As I was trying to refurbish my Sony STR-434BS, I choose to install a brand new audio amplifier IC, specifically the TDA8954 as main chip for it's power deliver (around 100 [W] in stereo mode) and high-efficiency (doesn't need to be much, yet it's better than a 60% efficiency). Looking at the datasheet, there is a proposed schematic, which fulfill most of my needs. My question is: there are two input ports, each with a negative and positive terminal (IN1 and IN2). I have a RCA cable input as a proposed input, therefore I must design a differential signal input in this case? Bellow is the proposed schematics on the IC datasheet.
While the IC allows you to use differential input signals, it doesn't mean you have to. It's perfectly valid to just tie one side of a differential input to ground and drive the other side with a single-ended signal. Be careful with your current return paths, though, you don't want to have high power circuitry attached to the same ground as your sensitive low power signals.