Avnet Memec adds Ispclock5400D ICs to its range

Avnet Memec has extended its portfolio with Lattice's Ispclock5400D family of differential clock distribution ICs, featuring the Cleanclock ultra-low phase noise PLL.

The Ispclock5400D family contains the six-output Ispclock5406D and the 10-output Ispclock5410D.

The Flexiclock output section of the Ispclock5400D devices supports multiple logic standards and dual skew control features.

The configuration of each device is held in on-chip non-volatile memory that is reprogrammable through a JTAG interface.

Certain aspects of the device can be modified on the fly via an I2C interface.

Design for the devices is supported in the Lattice PAC-Designer software tool.

The Ispclock5400D family is said to enable designers to reduce cost and complexity in their differential clock networks, while providing the flexibility for late design changes, even after board assembly.

Typical applications for the Ispclock5400D devices include supplying high-quality reference clocks to high-speed serialised communication ICs that use Serdes technology and the consolidation of components, such as fan-out buffers and zero-delay buffers, typically used for distributing high-frequency clocks in a circuit board.

The Ispclock5400D devices integrate an ultra-low phase noise Cleanclock PLL, including an on-chip programmable analogue filter and a programmable VCO with input clock frequencies up to 400MHz.

The PAC-Designer software tool automatically determines the parameters of the PLL, depending on the input and output clock frequencies.

This wide-band Cleanclock PLL is compatible with the Spreadspectrum clocks required for distributing PCI Express and SATA clocks.

The phase noise of the PLL is low enough to be suitable for sourcing clocks to Serdes chips.

The Ispclock5400 family provides in-system programmable Flexiclock differential outputs.

Each output can be configured to interface with a number of logic standards, such as LVDS, MLVDS, HCSL, LVPECL, HSTL and SSTL.

The output clock can be individually skewed using the phase angle and time skew mechanisms.

In addition, the skew can be changed dynamically in-system through an I2C interface.

The need for a reference clock source for FPGAs and ASSPs with Serdes (such as the new LatticeECP3 FPGA family) has traditionally been addressed with expensive crystal oscillators with differential outputs.

The Ispclock5400D device enables the use of a lower-cost, lower-frequency CMOS oscillator clock source, reducing the overall cost of implementation because the cost of a differential interface oscillator is higher than a CMOS oscillator and the Ispclock5406D device together.

Simple low-cost differential clock distribution requirements are determined by the type of logic interface, frequency, jitter and number of outputs.

Discrete off-the-shelf clock distribution buffers provide point solutions for each of these.

However, a typical system with multiple cards requires many types of clock distribution buffers from different vendors, resulting in a more expensive bill of material and increased inventory management costs.

Since the Ispclock5400D devices can be programmed as a fan-out buffer or a zero-delay buffer, along with a number of outputs, they can satisfy diverse clock distribution requirements.

The resulting design is not only lower in cost but also enables designers to compensate for timing errors owing to trace lengths or other device-related timing variations.

Consequently, designers can standardise on Ispclock5400D devices across all of their designs.

Ispclock5400D designs can be implemented using a GUI provided in the PAC-Designer version 5.0 software tool.

The PAC-Designer 5.0 tool can be downloaded for free from the Lattice website.

Samples of the Ispclock5406D device (48-pin QFNS package) and the Ispclock5410D device (64-pin QFNS package) are available immediately.

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