A Note From the Editor

Welcome to the August issue of Analog Dialogue.

About a year ago, Brad Brannon approached me with the idea for an article looking back at the past 100 years of the superhet receiver. I thought, what a brilliant idea to show the development of radio technology from its beginning, to the super heterodyne receivers, and nowadays to software-defined radio (SDR). Currently Brad is responsible for system engineering for 4G and 5G receive architectures, so he’s well-suited to write this history. As for his own history, Brad has worked as an engineer at Analog Devices for 34 years.

While I’m on the subject of radio, I was listening to my noise free DAB+ radio (brass band, of course) streaming from the internet, and my good friend and colleague Dave Kruh came to mind. Dave collects old radios. His oldest is a floor model Sparton 600 from 1930. They’re bulky, noisy, and mainly come in wooden cases, but they have a lot of charm. The old technology has its own character with tubes, large trim capacitors, many mechanical parts, AM and FM antennas, and the warm-up phase and clicking noises they make. There is a lot of history there as well, and Dave has written about topics ranging from reassembling old radios to the changing standards of state of the art. Unfortunately, the old radios my grandfather owned have been recycled. I’m looking for one so I can keep a bit history in my house.

Back to articles … our next is a collection of unusual applications for a refulator. What’s a refulator? It’s a high precision reference with two linear regulators in one package. As for its applications, here are a few appetizers: a precision voltage source and a precision current source; a multivibrator; a small loudspeaker driver; a strain gage; and many more. This article comes to us courtesy of Mike Anderson. Mike is a senior IC design engineer with Analog Devices, where he works on signal conditioning products, such as precision references and amplifiers.

If you work in the automotive or industrial world, you understand the demand for cool running power supplies that fit tight spaces and meet low EMI standards. Joey Yurgelon, Jesus Rosales, and Mark Marosek introduce you to a switching regulator family that can deliver 60 V/2 A, 60 V/4 A, and 100 V/2 A. The family accepts a voltage input down to 2.8 V (max 60 V), which is important for the cold-cranking conditions many automobiles have to contend with. The regulators combine high power delivery with small packages while meeting stringent thermal and EMI requirements. Mark, Joey, and Jesus work together in the Power by Linear Group, concentrating mainly on SEPIC converters.

Frederik Dostal brings us an interesting topic for this month’s RAQ. You all know the importance of twisted pair cables and the necessity to drill them to minimize the parasitic line inductors. Have you ever considered what happens when you drill the power supply cables in your lab while powering an eval board or PCB? I must admit—I have not. That might be because I grew up with linear regulated power supplies. I am sure with today’s lab equipment you will get switched power supplies and the distortion could get transferred to the PCB you are powering. Frederik has a simple and interesting approach to it.

In this month’s StudentZone, we take a look at parallel LC resonance. This article continues the dynamic series we had during the past month on phase, swinging, and transient responses. I hope you’re still having fun with the ADALM1000. Our hosts, Doug Mercer and Antoniu Miclaus, will help us to understand more and more about resistors, capacitors, and coils. 

And as we have for over 50 years, we invite you to be part of the “dialogue” in Analog Dialogue. You can get in touch through our blogFacebook page, or email. Let us know how we’re doing and what you’d like to see from us in the coming months.