The switching power supplies that regulate output voltage produce radiated emissions. Our tests compare waveforms that give clues as to how the chargers operate.
FAQ
Characterize EMI from dc-dc converter ringing
Switching power supplies produce radiated and conducted emissions caused by ringing. Oscilloscope and spectrum-analyzer measurements let you see them. DC-DC converters are ubiquitous in most electronic products. While more efficient than linear regulators, they can also produce considerable amounts of interference that can affect nearby circuits. The measurements in this article show how ringing occurs […]
Review: Micsig TO3004 tablet oscilloscope
If you’re looking for a portable oscilloscope for field troubleshooting or for demonstrations, look at the Micsig TO series. Here’s my take on the four-channel 300 MHz variant, TO3004. The Micsig TO3004 oscilloscope (Figure 1) is an 8-bit, four-channel, tablet-sized portable oscilloscope that’s also available with 100 MHz and 200 MHz varieties with two or […]
How to use convolution to implement filters: part 4
A windowed sinc function can implement a low-pass filter, and a two-dimensional convolutional filter can blur or sharpen images. In part 3 of this series, we introduced a low-pass filter based on the Sinc function and described the need for windowing to compensate for sampling and truncation. Q: How can we apply this filter? A: […]
Why engineers need IC ESD and TLP data
Design Engineers need ESD and TLP characterization data to make informed decisions to design robust circuits and systems. Engineers often review semiconductor data among several manufacturers when designing a circuit or system. While two or more ICs may perform satisfactorily under normal operating conditions, they may not perform the same under extreme conditions, such as […]
How to use convolution to implement filters: part 3
A windowed sinc filter outperforms a moving-average filter in the frequency domain. In part 2 of this series, we described a type of convolution filter called the moving-average filter, and we demonstrated that it is effective at removing Gaussian white noise in the time domain but performs poorly in the frequency domain. Q: Do all […]
How to use convolution to implement filters: part 2
A moving-average filter can address white noise in the time domain but performs poorly in the frequency domain. In part 1 of this series, we defined convolution, denoted by the * symbol, and looked at a simple geometrical example of how it operates to produce a new function y(t) from two given functions, f(t) and […]
How to use convolution to implement filters: part 1
Convolution is used in a variety of signal-processing applications, including time-domain-waveform filtering. In a recent series on the inverse fast Fourier transform (FFT), we concluded with a mention of convolution and its application to filtering. Convolution Q: What is convolution? A: Convolution, denoted by * symbol, combines two functions to form a third function in […]
What is second generation beamforming?
Second-generation beamforming refers to advanced designs using more sophisticated signal processing algorithms, larger antenna arrays, and the ability to generate higher quality, more focused beams that dynamically adapt to user movement and changing environments. This article looks at how basic beamforming works and how second-generation beamforming contributes to improved network efficiency. It closes by considering […]
How are NRZ and PAM different in an eye diagram?
Eye diagrams are important tools in telecommunications for analyzing the performance of digital signals, such as noise, distortion, and intersymbol interference. This FAQ compares the non-return-to-zero (NRZ) and pulse modulation (PAM) formats, which are common ways of reading an eye diagram. NRZ represents binary data using two voltage levels, 0 and 1. This results in […]
