DAC Design Opens Up 70% More Board Space

The nanoDAC devices lower system cost by integrating an on-chip reference. The flagship product, the AD5664R, offers low power consumption (5mW at 5V, including reference), suiting it for industrial and communications products (e.g., PLC cards, analog I/O boards, and base stations) that require high resolution in minimal board space.

The other seven nanoDAC converters offer pin-compatible 12 to 16bit resolution in dual and quad configurations with and without on-chip references. All devices have a power-on reset and per-channel power-down mode that, in the quad-channel devices, reduces the device’s current consumption to 480nA at 5 V. In addition, the dual-channel devices offer hardware LDAC and CLR functionality. An on-chip precision output amplifier enables rail-to-rail output swing.

Single-chip PoE controller

National Semiconductor Corp. introduced a single-chip PoE controller for higher-power PoE applications. The LM5072, which integrates a programmable power interface port and a pulse-width-modulation (PWM) controller, allows designers to operate PoE appliances at higher power levels than standard IEEE 802.3af devices.

Because the LM5072 integrates programmable current limiting, it can draw up to 25W from a PoE-enabled port (see the figure). Many emerging PoE applications require power that exceeds the limit of the existing standard. For standard 802.3af Powered Devices (PDs), the current may be programmed to any value between 150 and 800 mA, or the programming resistor can be simply disconnected to switch the LM5072 to the default mode with 440 mA maximum current draw.

The controller, which features max input voltage and current ratings of 100V and 800 mA, also supports applications that accept power from auxiliary sources. National will demonstrate the LM5072 at PCIM Europe (May 30th - June 1st, Nuremberg, Germany) in Hall 12, Booth 124.

Self-contained FlexRay signal analyser

Yokogawa’s FlexRay signal analyser delivers physical-layer waveform observation and protocol analysis for the FlexRay in-vehicle local-area network. Based on the company’s DL7400 Series of digital oscilloscopes, the analyser lets users capture FlexRay Bus signals with a variety of dedicated triggers. They can also carry out analysis and troubleshooting on parameters such as surge voltage, noise, level fluctuations, and other sources of error.

Once the signals are captured, the waveforms are displayed along with a frame containing a list of analysis results. In addition, users can zoom in on any of the frame waveforms. Because the frame waveform at the cursor in the list is automatically displayed, users can observe the bus signals simultaneously with the analysis results. This makes it easier to determine what effect noise-level fluctuations have on communications data.

Auxiliary functions are available to support analysis; results can be saved to a file in text format. The appropriate FlexRay bus signal is captured by specifying the trigger bit conditions, including frame start, payload preamble, null frame, sync frame, startup frame indicators, frame ID, cycle count, payload data frame, or combinations of these. Triggers can also be activated on combinations of the FlexRay bus-signal bit conditions and other analogue signals, or CRC errors on the FlexRay bus.

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