The ACS8942A is a jitter attenuating and multiplying phase-locked loop for generating ultra-low-jitter output clocks for Sonet and SDH network equipment.
Sampling now from Semtech, the ACS8942A is a jitter attenuating and multiplying (JAM) phase-locked loop (PLL) for generating ultra-low-jitter output clocks for Sonet and SDH network equipment. The ACS8942A is the latest addition to Semtech’s synchronous equipment timing source (SETS) product family. The IC features jitter generation as low as 0.10ps RMS (G.813, STM-16, 1 to 20MHz band) and 0.93ps RMS (GR-253, OC-48, 12kHz to 20MHz band), well below the jitter requirements of ITU-T and Telcordia specifications for up to OC-48/STM-16 systems.

The device dejitters the output of a line card protection device or line card clock synthesiser, providing a clock-cleaning solution for DSL access multiplexers and metropolitan or edge networking equipment with very tight jitter budgets.

With a tiny 5 x 5mm QFN 32-pin package, the device can be used to attenuate jitter in the network element at the point of use.

The ACS8942A features a unique integrated voltage controlled oscillator, which saves cost and board space; it also eliminates long-term centre frequency drift and the potential for mechanical failure of an external oscillator.

‘The ACS8942A offers a significant advantage to the designer who is finding that jitter is impacting a high-speed design’, stated Stewart Kelly, Director of the Advanced Communications Products Division at Semtech.

‘With this device in our successful SETS product portfolio, Semtech has become the first one-stop shop to fulfill all Sonet/SDH network element, standards-compliant clocking requirements’.

The device nominally inputs a 155.52MHz reference clock via a single, differential LVPECL input and can be configured to provide either 622.08 or 77.76MHz on a single, differential CML output.

The IC features an external feedback-operating mode that allows it to input other common Sonet/SDH spot frequencies (19.44, 38.88, 77.76MHz), and allows the final output signal from any external buffers and dividers to be in exact phase alignment with the clock input.

Engineering samples of the ACS8942A are available now from Semtech’s authorised network of sales representatives and distributors.

A new device from Texas Instruments is billed as the world’s first multiple-function, single-supply, logic level translator.
A new device from Texas Instruments is billed as the world’s first multiple-function, single-supply, logic level translator. Providing designers with PCB space savings and reduced bill of material part count, the SN74AUP1T97/98 combines common Boolean logic functions and level translation into a single device. This device offers up to nine configurable gate logic functions, including four functional combinations not found in traditional logic gates.

Using TI’s Low power AUP (advanced ultralow power) logic technology, this level translator offers very low static and dynamic power consumption for battery-operated end equipment.

The SN74AUP1T97/98 has a single supply-voltage pin, which simplifies trace routing and provides reduced power consumption.

The device is optimised to accept 1.8V LVCMOS input signals, while operating from a single 3.3V supply (1.8 to 3.3V translation), and can also perform voltage translation from 1.8 to 2.5V, 2.5 to 3.3V and 3.3 to 2.5V.

The AUP1T97/98 employs Schmitt trigger inputs, which eliminate input noise, improve output signal integrity, and allow slow transition of the input signal.

The SN74AUP1T97 and SN74AUP1T98 are both offered in TI’s miniature (1.4 x 0.9mm) NanoStar and NanoFree, lead (Pb)-free, packages, as well as traditional SC-70 and SOT-23 packages.

The devices are available to sample now.

Budgetary pricing for both the SN74AUP1T97DCKR and the SN74AUP1T98DCKR is set at $0.24 in quantities of 1000.

Inphi Corp has significantly expanded its Asia-Pacific operation with the opening of a Korean office and the addition of distribution partners specifically for its precision timing components.
In response to growing demand for its leading-edge DDR2 precision timing components, Inphi Corp has significantly expanded its Asia-Pacific operation with the opening of a Korean office and the addition of distribution partners specifically for its precision timing components. Inphi’s new Korean office is in Seongnam-si, Gyunggi-do, Korea, close to the leading Korean memory developers who seek the high performance solutions delivered by Inphi through its ExacTik Family of precision timing devices. The office will be managed by il Hwan Lim, Director of Sales and Marketing, Korea, who joins Inphi after working for nearly 15 years in the memory market with Samsung.

Customer technical support for Korea will be provided by Douglas Millar, Application Engineering Manager, who joins Inphi Corporation with 30 years of experience at Intel and Nortel.

Millar has received numerous patents for his work and has been published in leading trade journals throughout his tenure in the industry.

Complementing the new team, Inphi announced it expanded its distribution coverage for Korea with the addition of Elim S and T, based in Seongnam-si, Gyunggi-do, to focus solely on Inphi’s ExacTik precision timing components.

The company is directed by CEO Paul Shin who worked for a number of years at Teradyne where he was responsible for memory test systems sales to market leaders such as Hynix and SEC.

Inphi’s entire line of high-speed precision electronic components now meets or exceeds the most comprehensive worldwide environmental safe-product rules.
Following the adoption of its green product strategy in early 2002, Inphi’s entire line of high-speed precision electronic components for optical communications, test and instrumentation, microwave and computing applications now meets or exceeds the most comprehensive worldwide environmental safe-product rules. Anticipating customer needs and working proactively to meet regulatory requirements, Inphi’s products are available in green packages, well ahead of European Union’s RoHS compliance deadlines. ‘We’ve established procedures so that every part is in alignment with the most stringent of the global standards and regulations’, said Paul Washkewicz, Inphi Corp’s Vice President, Marketing and Sales.

‘This is a significant industry change, affecting nearly 100% of the electronics used in the market’.

‘By aggressively pursuing a green product strategy, Inphi is easing this transition for its customers and for all manufacturers facing this design and engineering challenge’.

‘We will for the foreseeable future, continue to supply our existing products to those customers who still need the time to convert their manufacturing lines over those meeting RoHS standards’.

Across the globe, countries are addressing growing environmental concerns by adopting legislation to restrict or eliminate materials that can be harmful to the environment.

The RoHS regulations mandate that lead and other hazardous substances be banned in electrical and electronic equipment sold there beginning July 2006.

North America agreed in November on a roadmap to adopt lead-free soldering by the end of 2005.

The Japanese Ministry of International Trade and Industry has been phasing in programmes to recycle and label lead-bearing products since 2001.

New PC clock devices support Intel’s next-generation notebook and desktop PC platforms.
Building on its rapid growth in the PC clock market, IDT (Integrated Device Technology ) has released new PC clock devices that support Intel’s next-generation notebook and desktop PC platforms. For next generation Intel Centrino mobile technology based laptops, a new chipset (code-named ‘Calistoga’) will be released for which IDT has released a new series of single-chip, four-PLL (phase-locked loop) PC clock devices that enable the independent control of key clock circuits within the system, resulting in greater flexibility and increased system performance. The IDT clocking solutions for Intel’s next generation Intel 945 Express Chipset family for desktop PCs are also based on a four-PLL architecture.

Both the desktop and notebook PC clock devices offer dedicated PLLs for, CPU, PCI Express, SATA and USB clocks, which provide robust performance and reduces jitter for SRC clocks.

The devices also include built-in independent spread-spectrum control (SSC) to aid in the reduction of electromagnetic emissions (EMI).

The devices targeting the next generation of Intel Centrino mobile technology based notebooks include a power management control feature that enhances battery life.

The desktop device architecture incorporates programming that enables a linearly scalable frequency adjustment as opposed to the commonly used discrete stepping approach, providing enthusiasts the ability to fine-tune their system for better performance.

A new family of silicon oscillators aim to provide a simple, compact and robust timing solution for FPGAs, CPLDs, microprocessors and DSPs.
Linear Technology’s newest family of silicon oscillators, the LTC6905-xxx, generate a fixed frequency clock output from 20 to 133MHz. These oscillators provide a simple, compact and robust timing solution for FPGAs, CPLDs, microprocessors and DSPs. Eliminating the external trim components, these precision oscillators minimise board space and maximise accuracy.

It’s a familiar story: just as vacuum tubes, relays and core memory were transformed by solid state technology, silicon oscillators offer big advantages over traditional resonating elements.

Linear Technology’s silicon fabrication and assembly ensures that the LTC6905-xxx family is inherently immune to shock and vibration, a key advantage over crystals and ceramic resonators.

Typical canned oscillators are challenged by long startup, duty cycle drift and significant power usage.

The LTC6905-xxx improves on all of these features with a consistent startup (100us typical), low duty cycle variation (+/-2.5%) and half of the power consumption (12mA Max at 100MHz).

Furthermore, the LTC6905-xxx can operate over the full automotive temperature range (-40 to +125C).

The LTC6905-xxx series is offered in a small ThinSOT package.

These parts operate with a single 2.7V to 5.5V power supply and provide a rail-to-rail, CMOS output.

An output enable function is provided to disable the output and eliminate pulse slivers when re-enabled.

‘The combination of ruggedness, size, power, and performance addresses a demand in the oscillator market that was previously tough to meet’, according to Doug LaPorte, Design Section Lead for Linear Technology.

The LTC6905-xxx family is available with a master clock frequency of 133, 100, 90 or 80MHz.

An internal three-state divider (DIV input) allows for division of the master clock by 1, 2 or 4 providing a wide range of possible frequencies.

For nonstandard frequencies, the LTC6905-xxx can be factory trimmed to any output between 2.2 and 170MHz.

A resistor programmable version is also available for applications requiring factory or field adjustment to any frequency from 17 to 170MHz.

All versions are in full production, with pricing starting at $1.15 each in 1000-piece quantities.

Alliance Semiconductor has expanded its analogue and mixed signal product portfolio with its newest families of high-performance zero-delay buffers and non-zero-delay buffers.
Alliance Semiconductor Corp has expanded its analogue and mixed signal product portfolio with the availability of its newest families of high-performance zero-delay buffers (ZDBs) and non-zero-delay (NZDB) buffers. The ASM5000 family of PLL-based ZDBs and the ASM2000 family of non-PLL-based NZDBs are designed to address the precise, high accuracy and high-performance (greater than 250MHz) clocking needs of various datacommunications, networking, telecommunications, industrial and many consumer systems. Fast edge rates (less than 1ns), low propagation delays (50-500ps) high accuracy (duty cycle stability and jitter) along with very high frequency support (greater than 250MHz), characterise both families of these precision buffers.

The devices are designed to support one or two 50ohm transmission lines.

This expansion includes many of the standard high performance (250MHz+) buffers currently in volume demand.

Alliance Semiconductor expects to continue the product expansion as the line continues its evolution into high performance, very low voltage, high accuracy applications.

These precision non-PLL-based products support either 2.5 or 3.3V power supplies and provide support from DC to well in excess of specification of 250MHz, with up to 18 outputs for precise fanout and distribution of the clock signal with very low prop delay and output skews.

Many of these products (ZDBs and NZDBs) support a ’split-rail’ design that provides for either 3.3 or 2.5V LVCMOS outputs for conversion/translation of either a LVCMOS or LVPECL input to LVCMOS, and thus allows for use across multiple platforms.

Single and multiple output bank configurations are supported as well.

This high-performance family of low voltage zero-delay buffers provides support for frequencies from DC to beyond specification (greater than 250MHz compared with the 200MHz spec) with fanouts of 12 and 14, and very low propagation delays (Tpd and Tskew) for precise resynchronisation (zero delay) and accuracy.

These features coupled with fast edge rates and low jitter, enable designers to maximise their timing budgets with minimal error budget contribution.

Packaged in 32- and 52-pin LQFP and TQFP packages, Alliance offers both commercial and industrial temperature grades, with standard tin-lead/Pb-free RoHS and/or green compliant products.

According to Mark Sherwood, Director of Marketing for the Alliance Mixed Signal Business Unit: ‘This is a significant introduction and roll out for Alliance Semiconductor’.

‘The combination of these low voltage high performance ZDB’s and LVNZDBs will add significantly to the current offering from Alliance mixed signal and provides entry into the high-end LVCMOS clock market’.

‘This release allows Alliance Semiconductor to support all key aspects of the clock tree - ie clock synthesis, frequency generation, clock signal distribution and resynchronisation’.

‘With this new addition, Alliance Semiconductor’s Mixed Signal Group is now well positioned in clock and timing with a very wide, in-depth and comprehensive portfolio into the high accuracy and performance applications segments’.

Target applications include routers, switches, hubs, basestations and redundant array of independent disks (RAID) storage arrays, as well as specific applications in industrial and some consumer applications.

Samples are available today with initial pricing set at $3.00-$3.50 in 1000-unit quantities.

A new dual-PLL clock synthesiser supports applications such as PC peripheral devices, consumer electronics and embedded controller systems such as Texas Instruments’ DLP technology.
Alliance Semiconductor is sampling the ASM3P2853A, a dual-PLL clock synthesiser supporting applications such as PC peripheral devices, consumer electronics and embedded controller systems such as Texas Instruments’ DLP technology. The ASM3P2853A is a versatile spread spectrum frequency clock generator that reduces electromagnetic interference (EMI) at the clock source. This allows for significant system cost savings by reducing the number of circuit board layers and shielding that is required to pass EMI regulations.

Spread spectrum clocking technology can virtually eliminate EMI filter networks and ferrite beads, with an added benefit that circuit board traces can be routed more effectively, enhancing design flexibility and layout.

The ASM3P2853A modulates the output of the PLL in order to spread the bandwidth of the synthesised clock, thereby decreasing the peak amplitudes of its harmonics.

This results in significantly lower system EMI compared with the typical narrow band signal produced by oscillators and most clock generators.

Lowering EMI by increasing a signal’s bandwidth is called spread spectrum clock generation.

‘Spread spectrum clocking is definitely a good insurance policy’, said Nelson Arata, Product Marketing Manager for Alliance’s Analogue and Mixed Signal Business Unit.

‘Experienced designers know that EMI can be an 11th hour nightmare.

‘Spread spectrum capability will help the system designer sleep better knowing that his system has up to 6dB of additional EMI clearance’.

Packaged in an 8-pin SOIC, the ASM3P2853A provides a 50MHz spread spectrum clock and a low jitter 48MHz USB clock from a 25MHz crystal source.

Samples are available today, with initial pricing set at $1.50 in 1000-off quantities.

A new 14bit LVDS serialiser/deserialiser saves system cost and board space in consumer electronics products.
Texas Instruments has introduced a 14bit low-voltage differential signalling (LVDS) serialiser/deserialiser (serdes) that saves system cost and board space in consumer electronics products. The device supports a phase-locked loop (PLL) range of 10 to 100MHz without needing external PLL components. It is suitable for a vast array of consumer applications requiring bidirectional data flows, such as memory cards where data can be written as well as read.

The SN75LVDT1422 full duplex serdes reduces system space and component requirements by incorporating in a single device a 14bit serialiser and 14bit deserialiser, each operating independently.

The serialiser accepts 14 transistor-transistor logic (TTL) input lines and generates two LVDS high-speed serial streams plus one LVDS clock signal.

The deserialiser accepts three LVDS input signals, including two high-speed serial streams and one LVDS clock signal, and drives out 14 TTL data signals plus one TTL clock.

The LVDT1422 provides three termination resistors for the differential LVDS inputs, thereby minimising cost and board space, while providing better overall signal integrity.

The LVDT1422 is available now in a lead (Pb)-free 64-pin thin quad flat package (TQFP) from TI and its authorised distributors.

The device is priced at $3.70 in 1000-piece quantities (suggested resale pricing).

The NB4N507A is the first in a series of fully integrated PLL ICs designed to replace expensive crystal oscillators for clock generation in a wide variety of consumer and networking applications.
With more than 30 years of experience designing cutting-edge, high-precision, differential timing devices, ON Semiconductor has released the NB4N507A - the first in a series of fully integrated phase lock loop (PLL) ICs designed to replace expensive crystal oscillators for clock generation in a wide variety of consumer and networking applications. A pioneer of positive emitter coupled logic (PECL) signalling, ON Semiconductor’s latest family of PLL ICs offers performance compatible with the most widely used crystal oscillators at a fraction of the cost. For applications ranging from VGA graphics cards to Fibre Channel clock generation, the traditional method for generating the master clock signal has been to implement a single crystal oscillator.

Historically, crystal oscillators have offered better jitter performance than silicon-based devices.

These canned oscillators are complex to manufacture, and so are relatively expensive and require long lead times - sometimes up to 20 weeks.

ON Semiconductor’s NB4N507A is a high-performance silicon PLL that delivers jitter performance comparable to crystal oscillators but offers far more design flexibility, a lower overall cost and greatly reduced lead times.

With accuracy of 100ppm, the NB4N507A is a preferable alternative to crystal oscillators with similar stability.

‘ON Semiconductor has developed a superior silicon replacement solution for crystal oscillators’, said Bill Schromm, ON Semiconductor Vice President and General Manager of High Performance Analogue Products.

‘Utilising a fully differential bipolar design methodology, ON Semiconductor’s NB4N507A PLL offers inherent noise immunity and full industrial temperature operation not obtainable by competitive CMOS PLL clock generation devices’.

The NB4N507A generates a clock signal ranging from 50 to 200MHz via an inexpensive reference crystal.

With a maximum root mean square (RMS) period jitter of less than 10ps, it delivers half the jitter (or noise) of competitive silicon PLL products.

Because the NB4N507A is fully configurable, it provides true design flexibility.

For example, a single device can be used to generate different frequencies within a system and can be reused on future designs regardless of changes in timing requirements.

In addition, silicon-based ICs like the NB4N507A are inherently much simpler to manufacture which leads to lower costs and vastly lower lead times.

The NB4N507A is available in a 16-pin SOIC package and priced at $1.50 per unit in 1000-unit quantities.