can extend battery life and retain more heat than 5-V systems, which can offset mixed systems' higher cost and hardware requirements. A key goal of mixed-voltage system design is to minimize the number of required voltages and the number of devices used to create them.
Publication Name: IEEE Spectrum
Subject: Engineering and manufacturing industries
ISSN: 0018-9235
Year: 1993
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Gunning transceiver logic
Article Abstract:
Integrated circuit (IC) interfaces need to change radically if systems are to fully utilize the computing power of present-day very large-scale integration. The nearly rail-to-rail swings of 5-V TTL create too much noise and drags out settling times too long. Gunning transceiver logic (GTL) implemented in complementary metal-oxide semiconductor (CMOS) easily meets the need for the speed and performance of emitter-coupled logic or bipolar CMOS at the power and cost of TTL-compatible TTL. GTL output voltage levels are nearly the same for unterminated and terminated applications, and it does not require two wires for each connection, so it does not increase the pin requirements for each device.
Publication Name: IEEE Spectrum
Subject: Engineering and manufacturing industries
ISSN: 0018-9235
Year: 1992
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- Abstracts: Coping with the dual-use dilemma. ICs going on a 3-V diet: after over a decade at 5 V, higher IC densities require a 'cooler' 3-V standard, with transitional systems likely to mix 3 and 5 V
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