Semtech Simplifies the Design of Multiple Line Rate Cards with New Fractional Low Phase Noise Clock

Semtech Simplifies the Design of Multiple Line Rate Cards with New Fractional Low Phase Noise Clock Synthesizer Platform

Industry's best combination clock synthesizer of size, performance and frequency flexibility

CAMARILLO, Calif.--(BUSINESS WIRE)-- Semtech Corporation (NAS: SMTC) , a leading supplier of analog and mixed-signal semiconductors, today announced the general availability of the ACS1790T, a new low phase noise clock synthesizer.

The ACS1790T is a tiny device offering frequency selection better than one part-per-billion on a low phase noise platform with typical RMS jitter below 500 femtoseconds.

The new part is suitable for a wide range of demanding applications including 10G Ethernet, Synchronous Ethernet, SONET/SDH, FibreChannel, CDR, software controlled clock generation and other reference clocks. It can be used either as a stand-alone frequency synthesizer or as a companion chip to the ACS9522T ToPSync® system synchronization solution, generating a low phase noise local reference clock that is aligned to the system timing recovered by the ACS9522T.

As a standalone frequency synthesizer, the ACS1790T offers outstanding flexibility with a 24-bit fractional feedback divider that generates any output frequency with a resolution of 0.5 parts-per-billion (ppb). This allows synthesis of any output frequency within the range of 10 MHz to 200 MHz on the LVPECL output and 2 KHz to 125 MHz on the LVCMOS output.

The part is packaged in a 4mm x 4mm 24-QFN package. All loop components are on-chip simplifying the circuit board layout and making the total solution footprint ideal for space-constrained applications. The combination of a high fractional resolution with a simple serial interface also makes the ACS1790T ideal for use in software-controlled loops where a translated but disciplined or traceable clock is required.

"The ACS1790T represents a key milestone in our mission to provide our customers complete timing solutions," said David Spencer, Marketing Manager for the Semtech Timing Products. "It is our first really low phase noise product and is a great leap forward in performance, perfectly complementing our ToPSync product line and also serving as a versatile stand-alone frequency synthesizer with outstanding performance."

Key Features of the ACS1790 Frequency Synthesizer

  • Very low RMS phase jitter, < 500 fs typical (integrated from 12kHz-20MHz)

  • Flexibly generates any frequency within following frequency ranges with 0.5 ppb precision

    • LVPECL output: 10 MHz - 200 MHz

    • LVCMOS output: 2 KHz - 125 MHz

  • Supports 1G/10G Ethernet, SONET/SDH, E1/T1, PCI Express and many other standards

  • Pin-strapped start-up modes for 1G/10G Ethernet frequencies

  • Simple serial interface for control and configuration

  • 4mm x 4mm 24-QFN package

Pricing and Availability

The ACS1790T product (order code: ACS1790IMLTRT) is available in production quantities and is priced at $9.00 each in 10,000-piece lots. Semtech offers comprehensive design assistance, including field- and factory-based support. Data sheets, volume pricing, and delivery quotes, as well as evaluation kits and samples, are available at

About Semtech

Semtech Corporation is a leading supplier of analog and mixed-signal semiconductors for high-end consumer, computing, communications and industrial equipment. Products are designed to benefit the engineering community as well as the global community. The company is dedicated to reducing the impact it, and its products, have on the environment. Internal green programs seek to reduce waste through material and manufacturing control, use of green technology and designing for resource reduction. Publicly traded since 1967, Semtech is listed on the NASDAQ Global Select Market under the symbol SMTC. For more information, visit

Semtech, Semtech logo and ToPSync are registered marks of Semtech Corporation.

Semtech Corporation
Pauline Cadena, 805-389-2755

KEYWORDS: United States North America California


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