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Philips UcD Audio Amplifier
Beginning of an Era: If there was one circuit that began the era of mainstream, commercial class-D audio, this is it. According to engineer Bruno Putzeys, “this is literally the first UcD (Universal class-D) prototype I built at Philips.”
Photo: Bruno Putzeys

Editor's note: An audio amplifier module is only part of an audio amplifier, which also needs a power supply, chassis, and assorted connectors, fuses, indicators, and other hardware to function. So a module might be considered an odd choice for a consumer electronics hall of fame. But in this case, several excellent amplifiers were among the first to incorporate Philips's singular UcD class-D module. Selecting one of them would have been a random choice—and when you get right down to it, it's the use of the module that would have made any of them worthy of consideration in the first place.

It's not often that one circuit revolutionizes a huge product category, but the Philips Universal class-D (UcD) module did just that for audio amplifiers. Before the UcD, there had been a few quirky and short-lived commercial class-D amps. But with its stunning combination of small size, light weight, low cost, high efficiency, and remarkable performance, the UcD showed what the technology could do. It helped unleash a wave of design work at other firms that finally pushed class-D amps into the mainstream. Today, it is a virtual certainty that you own at least one class-D unit, in your home, car, smartphone, or smart speaker.

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Digging Into the New QD-OLED TVs

Formerly rival technologies have come together in Samsung displays

5 min read
Television screen displaying closeup of crystals

Sony's A95K televisions incorporate Samsung's new QD-OLED display technology.

Sony
Blue
Televisions and computer monitors with QD-OLED displays are now on store shelves. The image quality is—as expected—impressive, with amazing black levels, wide viewing angles, a broad color gamut, and high brightness. The products include:

All these products use display panels manufactured by Samsung but have their own unique display assembly, operating system, and electronics.

I took apart a 55-inch Samsung S95B to learn just how these new displays are put together (destroying it in the process). I found an extremely thin OLED backplane that generates blue light with an equally thin QD color-converting structure that completes the optical stack. I used a UV light source, a microscope, and a spectrometer to learn a lot about how these displays work.

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