The Best of SemiApps

The Ultimate Resource for Building Next-Generation Systems

SemiApps allows electronic design engineers to easily and quickly find product vendors who provide chipsets, application-focused ICs, customizable or programmable platforms, and specialized components for particular applications. Each month we bring you our best on-line postings (www.semiapps.com/thismonth). Our choices, as presented here, are based on what other engineering readers like you looked at most during the previous few weeks.

Readers Choice: The Best New Application-Specific ICs

Among the most popular devices posted this past month is the LTC4268-1 power-over-Ethernet controller from Linear Technology. At the heart of the device is a high-performance switching regulator optimized for isolated PoE applications. The LTC4268-1 incorporates Linear Tech’s patented NoOpto feedback topology to provide full IEEE 802.3 isolation without the need for optoisolator circuitry. A feedback amplifier senses the output voltage through the transformer winding during the flyback period and uses this voltage to tightly regulate the output.

The LTC4268-1 offers a PD (powered device) controller front end for use in hostile PoE environments. By incorporating a precision dual-current limit, the PoE unit ensures trouble-free interoperability with any power-sourcing equipment (PSE). The LTC4268-1 can handle 750 mA with the lowest on-resistance (0.55 Ω typ) hot-swap MOSFET on the market. The FET on-resistance minimizes device heating and improves overall efficiency.

Targeting automotive powertrain systems, a new microcontroller from Renesas Technology also drew significant interest from visitors. Built with a 90-nm process, the 200-MHz SuperH chip with on-chip flash memory is said to be ideal for developing the precise real-time engine and transmission control to meet stricter emission regulations.

The SH72546-RFCC device is a preproduction unit optimized for control program development, offering a set of features tailored to aid software design and debug. It forms the basis for an upcoming mass-production product family that will have performance, package, and pin arrangement compatibility.

Engineering Blogs of the Month

In our most popular blog of the month, Fairchild Semiconductor’s Michael Weirich raises a very interesting question: Which lighting source will win out among several highly competitive lighting technologies?

Referring specifically to the fluorescents, the halogen lamp, the increasingly popular LEDs, and the traditional incandescent, our blogger reminds the design community that there are notable differences in cost and considerations that need to be taken into account in terms of their lifetimes and energy-efficiency savings. “In the past few years, more and more people worldwide are recognizing that saving energy is an important issue,” said Weirich. “If one keeps in mind that lighting takes about 12 percent of the electrical energy generated worldwide, it is obvious that increasing efficiency in lighting applications can save a large amount of energy and have a strong impact on the global environment,” adds our blogger.

Another attention-grabbing blog comes from Keith Odland, a Silicon Laboratories product manager that focuses on the company microcontroller products. Touching a nerve with design engineers, Odland says, “I have noticed over the past several years a very disturbing trend in the area of microcontroller documentation. I call it the datasheet gap. It is an insidious problem that wastes more cumulative embedded designer cycles than writing your own TCP/IP stack. Simply put, it is the balance of useful information between what is displayed on the first page of a datasheet and that contained in the numerous pages, tables, graphs, and footnotes within the datasheet.”

Design Classics Library: Application Notes of Note and More

Jennic’s IEEE802.15.4 voice reference design enables secure full duplex transmission of speech with long battery life for use in point-to-point and large wireless sensor networks.

Jennic’s IEEE802.15.4 audio reference design provides several key benefits for audio applications low-power operation with instant response and long standby battery life; secure speech with 128-bit AES encryption; simple development with no complex profiles, a range of greater than 200 m, and more addressable nodes than Bluetooth, making it suitable for public address or broadcast applications. Applications include emergency services’ helmet to PMR radio, providing a fireproof and secure alternative to cables for communication from helmet to radio, and for applications including VoIP headsets and low-power door intercoms.

Marty Gold