[Engineering Feature] Oscillators Face The Final Frontier
High-reliability oscillator design for satellite systems poses many challenges to the engineering community. The custom nature of the design efforts as well as the quality requirements tend to lead to large, complex specifications that drive cost, design cycle time, and overall product lead time. Materials utilized in design and construction are also limited by environmental constraints such as outgassing, radiation, the use of pure tin, and shock/vibration...
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David Bail
[Technology Report] Match Multicore With Multiprogramming
Across the embedded landscape, the design credo has become “more cores.” However, challenges remain when it comes to the software side. Some hardware architectures can deliver dozens of cores, while others hit thousands of cores. Unfortunately, applications don’t always port easily across different architectures. For the low end of the embedded space, single-core solutions will remain. It’s still possible to move up the power and performance curve by moving to...
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William Wong
[Leapfrog: First Look] Tool Automates Power Optimization Of Embedded SoC Memories
System-on-a-chip (SoC) design teams have long labored to optimize their creations for power, but doing so in the memory portions of the devices has lagged behind. Today’s memory-IP (intellectual property) providers build complex power-management schemes into their products, yet the design of the control logic to take maximum advantage of these schemes is daunting. Attempts to get a handle on dynamic power consumption using sleep modes are...
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David Maliniak
[Leapfrog: First Look] Nonvolatile Storage Doesn't Require Transistors
The CMOx nonvolatile memory technology from Unity Semiconductor targets storage-class memory applications. CMOx is based on new materials in the semiconductor process called conductive metal oxides that use the movement of ionic charge carriers to store information. With 64-Gbit chip capacity on the horizon, it looks to be a challenger to NAND flash. The technology employs a multi-layer, multi-level cell (MLC) approach that gives...
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William Wong
[Design View / Design Solution] Take The Guesswork Out Of Debugging
In the classic board game Battleship, an adversary arranges a fleet of tiny, plastic combat vessels on a grid that’s hidden from view. After an analogous fleet is set up on a separate grid, the objective is to guess the locations of the opponent’s boats. Likewise, the opponent’s goal is to divine the whereabouts of your miniature ships. The game proceeds with ...
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Matthew Gordon
[Ideas For Design] Triple-Current-Modulation Delta VBE Thermometry Cancels Ohmic Error Sources
Delta VBE-based ( VBE) thermometry1,2,3,4 is based on this classic bipolar junction I/V/T relationship: For an ideal transistor, the VBE corresponding to ratiometric change in collector current (I2 / I1) is exactly proportional to absolute temperature: VBE = 198.4 µV * °K * LOG10(I2 / I1). Because cheap, common, and robust small-signal transistors conform closely to the ideal model, circuits that exploit the “PTAT (Proportional...
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W. Stephen Woodward
[Ideas For Design] Logic-Level Signals Shifted To Dim -48-V LED Driver
The main source of power in a telecommunications system is -48 V. This source’s negative polarity and its large magnitude with respect to ground pose a challenge when designers want to use low-power ICs in the telecom system’s application circuits. Fortunately, the emergence of high-voltage ICs—with operating voltages of 75 V and higher—has enabled the use of simple biasing techniques in designing circuits for -48-V systems. The technique described here provides...
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Ahmad Ayar
[Ideas For Design] Seamless Power Switcher And Battery Charger Solution Targets Portable Devices
In today’s world, there are many applications for portable devices. These devices must have extremely low or no battery drain when turned off and need to charge their on-board batteries when connected to an external power supply, whether the device is turned on or not. This circuit provides seamless switching from batteries to external power and provides a simple charging solution. In addition, there are several output signals for a microcontroller (MCU). This...
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Jim Wilson
[Editorial] Web 3.0 Promises New Ways To Analyze And Share Data
Just when you thought it was safe to navigate the social media seas of the Web, along comes the next big wave. Dubbed Web 3.0 or the Semantic Web, these ideas promise new ways to create, massage, analyze, and share data. At the recent Web 3.0 Conference in New York City, I got a taste of what’s to come and thought about how some of these ideas might be useful to the design engineering community. VISITING CALAIS During his...
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Joseph Desposito
[POV: Point Of View] VME And VPX—Moving Forward Together In Military/Aerospace Apps
As many designers familiar with military and aerospace applications know, VME has been the predominant form factor for more than 25 years. Because of its adaptability, ease of maintenance, and ruggedness, among other benefits, VME positioned itself extremely well against competing architectures years ago. Even today, in the face of upcoming VPX/VXS products, VME will have a significant role to play in the future of military and aerospace applications. ...
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Frank Phelan
[Pease Porridge] Bob's Mailbox
HI BOB, I read your response to Arthur Williams in the April 23 column (“Bob’s Mailbox”). The answer as to whether or not to remove the ground plane underneath inductors is: it depends. If the inductors are cans or toroids, it does not matter as the fields are contained inside the inductor. If the inductors are air wound or chip inductors, it might be best to try...
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Bob Pease
[TechView: Analog & Power] 50-MHz Op Amps Self-Calibrate Offset
The MCP65X 50-MHz rail-to-rail operational amplifiers from Microchip Technology include an on-chip “mCal” calibration circuit that calibrates offset voltage at powerup or on-command. An internal power on-reset detector or a signal on an external pin initiates calibration. Self-calibration provides a lower initial voltage offset than conventional op amps, along with a means to continually control drift over time and temperature, Microchip says (...
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Don Tuite
[TechView: Analog & Power] USB Isolator Simplifies Safety In Medical, Industrial Apps
In embedded applications that use the PC architecture, the USB interface has supplanted RS-232 for remote control, diagnostics, firmware updates, configuration of operational settings, and data exchange. As with its predecessor, one drawback to USB in medical and certain industrial applications is the lack of a provision for isolation in the basic standard, though mains-powered patient monitors require it for safety cer tification, and...
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Don Tuite
[Engineering Essentials] The Dark Force Of Evil In Electronics: Electromagnetic Interference
Is there an electronic product or circuit that’s not susceptible to electromagnetic interference (EMI)? For that matter, are any devices EMI-free? Simply put, no. EEs wish it wasn’t the case, of course, but it’s a fact of life in electrical engineering— and it’s one of those things they typically don’t teach you in school. Most engineers find out about EMI on the job, where expunging it often takes more time than the original design itself. And don’t...
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Louis E. Frenzel
[Electronic Design Products] Converters Provide Crucial Help In EMI/RFI Shielding
Manufacturers of electronic devices employ electromagnetic interference (EMI) and radio-frequency interference (RFI) shielding to protect sensitive digital circuits from external emissions that can impair product performance, as well as to contain the potentially harmful emissions that come from their products (see “The Dark Force Of Evil In Electronics: Electromagnetic...
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Craig McClenachan
[Lab Bench] My E-mail Ate My Homework
I’m becoming more forgetful these days— or rather my e-mail is (Fig. 1). Like many of you, I work for a company that limits the lifetime of e-mail. At first, this seems reasonable. It saves space, even though hard-disk prices per terabyte are falling faster than a fully populated NAS box. It’s also a great way to eliminate evidence. This policy has some unintended consequences, though, for...
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William Wong
