Bringing big sound to small devices: One module revolutionized how we listen - [Resources_Tools]
Brian Santo · IEEE Spectrum · 2019
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, which differed from previous amplifiers by using an intermediate stage in which transistors are rapidly switched on and off, versus directly trying to amplify a signal linearly.