Clock synthesiser cuts the jitter

A Texas Instruments (April 2001-March 2006) product story

Edited by the Electronicstalk editorial team Jun 27, 2005

A new clock synthesiser and jitter cleaner claims the lowest phase noise and jitter in its class.

Texas Instruments has developed a clock synthesiser and jitter cleaner that offers the lowest phase noise and jitter in its class.

The device addresses customers' growing requirement for higher performance and increased design flexibility in applications such as 2.5G/3G wireless basestations, datacommunications, medical imaging, and test and measurement.

The CDCM7005 provides precise, stable frequencies for signal-chain devices such as ADCs, DACs, digital up-convertors and digital down-convertors.

It offers the industry's lowest phase noise of -219dBc/Hz (PLL figure of merit), lowest phase jitter performance of 162fs (LVPECL) and 232fs (LVCMOS), and maximum output skew of 20ps.

This performance allows data convertors such as ADCs to be undersampled at higher input frequencies while delivering the highest signal-to-noise ratio.

The CDCM7005 offers features that maximise design flexibility, including serial peripheral interface (SPI) logic for programming and individual support control.

The device synchronises a voltage-controlled crystal oscillator (VCXO) frequency up to 2.2GHz (LVPECL) to one of two reference clocks to deliver high-frequency, clean clock outputs.

The outputs can be divided by 1, 2, 3, 4, 6, 8 or 16 divide ratios and delivered at LVCMOS and LVPECL levels.

Other useful features include the device's bias voltage (VBB) pin, which allows it to supply the correct voltage to a single-ended VCXO, eliminating the need for external resistors and thereby simplifying the design.

In addition, the CDCM7005 supports frequency holdover mode and fast-frequency locking for failsafe and increased system redundancy.

The 3.3V CDCM7005 is available today in industrial temperature range (-40 to +85C) from TI and its authorised distributors in either a 64-pin, 0.8mm ball-grid array (BGA) or 48-pin, 0.5mm quad flat no-lead (QFN) package.

Suggested resale pricing in 1000-piece quantities is $10.75.

An evaluation module is also available.