Using Isolated RS-485 in DMX512 Lighting Applications

Theatrical lighting applications have evolved from lanterns in open-air theatres into the more complex systems available today. Modern lighting equipment includes dimmers, flashing lights, moving lights, colored lights, and gobos. These lighting systems are often controlled over long distances—up to 4000 feet—using the DMX512 communications protocol.

Synchronizing Device Clocks Using IEEE 1588 & Blackfin Embedded Processors

IEEE 1588 defines a protocol to synchronize distributed clocks on a network. The preferred clock synchronization method for many applications, it is cost-effective, supports heterogeneous systems, and provides nanosecond-level synchronization. The ADSP-BF518 Blackfin® processor includes dedicated hardware support for IEEE 1588. This article shows clock synchronization performance obtained using this solution.

Automobile Tail Lamp and Brake Lamp Controller

Light emitting diodes (LEDs) are recently finding uses in automobiles, where they provide signaling, daytime running lights, and interior lighting. As this technology hits the road, manufacturers continue to investigate new ways to apply it, taking advantage of the styling possibilities afforded by LED headlights and taillights.

Isolation in High-Voltage Battery Monitoring for Transportation Applications

Battery stacks for transportation can provide hundreds of volts. These high voltages can prove lethal to human beings—and even lower voltages can damage electronic equipment—so safety is a key concern. Although these stacks are inherently dangerous, they must still communicate with the cell monitoring electronics. Galvanic isolation is thus required to make the communications method safe and reliable.

Phase Response in Active Filters, Part 2: Low-Pass and High-Pass Responses

The transfer function of an active filter can be viewed as the cascaded response of the filter transfer function and an amplifier transfer function. This article examines the phase shift of the filter transfer function itself. While filters are designed primarily for their amplitude response, the phase response can be important in applications such as time delay simulation, cascaded filter stages, and especially process-control loops.

Difference Amplifier Forms Heart of Precision Current Source

Precision current sources are used to provide excitation for RTDs in process-control systems; to measure unknown elements in digital multimeters; and to drive 4 mA to 20 mA current loops, which are widely used to transmit information over long distances. This article shows how a difference amplifier can be used to implement a precision current source.

Understanding Data Converter Errors and Specifications

Perplexed by data converter specifications and how they impact end-system performance? View this webinar and learn how to derive the vital facts from the data sheet.

The Basics of Video Decoders in Supervision and Inspection

Video cameras—which range from inexpensive, low-definition black-and-white closed-circuit television systems to state-of-the-art high-definition digital-video systems—are found in diverse applications including product inspection, traffic monitoring, and real-time face recognition. Dropping unneeded data and passing only the essential parts of the picture can simplify the video system—saving memory and computational cycles.

How to Successfully Apply Low-Dropout Regulators

A low-dropout regulator (LDO) is capable of maintaining a specified output voltage over a wide range of load current and input voltage, down to a very small difference between input and output voltages. This difference, known as the dropout voltage or headroom requirement, can be as low as 80 mV at 2 A.

Measuring Noise of Low-Fixed-Gain Differential Amplifiers

Measuring noise of low-gain differential amplifiers presents a challenge, as their integrated feedback and gain resistors preclude high-gain configurations, and a differential-to-single-ended conversion is needed to match the spectrum analyzer. A second amplifier stage can provide gain and the differential-to-SE conversion, neatly solving both of these problems.

Detecting Human Falls with a 3-Axis Digital Accelerometer

Elderly individuals can suffer accidental falls due to weakness or dizziness. The initial injury can be further aggravated if treatment is not obtained within a short time. MEMS-based fall detectors can sense changes in body position by tracking acceleration, determine when an individual is falling, and issue an alert for assistance. This article describes the use of an ADXL345 three-axis digital accelerometer as a fall detector.

What shall we do with an unused op-amp?

Rarely Asked Questions -- Strange but true stories from the call logs of Analog Devices. View current and archived Rarely Asked Questions at http://www.analog.com/raq

Designing with Switching Regulators in High-Speed A/D Converter

Webinar Series -- View this webinar, recently archived webinars, or webinars by category at www.analog.com/webinars

Automated Calibration Technique Reduces DAC Offset to Less than 1 mV

The AD5360 16-bit, 16-channel DAC is factory trimmed, but an offset of several millivolts can still exist. This idea shows how a simple software algorithm can reduce an unknown offset to less than 1 mV. This technique can be used for factory calibration, or for offset correction at any point in the DAC’s life cycle.

Digital Isolator Simplifies USB Isolation in Medical and Industrial Applications

Despite its low speed and point-to-point nature, RS-232 was tolerated in medical and industrial applications because it was universally available, well supported, and allowed easy implementation of the required isolation. The ADuM4160 digital isolator allows simple, inexpensive isolation of full- and low-speed USB peripherals—including the D+ and D– lines—increasing the usefulness of USB in medical and industrial applications.

Understanding and Optimizing Sampled Data Systems (Part II)

Webinar Series

Next topic: Understanding and Optimizing Sampled Data Systems (Part II)
Wednesday, May 20, 2009, 12:00 PM ET

View this webinar, recently archived webinars, or webinars by category at www.analog.com/webinars