News and New Products

Track-and-hold device allows direct capture of signals greater than 10 GHz

By Bill Schweber -- EDN, 5/24/2005

The extremely wideband RTH050 dual track-and-hold device from Rockwell Scientific enables direct conversion of gigahertz-range signals and signal edges with rise times of approximately 20 psec. This unit has small-signal input bandwidth of 15 GHz and supports a sampling rate of 100 to 1000M samples/sec. The differential signal-path device incorporates cascaded track/hold circuits to provide a hold time that is greater than one-half clock cycle, which reduces bandwidth requirements for the subsequent signal-handling chain. Aperture jitter is 100 fsec, and acquisition time is 200 psec. Hold-mode distortion is –42 dB for a 5-GHz signal with 0.5V p-p amplitude, rising to –30 dB for a 7.5-GHz signal; noise is less than 1 mV. Spurious-free dynamic range is 65 dB with a 1.060-GHz, 0.5V p-p signal.

According to Ron Latreille, product-line manager for mixed-signal products, the improved speed of this unit, compared with its predecessors, allows users “to digitize a broader range of signals with no increase in power consumption” at 1.65W. A similar device, the RTH055, also integrates 12-dB attenuators to eliminate the need for external components to scale down signals with excessive full-scale magnitude. The RTH050 sells for $300 (100) and is available in a 13-lead HSD package.

Rockwell Scientific Co LLC, www.rockwellscientific.com.