Readers offer analog guru Bob Pease their own anecdotes about working on sensor arrays, noise rejection, and driving one-handed.

Design guru Bob Pease exchanges some correspondence with readers about his August 13 column, "What's All This Little Guy Stuff, Anyhow?"

Analog design guru Bob Pease tackles the challenges of driving his 1969 Beetle with one hand, as he takes us on a couple of test drives.

Design guru Bob Pease answers reader questions about how to build a variable-frequency power supply and 2N706 circuit failures.

In many industrial, scientific, and medical (ISM) band wireless applications, receiver sensitivity greatly limits the range and reliability of the radio link. One way to get greater sensitivity is to add more gain. But that works well only if the noise figure is good enough. The Maxim Integrated Products MAX2634 solves that problem for some applications. This low-noise amplifier (LNA) for the 315- and 433-MHz ISM bands improves receiver sensitivity and offers an ultra-low 1.25-dB noise figure.

Back about 1965, when I was at Philbrick, we were doing some business with Amelco Semiconductor. I had designed a good hybrid op amp (the Q85AH) and Amelco was trying to build it, but they had some test problems, and some yield problems... so I flew out to help find and solve their problems. The first morning, I put in an hour looking at their test setup. Nothing showed up right away. So we went over to their cafeteria for a cup of coffee. Several engineers ...

What is the most critical performance characteristic for clock chips used with high-performance data converters? The clock signal’s phase noise (or jitter— the time-domain representation of phase noise) is the most critical spec. But also, pay attention to the band over which the jitter has been integrated. Phase noise limits signal-to-noise ratio (SNR). For converter applications, broadband RMS additive jitter is a good...

A good general view of field-oriented control (FOC) can be found in Texas Instruments’ 1998 white paper, “Field Orientated Control of 3-Phase AC Motors”, which can be downloaded for free. For a more recent treatment, though its references go back at least as far as 1980, readers can check out “A Seamless Whole Speed Range Control of Interior PM Synchronous Machine without Position Transducer” by Filka, Balazovic, and...

Regardless of their primary field, sooner or later, most designers have to deal with motor controls. Broadly speaking, there are two methods to incorporating these components in your design. First, designers can start with one of the many choices of microcontrollers that are available and then address the challenges of making the control do what they want. Or second, designers can start at the other end and examine the interaction between motors and...

Addressing lower-cost opticalimage stabilization (OIS) as a major goal, InvenSense Inc. has unveiled the first digital dual-axis pitch and roll (X and Y) gyroscope for camera phones and digital still cameras. Its nextgeneration IDG-2000 family offers the smallest such devices on the market, housed in a 4- by 4- by 0.9-mm quad flat no-lead (QFN) package (Fig. 1). The chip is designed for OIS...

While creating an infrared beam intrusion detector system, the need for a beam-focusing method became evident. Parts from a modified Genie garage door Safe-T-Beam system, purchased at the local home improvement store, proved to be perfectly suited to the application. The main reason for choosing the Genie unit is that the IR transmitter and receiver housings each contain a plastic lens inside a short plastic tube molded into the housing. The tube and lens...

Most switching power-supply controllers provide non-latching fault protection. Satisfying a requirement for a latchoff response to a fault often requires the addition of excessive and redundant circuitry. For power-supply controllers with an external soft-start pin, however, a simple circuit can be added to convert its non-latching fault protection into one with latched protection. For typical controllers, the startup sequence begins by charging the VDD...

An earlier Idea for Design described LED “candles” that you could blow out just like normal birthday candles (“Electronic Birthday Candles ‘Blow Out’ One At A Time”). A thermistor and heating resistor combination detected air blown over the thermistor. The control circuit incorporated an 8-bit shift register, a quad op amp, and driver transistors, allowing up to eight ...

When Electronic Design asked me to write about my Idea for Design, first seen in this year’s August 13 issue, it seemed a simple enough task. We’re all familiar with design. Most of us do it in some form or another almost every day. But, ideas? We all have them, but where do they come from? And what is the essence of a good idea? Simplicity? Elegance? Performance, novelty, creativity? Thomas Edison once said that genius is 1% inspiration and 99% perspiration....

BY MAKING A RELATIVELY simple change in a differential amplifier stage, designers can significantly reduce the sensitivity to digital switching noise. In mixed-signal ICs, digital switching noise couples through the common substrate into analog circuits, degrading their performance. In CMOS circuits, most substrate noise couples into NMOS transistors through backgate modulation. That is, the substrate acts as a second gate with a transconductance gain...