PAM4 modulation boosts throughput but adds test challenges. The Peripheral Component Interface (PCI) emerged in the 1990s as a parallel bus for connecting computer mainboards and peripheral devices. In 2003, a serial version called PCI Express (PCIe) debuted, with generation 1 offering a transfer rate of 2.5 GT/s. Over the past 20 years, successive generations […]
FAQ
How does a thermocouple work, and do I really need an ice bath (part 2 of 2)?
Modern thermocouple instruments automate the cold-junction-compensation process. Part 1 of this two-part series introduced thermocouple cold-junction compensation (CJC). This part will elaborate on the concept. Table 1, presented in part 1 and repeated here, lists a subset of the NIST voltage and temperature data for the type T thermocouple.Figure 1 shows a typical measurement setup, […]
How does a thermocouple work, and do I really need an ice bath (part 1 of 2)?
Efforts at the Bureau of Standards 110 years ago paved the way for the cold-junction-compensation technique used today. Thermocouples have long been used to make temperature measurements. They are simple, consisting of a pair of wires of dissimilar metals welded together at one end. They are rugged, operate over wide temperature ranges, and generate readily […]
What is jitter and what can I do about it (part 2 of 2)?
Operations on acquired jitter data help quantify jitter values. Part 1 of this article described the oscilloscope eye diagram and unit interval (UI) and focused on a single ideal rising edge with 28 additional edges representing some degree of jitter (Figure 1). We determined the peak-to-peak jitter to be 15 ps, based on the edges […]
The factors of accurate measurements
All measurements need reliable, accurate equipment that’s traceable to worldwide standards. Without that, measurements have no value. From ensuring product quality in a factory to safety to letting every individual use a computer or phone, accurate measurements are critical in every aspect of our lives. In the automotive industry, accurate measurements of components and the […]
What is jitter and what can I do about it (part 1 of 2)?
Measuring and quantifying jitter are the first steps toward controlling it. Jitter is a measure of the timing performance of a digital data stream such as Ethernet, USB, PCIe, or HDMI. It defines when data transitions occur in relation to an ideal waveform. Excess jitter can lead to signal-integrity problems that result in high bit-error […]
Automate double-pulse testing in WBG devices
By automating double-pulse testing of wide bandgap devices such as SiC and GaN power devices, you can cut setup and analysis time. The need to reduce carbon emissions drives investments in electrical technologies, particularly in data centers and electric vehicles. In its most recent Elective Vehicle Outlook report, Bloomberg estimates a 27% increase in global […]
What is GPIB and is it obsolete?
The bus, codified as the IEEE 488 standard, continues to find use in legacy test-system upgrades and in calibration labs. The General-Purpose Interface Bus (GPIB) began life as the Hewlett-Packard Interface Bus (HP-IB). Hewlett-Packard, whose electronic test-and-measurement business has evolved into today’s Keysight Technologies, created the interface in the 1960s to connect multiple instruments in […]
Co-packaged optics: promises and complexities
Integrating optics into the same package as switching ASICs improves signal integrity and increases data rates, but challenges remain. Near-packaged optics could emerge as an interim solution to the problem. The constant need for more throughput in data centers pushes engineers to develop ever-faster optical and electrical links. In addition to designing for more speed, […]
How to make fast and accurate power-integrity measurements
Today’s electronic devices with fast FPGAs, ASICs, and other ICs rely on ever-smaller power rail voltages with tight tolerances. Engineers who incorporate these ICs into their systems need to use oscilloscopes, probes, and measurement techniques that align with today’s tight voltage rail tolerances. Making an accurate ripple measurement with an oscilloscope on a 1 V […]
