Input Voltage LM8560
Look at the application diagram in the datasheet and notice that there's a 100 kohm resistor between the transformer and pin 25 of the LM5860:

Do note that this IC and its circuit is a bit unconventional, VSS = grounded which is normal but VDD is a negative supply voltage which is uncommon these days. This was more common in the 1970s and early 1980s though. This LM5860 is made in &quot;P-channel ED MOS LSI&quot; technology which is ancient so that could explain this.
In this circuit the center tap of the transformer is grounded so the voltage going to the 50/60 Hz input will not fit in the -15 V to +0.3 V. But it doesn't matter! The IC very likely has internal clamping diodes which are needed for ESD protection, these diodes can operate in forward mode as long as the current is limited (to for example less than 1 mA, that's just my educated guess).
This is where that 100 kohm resistor comes in, even if the transformer delivers a voltage that is larger than -15 V to + 0.3 V, the resistor will limit the current to a safe level so no damage is done.
It is not a very &quot;elegant&quot; way to limit the input voltage to pin but it works. A more elegant way would be to something like this circuit:



simulate this circuit &ndash; Schematic created using CircuitLab
Where the 1 k resistor and the 5.6 V zener diode limit the voltage to -5.6 V to + 0.7 V which exceeds the + 0.3 V maximum but again there is a 100 k ohm resistor to limit the current so nothing bad can happen.
It is unclear to me what the detection level of the 50/60 Hz input is, maybe it needs a higher voltage than -5.6 V, you could use a 12 V zener diode in that case. But first try the solution using only a 100 k resistor as that will probably work well enough.