Fall 2009 Vol. 18, No. 2

Features Simultaneous synthesis of up to five different clocks Eight SMC clock outputs Ideal for A/D and D/A converter clock sources with typical phase noise of –125 dBc/Hz @ 1 kHz offset All clocks are phase-locked to input reference signal of 5 or 10 MHz Four quad VCXOs allow selection from 16 different base frequencies Output clocks of 1, 2, 4, 8, or 16 submultiples of VCXO base frequencies Output clock frequencies between 50 and 500 MHz

General Information

Model 7190 generates up to eight synthesized clock signals suitable for driving A/D and D/A converters in high-performance real-time data acquisition and software radio systems. The clocks offer exceptionally low phase noise and jitter to preserve the signal quality of the data converters. These clocks are synthesized from an input reference signal using phase-locked oscillators.

Clock Synthesizer Circuits

The 7190 uses four Texas Instruments CDC7005 clock synthesizer and jitter cleaner devices. Each CDC7005 includes phaselocking circuitry that locks the frequency of its associated quad VCXO (Voltage Controlled Crystal Oscillator) to the input reference clock. This reference is a 5 or 10 MHz signal supplied to a front panel SMC connector. Each quad VCXO is programmed to generate one of four base frequencies.

Each CDC7005 generates five output signals. Each signal is independently programmable as a submultiple of the associated VCXO base frequency using divisors of 1, 2, 4, 8 or 16.

The five clock output signals from each of the four CDC7005s are joined into five clock buses. Each CDC7005 output can be independently enabled to drive each bus, thereby allowing any combination of output signals from the four CDC7005s.

Eight front panel SMC connectors supply synthesized clock outputs driven from the five clock buses, as shown in the block diagram. This supports a single identical clock to all eight outputs or five different clocks to various outputs; numerous other combinations are possible.

PCI Interface

Power Up Auto Configuration

The 7190 is equipped with a non-volatile memory. Once configured, the settings return to the saved configuration upon power up. Once a configuration is saved, the 7190 does not require PCI access; this is convenient for deployed applications that do not include a host computer.

For more information including options, such as frequencies of factory-installed VCXOs, and price quotation on the Model 7190, click here.