Jon Titus Blog

The March 2010 issue of Design News magazine includes a hands-on review of the Altium NanoBoard 3000 development hardware and software. Look for the "Lab Rat" column in the print issue. The online review includes more information and analysis, plus tips on how to get off to a good start. I enjoyed working with the hardware and software and found both easy to use. The US price for the kit: $ 395. You get a lot for the money.


The NanoBoard 3000XN used for this review included a Xilinx Spartan-3AN FPGA (XC3S1400AN-4FGG676C). Altium also offers a NanoBoard 3000AL with an Altera Cyclone III FPGA and a NanoBoard 3000LC with a Lattice ECP2 device. Each board gives designers memory, and a wide range of devices that include serial, E...Read More

Engineers understand the concepts involved in building a micro electromechanical system (MEMS) on a silicon wafer. Successive layers of silicon undergo chemical etching to create a structure that can serve as an accelerometer, motor, lock, antenna switch, or other micro device. After the etching runs its course, a production step encapsulates the MEMS to protect it from contamination by dust, dirt, chemicals and other materials. That last process can require several additional steps.

Baolab Microsystems of Terrassa, Spain, has devised a way to create a MEMS inside a CMOS wafer, and the new process involves faster and fewer process steps than existing MEMS fabrication techniques that build a MEMS on a wafer's surfacer.  This new process reduces the costs of a MEMS by up to two thirds.

Silicon Laboratories has unveiled a wireless MCU aimed at low-power circuits in smart-home products and smart meters. This family of RF-MCU chips will operate for long periods on battery power, so I expect to see it in portable equipment, too.

The Si10xx RF MCU family has at its heart an 8051 core (25 MHz), and an EZRadioPRO transceiver that can operate from 240 to 960 MHz with an output power as high as 20 dBm. Depending on the Si10xx device, engineers can have as many as 64 kbytes of flash memory and an ADC with up to 12 bits of resolution. On the power side of the "equation," the RF MCU family offers an active-mode current consumption of 160 microamps per megahertz, which refers to MCU clock frequencies, not to RF-communication frequency! In sleep mode, the chips consume 615 nA with an active 32.768 kHz real-time clock (RTC) and down to 315 nA with an active...Read More

Unfortunately, NXP does too good a job of hiding the LPCXpresso information on its Web site. Run a site search and you get links to several pages of information. Good luck with that. I thought the NXP home page would have a direct link. Here's where to go for more information: ics.nxp.com/lpcxpresso/. At the top of the page on the left side, look for "Get LPCXpresso."

Or you can do...Read More

Electrical engineers probably remember they can switch currents faster than voltages, which is why some designers prefer current-output digital-to-analog converters (DAC) over their voltage-output cousins. The relatively low impedances of current nodes allows for high-frequency switching and signaling operations. A current-feedback op amp, for example, can have a slew rate of over 1000V/μsec.

OK, so you're not convinced that a current-feedback (CFB) op amp has advantages over the standard voltage-feedback (VFB) op amps we love and use. Here's the way Analog Devices put together a brief comparison of the two types of op amps in a "Rarely Asked Questions" page labeled, "VFB or CFB that is the question!"

First the design equations used for voltage feedback amps work equally well for current feedback amps, so nothing new to learn ther...Read More

I breadboarded a microphone pre-amplifier circuit and it worked well until I added a circuit that used the audio output to drive an LED bar-graph display. Now, as the LEDs turned on or off, I could hear a click on the audio output. The audio and bar-graph circuits had plenty of decoupling capacitors, and I had used short connections, so coupling of the digital switching signal into the audio circuit seemed unlikely. My wife got tired of hearing me repeat "Test 1 2 3, test 1 2 3..," so I disconnected the microphone's output signal and fed the preamp directly with a low-frequency triangular wave that exercised the bar-graph display. Now I could hear the clicks without talking. Still I couldn't find their source.

But I had reviewed only the audio portion of the circuit and overlooked the +5V power for the LEDs that also supplied the bias current for the electre...Read More

Ed Sutter, the fellow who created MicroMonitor (uMon), an open-source embedded-system boot platform, sent me a note about his newest software, uCon, an embedded system console. Although many people think of serial ports as old fashioned, or even dead, those involved with embedded systems consider them much alive and useful.

To help developers take better advantage of serial ports, Ed's uCon acts like a terminal emulator that also works with remote networked computers, or "backends," to let them connect with a development system or prototype as a telnet or ssh client.

According to Sutter, uCon can operate as a telnet server on a host PC and then let remote clients connect to the PC and virtually connect to the same COM port that the local uCon session has connected to. This technique lets a developer or engineer work locally with a development system thro...Read More

An old economist gave some sage advice to a young grad student. "Son," he said, "give people numbers and dates, but never both at the same time." Information from many manufacturers must come from economists-turned-marketers because it often lacks important details.

Here's a case in point, with names removed to protect the guilty. I received a press release about new measurement devices. The release contained almost as much information about the company as about the new products. And the release came with no link to a product data sheet and no block diagram or photograph.

I asked for and received a link to a 2-page data sheet, but it lacked critical information such as the size and voltage of the battery used as an optional power source. Although the data sheet explained users can "configure" the device in several ways, it doesn't ex...Read More

I started to work with some new FPGA-design software that seemed to take a long time to "build" a simple LED-flasher demonstration project. I let it run for about 45 minutes while I answered emails and had a conference call.

When I took another look, I saw something flash in the corner of the software's display area, but it appeared only briefly every 15 seconds or so. That made it impossible to see what the short message said. The message also appeared superimposed on other information, which increased the difficulty to read it.

That's when I thought about using my camcorder to record the display so I could play it back and see what the message said. I recorded about 15 seconds of video, loaded the video into my iMac's iMovie software and slowly scanned through the frames. Then I saw the brief superimposed image of "Scanning JTag ports..."...Read More