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As the digital transformation permeates deeply across so many industries, it’s easy to forget that some things just work better in analog. And today, the analog world is still alive and thriving. A popular example of that is in the audio component world.
Today’s mass-market audio gear is built largely with digital circuits. Yet, peel back the layers of this platform and one can find a segment that still uses analog components—vacuum tubes, particularly. High-end tube amplifiers are available from eclectic companies such as Audio Research, Fosi, Luxman, Mastersound, Rockville, and others. Even the less esoteric companies like Macintosh and Pyle still offer high-end tube-amplified products.
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Besides audio, analog technology is alive and well in a myriad of other circuits: power supplies, sensors, video equipment, medical instruments, automotive systems, and more.
Why Analog Rather than Digital?
The fact is that analog circuits can offer better outcomes than their digital counterparts for a variety of use cases. In these applications, analog makes certain signals much easier to process, with fewer components, less distortion, and greater accuracy.
Analog also has advantages in instrumentation. Analog handles the measurement and control of physical quantities, such as temperature, pressure, speed, and flow, more accurately than digital. Analog signals are robust and are much less sensitive to interference. And such circuits are typically less complex and less expensive.
Of course, there’s much more to analog. But space limits what can be covered in this discussion. Therefore, it will focus on a common analog component found nearly everywhere—the power module.
Packaging the Power Stage
For power-stage design, engineers have several options. Among them are low-dropout regulators (LDOs), switching regulators, and power modules.
When inductive elements are part of a power circuit, it’s intrinsically analog. Typically, inductors, in whatever form, are external because they’re bulky components and not easily integrated into an IC. This significantly affects the package and can present challenges for circuits that are size constrained.
Designers have been tackling these difficulties for some time. And progress has been made. New packages are being developed that solve some of these issues and make the designer’s job easier.
Today’s power modules come in a variety of configurations. Some are generic, such as TI’s TPSM83100, and others are proprietary, such as the TPSM82816.
While many power modules are mature, designs do evolve. For example, there’s the MagPack. This unique package design eliminates reliance on third-party inductors and offers better thermal conductivity and less electromagnetic interference (EMI) than typical power modules.
However, proprietary comes at a cost. The more mature packages, such as the embedded micro system in package (µSiP), or the leaded quad flat no-leads (QFN), optimize economy. The MagPack, though, is on the cutting edge of power-module technology, and thus is more expensive.
Choices, Choices, Choices
Obviously, many power module choices are available, and the ultimate selection depends on multiple factors: cost, size, performance, package, specifications, etc.
Each design has its advantages and disadvantages. For example, the µSiP offers a power module with a converter IC embedded inside a substrate. However, the inductive and passives are still mounted externally (Fig. 1).
