As more consumer and commercial products are introduced with High-Definition Multimedia Interface (HDMI) cable connections, the resulting EMI issues related to HDMI cable emissions have continued to be problematic for product designers and EMC engineers. It is very common to have one, or more, added HDMI cables cause a product to fail the radiated emissions (RE) test. The … [Read more...]
Troubleshooting ESD in Floating Medical Grade Circuits
Introduction Medical devices must be designed with proper isolation of patients from earth. For that reason all medical products have floating circuits. This means that the circuit ground is isolated from the earth ground. ESD protection in floating circuits with isolated grounds can be very challenging. Sometimes conventional ESD protection methods may not work. It is … [Read more...]
Get the Job Done – Pocket-Sized 20 MHz Wireless Oscilloscope
In photography, they say the best camera is the one you have with you. The same may be said for simple electronic test equipment. For example, I was recently working with a client and we needed to verify Vcc voltage on one of their boards. Not having a DMM quickly available in their lab, I pulled out a tiny DMM from my troubleshooting kit, no larger than a pack of cigarettes. … [Read more...]
Review: EMC – Methods, Analysis, Circuits, and Measurement
Electromagnetic Compatibility - Methods, Analysis, Circuits, and Measurement, David Weston, CRC Press, 2017 (3rd edition) While I've reviewed many books on EMC, this one by David A. Weston, is the most complete in coverage yet. The 1157-page book covers not only basic and advanced theory of EMC, but includes product design, commercial and military measurement techniques, and … [Read more...]
2017 DoD E3 Program Review – After Action Report
By Brian Farmer on behalf of the DSO E3 Program Review Team After a five-year hiatus, the 2017 Department of Defense (DoD) Electromagnetic Environmental Effects (E3) Program Review was held April 3 - 7 at Lackland Air Force Base, San Antonio, TX. Over 60 technical presentations were delivered throughout the week, three working groups were convened, 12 exhibitors displayed … [Read more...]
The Importance of Layout in ESD Suppressing Diodes
ESD protection of sensitive electronics via transient voltage suppression (TVS) diodes is becoming a common circuit technique across industries. Signal lines in a circuit that are accessible to humans by touch (such as USB, HDMI, etc.) require ESD protection on all sensitive signal lines that are input to some IC’s. Placement of the ESD protection diodes on the circuit board … [Read more...]
Measuring Common Mode Versus Differential Mode Conducted Emissions
When faced with excessive conducted emissions from switching power supplies, one of the first things to investigate and to determine the adequacy of is the power line filter. Line-powered switching supplies generally have both common mode and differential mode sections of the filter as shown in the generalized schematic in Figure 1. When using a line impedance … [Read more...]
ESD Effects of Digital ICs
One issue I see fairly often with unshielded consumer or commercial products is CPU resets during periods of immunity testing, such as during electrostatic discharge (ESD) testing. Untreated, this can lead to field failures and associated customer satisfaction issues. The remedy is usually quite simple and IC manufacturers even mention the solution, but it’s usually buried … [Read more...]
Energy Harvesting is Not Fiction Anymore
“About what we did dream today, are the ideas from tomorrow. The tomorrow ideas are the products from the days after tomorrow.” Our environment is changing and everything is becoming “electronified”. Our glasses, our hand gloves, shirts, shoes etc., can be connected already today with our smartphones and can send commands to the machinery surrounding us. We want this comfort, … [Read more...]
Narrowband Versus Broadband Harmonic Signals
Radiated and conducted emissions measurements are often comprised of both narrowband and broadband sources. So what differentiates “narrowband” and “broadband” signals? Narrowband Versus Broadband Signals The definition of whether a signal is narrowband or broadband as measured using a spectrum analyzer, depends entirely on the receiver bandwidth (resolution bandwidth, or … [Read more...]
- « Previous Page
- 1
- …
- 12
- 13
- 14
- 15
- 16
- …
- 26
- Next Page »