Analog Diablog is the place to comment on the articles found in Analog Dialogue (or those that you'd like to see). It can also be used as a discussion forum on products, applications, technology, and techniques for analog, digital, and mixed-signal processing using Analog Devices components.
Touch-screen displays are replacing mechanical buttons in smart phones, MP3 players, navigation systems, laptop computers, and other devices. First generation devices suffered from low accuracy, false detection, and high power consumption. New devices--which offer improved accuracy, lower power consumption, and result filtering--can also sense temperature, supply voltage, and touch pressure.
PIN diodes, which sandwich a lightly doped intrinsic region between heavily doped P and N regions, are used extensively in RF and microwave applications. PIN diode drivers--which provide a controlled forward bias current and reverse bias voltage--use discrete designs or specialized ICs. As an alternative, widely available op amps can be used. Op amps in this class feature wide bandwidth, high slew rate, and enough steady-state current to drive PIN diodes.
Designers of dc-to-dc converters are faced with an overwhelming number of options for power management ICs. Finding the best combination of features, performance, integration level, and price can be difficult enough, and the actual design work can be daunting. ADIsimPower™ simplifies the IC selection process and provides the information required to build an optimized dc-to-dc converter.
When using clock distribution devices or clock fanout buffers to clock ADCs and DACs, two main sources of signal degradation need to be dealt with: PCB traces behave like low-pass filters, attenuating clock signals and distorting clock edges as they travel along the trace; and reflections can cause undershoot and overshoot, severely degrading the signal and the overall clock performance.
A diff-amp in a feedback loop with an inverting op amp is useful for measuring differential signals up to 500 V. This circuit also rejects large common-mode voltages, and allows the differential gain to be set by a ratio of resistors, enabling the user to select the level of attenuation.
Phase-locked loops are used to provide the local-oscillator function in radio receivers and transmitters; for clock distribution and noise reduction, and as the clock source for high-sampling-rate analog-to-digital converters. This article considers the basics of PLLs, examines the current state-of-the-art in PLL design, discusses pros and cons of typical architectures, and introduces some alternatives to high-voltage VCOs.
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.
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.
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.
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.
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.
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.
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.
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.
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.
