Heavy-duty power supply regulates either voltage, current or power
5/5/1975
Technical Article: By combining switching and series-pass techniques, this high-voltage supply's designer achieved 0.01% regulation at power levels to 100W. |
An introduction to acoustic thermometry
4/21/2011
Technical Article: Use an ultrasonic transducer to measure air temperature in an olive jar. |
Compensate for wiring losses with remote sensing
11/18/2010
Technical Article: By multiplexing a small ac signal on the power wires, you can infer wiring losses. |
Measuring wideband-amplifier settling time
8/12/2010
Technical Article: A novel circuit lets you measure output settling to 0.1% in 2 nsec. |
Precisely measure settling time to 1 ppm
3/4/2010
Technical Article: Intense, extensive, and protracted effort yields a measurement circuit with 20-bit resolution. |
Characterizing noise in high-performance voltage-reference ICs
9/3/2009
Technical Article: Measuring the noise performance of a modern voltage reference requires special measurement techniques.
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Application engineers: serving the customer
6/25/2009
Jim Williams on the changing role of application engineering.
By Paul Rako, Technical Editor
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Diode-turn-on-time-induced failures in switching regulators
1/8/2009
Technical Article: Never have so many had so much trouble with so few terminals. |
High-voltage, low-noise dc/dc converters
8/7/2008
Technical Article: You can make a 1-kV dc/dc converter with only 100 µV of noise. |
Novel measurement circuit eases battery-stack-cell design
By Jim Williams and Mark Thoren, 1/10/2008
Technical Article: A transformer and diode on each cell allows isolated measurement. |
Measure nanoamps to ensure accurate computer clocks
5/10/2007
Video Design Idea: In this EDN Video Design Idea, Jim Williams, staff scientist with Linear Technology, explains why PC clocks are invariably wrong, and how engineers can surmount the extreme measurement challenge involved in solving the problem. |
Designing instrumentation circuitry with rms/dc converters
2/1/2007
Technical Article: RMS converters rectify average results. |
Load-transient-response testing for voltage regulators
9/28/2006
Technical Article: Variations occur in voltage regulators' transient loads; thus, the devices require careful evaluation and testing. |
JFET-based dc/dc converter operates from 300-mV supply
5/25/2006
Design Idea: Use a JFET's self-biasing characteristics to build a dc/dc converter that operates from power sources, such as solar cells, thermopiles, and single-stage fuel cells. |
Minimizing switching-regulator residue in linear-regulator outputs
12/5/2005
Technical Article: Banishing those accursed spikes takes attention to detail and understanding the subtleties. |
Something from nothing
9/15/2005
Tales From The Cube: In the early 1980s, as Linear Technology was just beginning, we had a fundamental problem: products in development but none to sell. But, we wanted prospective customers to know our name and what we were up to. Our public-relations company glibly urged "controlling the press" and "getting our message out" but offered little real substance. |
1-Hz to 100-MHz VFC features 160-dB dynamic range
9/1/2005
Design Idea: Transform voltage to current over wide frequency, amplitude. |
Dynamic-load circuit determines a battery's internal resistance
3/31/2005
Design Idea: Meet the challenge of measuring a battery's internal parameters with a nonstatic load approach. |
Quartz crystal-based remote thermometer features direct Celsius readout
3/17/2005
Design Idea: Although quartz crystals have served as temperature sensors, designers haven't taken advantage of the technology because few manufacturers offer the sensors as standard products. |
Simple nanosecond-width pulse generator provides high performance
11/11/2004
Design Idea: If you need to produce extremely fast pulses in response to an input and trigger, such as for sampling applications, the predictably programmable short-time-interval generator has broad uses. |
Simple circuitry for cellular-telephone/camera-flash illumination
By Jim Williams and Albert Wu, 5/27/2004
Technical Article: Successfully implementing flash lamps involves understanding numerous practical considerations. |
The taming of the slew
9/25/2003
Technical Article: Deriving a slew-rate-measurement approach requires understanding slew rate's relationship to amplifier dynamics. |
A clock for all reasons, part 2: Monolithic oscillator invigorates instrumentation applications
7/10/2003
Technical Article: Part 1 of this series presented a variety of circuits that use a monolithic oscillator in various applications. Part 2 continues with more examples: chopped amplifiers, sine-wave generators, an interval generator, and an ADC. |
A clock for all reasons, part 1: Monolithic oscillator invigorates instrumentation applications
6/26/2003
Technical Article: In addition to their common role as clock sources in digital systems, oscillators play an important role in instrumentation applications. A simple and tunable oscillator boosts the performance of a range of circuits. Part 1 of this series presents an RTD digitizer, thermistor-to-frequency converters, and relative-humidity digitizers. |
Bias-voltage and current-sense circuits make avalanche photodiodes work
3/6/2003
Technical Article: Feeding and reading an avalanche photodiode takes a high degree of circuit sophistication. |
Bootstrapping allows single-rail op amp to provide 0V output
2/6/2003
Design Idea: Many single-supply-powered applications require amplifier-output swings within 1 mV—or even submillivolts—of ground. |
Current sources for fiber-optic lasers: a compendium of pleasant current events
8/22/2002
Technical Article: It takes an aura of thoughtful caution to design a laser current source. A range of circuits that use linear and switched-mode techniques shows how. |
Controlling the temperature of fiber-optic lasers
7/5/2001
Technical Article: Thermoelectric-cooler-based temperature controllers have some unusual requirements. They account for circuit- and thermal-design characteristics to provide climatic pampering for temperamental lasers. |
Minimizing thermocouples maintains 20-bit DAC precision
5/3/2001
Technical Article: Undesirable and unintended thermocouples are the primary sources of error in low-drift circuits. Attention to layout and other construction details is the only way to tackle the problem. |
Measurement techniques help hit the 1-ppm mark
4/26/2001
Technical Article: Part 2 of this series on the design of a 20-bit DAC discusses the all-important techniques for testing the performance-linearity, settling time, and noise-at such minuscule data levels. See Part 3 in the next issue. |
20-bit DAC demonstrates the art of digitizing 1 ppm, part 1: exploring design options
4/12/2001
Technical Article: For the price of a San Francisco dinner, you can put standards-lab performance on a circuit board. Part 1 of this three-part article chronicles a 1-ppm DAC and its various design options, part 2 in the next issue presents verification techniques, and part 3 discusses the handling of parasitic effects. |
Thank you, Bill Hewlett
2/1/2001
Jim Williams remembers Bill Hewlett—co-founder of Hewlett-Packard. |
Switching-regulator supply provides low-noise biasing for varactor diodes
By Jim Williams and David Beebe, 11/9/2000
Technical Article: Low-voltage systems often need a locally generated high voltage. Even for an application as noise-sensitive as varactor-diode biasing, a carefully planned switching-regulator-based design and layout can provide the necessary bias voltage. |
Pulse generator has low top-side aberrations
5/25/2000
Technical Article: Impulse-response and rise-time testing often require a fast-rise-time source with a high degree of pulse purity. These parameters are difficult to achieve simultaneously, particularly at subnanosecond speeds. |
Understanding and selecting rms voltmeters
By Jim Williams and Todd Owen, 5/11/2000
Technical Article: Failing to verify ac-voltmeter accuracy before conducting rms-noise measurements may cause highly misleading results. |
Exacting noise test ensures low-noise performance of low-dropout regulators
By Jim Williams and Todd Owen, 5/11/2000
Technical Article: Although verifying that a low-dropout regulator meets its dropout specification is straightforward, verifying its noise performance proves more difficult. You have to pay careful attention to the test setup, including the voltmeter you use. |
A svelte beast cuts high voltage down to size
By Jim Williams and J Phillips and G Vaughn, 11/24/1999
Technical Article: Piezoceramic transformers have many features, including small form factor, that make them inherently well-suited to CCFL-backlight inverters. |
Measuring precision-amplifier settling time
10/28/1999
Technical Article: Obtaining a reliable settling-time measurement is difficult and requires a careful approach and an experimental technique. You can use new circuits to test the 30-nsec settling time of a precision wideband amplifier. |
Measuring 16-bit settling times: the art of timely accuracy
11/19/1998
Technical Article: Accurately measuring the settling time of a 16-bit DAC and its output amplifier is an art form. One measurement technique borrows from the design of a classic sampling oscilloscope and provides reliable results. Three other measurement approaches produce results that closely agree with each other. |
Fast comparators find their niche in linear applications
9/11/1998
Technical Article: Comparators don’t “just compare” in the same way that op amps don’t “just amplify.” A collection of application circuits demonstrates just how flexible and useful a high-speed comparator can be. |
Layout and probing techniques ensure low-noise performance
2/2/1998
Technical Article: A cavalier attitude regarding a low-noise design is a direct route to disappointment. Achieving and maintaining the low-noise potential requires judicious layout, probing, and connection techniques. |
Chopped amplifier exacts only 5 µA
5/22/1997
Design Idea: The chopped amplifier in Figure 1 combines low supply current of 5.5 µA with high accuracy. The offset voltage is 5 µV with a drift of 0.05 µV/°C. The gain exceeds 108, which affords high accuracy, even at large closed-loop gains. |
0.02% V/F converter consumes only 26 µA
7/4/1996
Design Idea: Figure 1 shows a voltage-to-frequency (V/F) converter that produces a 0- to 10-kHz output for an input range of 0 to 5V. Linearity of the converter is 0.02%, and gain drift is 60 ppm/8C. The maximum current consumption is only 26 µA, 100 times lower than currently available units. |
Measurements on CCFL-driver circuits pose tricky problems
5/9/1996
Technical Article: Obtaining reliable efficiency data for CCFL circuits presents difficult measurement problems. The accuracy required in the high-frequency ac measurements is uncomfortably close to the state of the art. |
Avoid pitfalls in dimming and shutting down CCFL backlighting for LCDs
3/14/1996
Technical Article: Providing high-efficiency backlighting for LCDs is easier than it used to be thanks to ICs tailored for the purpose, but several elements of the circuit design still require care. Dimming and shutdown are two of them. |
Tripping the light fantastic: a case study in circuit design
3/16/1995
Technical Article: Good circuit design involves a mixture of imagination, experimentation, and a willingness to borrow from the lore of innovators who preceded us. |
Try fixing it yourself
2/2/1995
Technical Article: Drag out some of that obsolete electronic equipment collecting dust in storage. Your next cutting-edge innovation may come from tinkering with a relic of the past. |
Pulse generator verifies test setups
5/26/1994
Design Idea: Verifying the rise-time limit of wideband test-equipment setups is a difficult task. In particular, you must often know the "end-to-end" rise time of an oscilloscope/probe combination to ensure measurement integrity. |
Synchronized regulator produces coherent noise
3/17/1994
Design Idea: By using a gated-oscillator architecture instead of a clocked-PWM one, gated-oscillator-type switching regulators permit high efficiency over extended ranges of output current. This architecture eliminates the housekeeping currents associated with the continuous operation of fixed-frequency designs. |
Techniques illuminate backlit LCDs with high efficiency
1/6/1994
Technical Article: Getting a backlight LCD lamp to turn on is just the first step in the design process. Achieving and maintaining high efficiency requires attention to both circuit-design and physical-layout details. |
Jim Williams was a staff scientist at 
