Waveform generators generally contain a library of common waveforms, which can be individually accessed and displayed by running a BNC cable to an active analog channel input in an oscilloscope. Most oscilloscopes have, available as an option, an internal arbitrary function generator (AFG), which permits the user to create an endless variety of waveforms and […]
oscilloscope measurements
Measuring phase noise and jitter
Generally, whether one speaks of phase noise or jitter depends upon whether they happen to be a radio frequency or digital systems engineer. Both phenomena are random fluctuations of a time-domain waveform in an oscillator or in a clock. Phase noise is best represented in the frequency domain. It is usually defined as the spectral […]
Understanding bandwidth concepts
Bandwidth has an array of meanings, depending on the context. Often, but not always, the term is applicable to a situation where one frequency is superimposed on, mixed with, or modulates a different frequency. A simple and fundamental example is amplitude modulation and its close relatives, frequency and phase modulation. When speaking of a broadcast […]
How to use oscilloscopes with integrated test instrumentation
Many manufacturers have in recent years have introduced oscilloscopes with integrated test instrumentation. This means that the smaller and lighter oscilloscope enclosure actually houses about five additional test instruments. An example is the Tektronix MDO3000 Series which includes a digital voltmeter, arbitrary function generator, spectrum analyzer, logic analyzer, and protocol analyzer. All this integrated test […]
Understanding sampling modes in digital oscilloscopes
In a digital oscilloscope, the analog signal is at the input, after attenuation/amplification and preliminary filtering such as for ac coupling, goes to an analog-to-digital converter (ADC). Each channel has a separate ADC, each with an external clock. Analog-to-digital conversion takes place by means of sampling. The samples are taken at specific rates and the […]
First 56-GBd optical probes for real-time scopes help troubleshoot 400G PAM4 components
The industry’s first 56 GBd 400G PAM4 optical probe is designed for use with Tektronix DPO70000SX Series real-time oscilloscopes. The new 59 GHz DPO7OE2 single-mode optical probe delivers the performance and advanced debug capabilities designers need to troubleshoot 400G PAM4 components and reduce time to market. Compared to 100G with NRZ modulation, 400G with PAM4 […]
Scope optical modules boast high sensitivity, low noise
Two new optical modules for the Tektronix DSA8300 sampling oscilloscope offer the industry’s highest sensitivity and lowest noise, helpful for analyzing 400G designs moving into production. Tektronix also announced enhanced support for the latest 400G PAM4 TDECQ measurements with a software package optimized for 4 channel parallel processing for high throughput manufacturing test. “As 400G […]
Testing and debugging the I2C digital data bus
“Bus” is an old term derived from conductive elements that are part of an electrical distribution system, generally referring to short specialized conductors separate from the overhead or underground cable. Typically, the old-style buses consist of bare copper bars, often having a rectangular cross-section, firmly mounted in an enclosure and capable of carrying current at […]
Characterizing digital logic signals with an oscilloscope
Transistor-transistor logic (TTL) and complementary metal oxide semiconductor (CMOS) logic are the principal types of integrated circuit-based logic gates implemented in digital circuitry. TTL employs bipolar junction transistor technology while CMOS uses the field-effect transistor concept at the input. TTL consumes far more power than CMOS, which is one reason CMOS has eclipsed TTL as […]
Basics of measurement resolution
In electronic instrumentation, resolution is a measure of the distance in amplitude at which we can distinguish between two points on a waveform. This is not the same as accuracy, which is a measure of how closely a waveform as displayed or measured agrees with the signal at the instrument’s input. One of the principal […]
