The PSG chip competed with the DCSG (Digital Complex Sound Generator) chip family (SN76489, SN94624, TMS9919) by Texas Instruments. The DCSG has similar sounding features except that it does not have any envelope control and that its noise generator has its own dedicated channel.
Known clones of the PSG are the Toshiba T7766A, Winbond WF19054, JFC 95101 and File KC89C72are clones of the PSG. [https://wiki.agiri.ninja/sound_chip_clones:index Source]
Yamaha produced the SSG (Software-controlled Sound Generator) chip family (YM2149F, YM3439, YMZ294, YMZ284, YMZ285) which is a quasi-clone of the PSG. This chip equips the [[Atari ST]]. The main difference is that the envelope counter on the PSG has 16 steps. On the SSG it has twice the steps, happening twice as fast.