Pentek unveils multi-frequency clock synthesiser

When synchronous sampling is not required, and when sampling rates and bit counts are relatively low, A/D and D/A systems are often clocked by on-board oscillators.

However, for larger multi-channel radar and beam-forming systems, synchronous sampling is mandatory.

In addition, as A/Ds achieve 16-bit resolution and exceed sampling rates of 200MHz, a far more functional, flexible and precise clock is required, which is what Pentek's 7190 provides.

'In many cases, the 7190 module frees the customer from having to devise a custom clock generation scheme,' said Rodger Hosking, vice-president of Pentek.

'Most other alternate clock source solutions are bulky and are not well suited for deployment.

'As a PMC module, the 7190 delivers a compact, clean and flexible clock solution for fielded systems,' he added.

'In digital signal processing, data acquisition or recording system applications, accuracy and purity of the sample clock are critical and the connection to a very high precision source is essential,' said Mark Wilson, general manager of clocks and timing products at Texas Instruments.

'We are pleased that Pentek chose TI's CDC7005 low phase noise clock synchroniser to reduce the amount of jitter in the Model 7190 output clocks,' he added.

A key feature of the 7190 is that all eight output clocks are phase locked to an external frequency reference, typically 5MHz or 10MHz.

It uses four TI CDC7005 clock synchronisers, each controlling a quad-frequency voltage-controlled crystal oscillator (VCXO).

Each CDC7005 is programmed to select any one of its four VCXO frequencies, providing a total of 16 different VCXO frequencies for the board.

Each of these frequencies can then be divided by one, two, four, eight or 16, resulting in 80 different clock frequency choices.

Up to five different frequencies from this set can be delivered to the eight front-panel SMC output connectors, or a single identical clock can be sent to all eight outputs.

Numerous other combinations are possible, depending upon the specific configuration of the A/D and D/A boards.

The 7190 is also equipped with a non-volatile memory.

Once it is configured, the settings will return to the saved configuration each time it is powered up.

Once a configuration is saved, the 7190 does not require PCI access, which is useful for deployed applications that might not include a host computer.

As PMC is a standard form factor for embedded systems, the 7190 is adaptable to different architectures.

Utilising PMC carrier boards, the 7190 can be transformed into a VME or Compact PCI (3U or 6U) board.

In addition, inserting the 7190 into Pentek's PCI or PCIe (PCI Express) carriers enable the 7190 to be used in a desktop computer.

The 7190 is supported with a Readyflow board support package running under Linux, Windows or VXWorks operating systems.