News and New Products

Popularly priced scopes’ display-update rates outpace competition

By Dan Strassberg, Contributing Technical Editor -- EDN, 2/25/2008

Agilent Technologies has expanded its MSO (mixed-signal oscilloscope)- and DSO (digital-storage oscilloscope)-product lines with 10 models in the next-generation InfiniiVision 7000 Series. The units deliver what the company calls an unparalleled deep-memory display-update rate of 100,000 waveforms/sec. The new series offers bandwidths as high as 1 GHz, analog-signal-sampling rates as high as 4G samples/sec on each active channel, and memory depths as great as 8M points/channel with half of the analog channels and none of the MSOs’ digital channels active. All models are in 7-in.-deep packages that weigh 14 lbs and feature the industry’s largest displays—12.1-in. XGA (1024×768-pixel) LCDs whose area is more than 35% greater than those of competitive scopes.

To appreciate how much faster the 7000 Series units update their displays than do competitive instruments, you need to perform a side-by side comparison, and you may initially wonder why Agilent makes such a big deal of display-update rate. But if you wait a few minutes and closely observe the displays, you should be impressed. In a demo at EDN’s offices, a glitch appeared on the 7000 Series MSO display after about 3 seconds, whereas it took a competitive MSO more than five minutes to display an identical glitch in the same signal. In fact, the glitches occurred periodically at a low duty cycle, but, if you wait a predetermined interval for the glitch to appear on screen, the smaller the fraction of the time the scope is “blind,” the higher its probability of displaying such a glitch. “Blind time” refers to periods when a scope processes data it has already acquired and can’t acquire new data. In the 7000 Series, Agilent has dramatically reduced blind time and has thus correspondingly increased the percentage of time during which the scope can acquire new data.

The math says that we might occasionally have had to wait for more than two hours for the competitive scope to display the glitch. Joel Woodward, the Agilent senior product manager who conducted the demo, says that measurements he made at his office confirmed his two-hour prediction. His point, though, was that if we hadn’t known that the glitch existed, it was highly unlikely that we would we have waited long enough to notice it. Yet, finding infrequently occurring glitches that you don’t know exist is a key function of scopes used for troubleshooting. Because they spend so much more of their time on signal acquisition, the 7000 Series scopes dramatically reduce the time required to find glitches, metastable states, and other elusive phenomena. And because few engineers will wait for hours while nothing seems to be happening, the 7000s can reveal problems that competitive units simply miss.

Agilent also boasts that the 7000 Series offers the industry’s most comprehensive suite of applications, including serial decoding and triggering for I²C (inter-IC), SPI (serial-peripheral interface), CAN (controller-area network), LIN (local-interconnect network), and FlexRay buses; RS-232 and other UARTs; and rapid core-assisted debugging of designs that use Xilinx and Altera FPGAs. Other application-oriented features include segmented memory for analysis of laser pulses, radar bursts, and serial packets; offline PC viewing and sharing of previously acquired scope data; and RF-contextual viewing of scope data using vector-signal-analysis software.

US prices for InfiniiVision DSOs and MSOs range from $6950 for a 350-MHz-bandwidth unit with two analog channels to $17,900 for a 1-GHz-bandwidth MSO with four analog channels and 16 logic channels. A 500-MHz DSO with four analog channels costs $11,050. All analog-only units contain the MSO hardware. To activate the MSO capabilities, you simply purchase a license.