I'm working with the TDA7266D dual bridge audio amp.
The datasheet indicates that the device can operate with VCC between 3.5V and 12V. I'm running nominally at 5V and the output signal is fine. What I would like to do is kick up the voltage to around 9V to get a bigger output swing for the speaker. However as I increase the voltage the output signal rises, but diminishes and flattens. Looking at pin 7 IN1 (at the IC pin) I can see that the bias on the input doesn't change with the increase in voltage. Is VREF fixed for this part? Is that the reason the output signal is getting quashed? Has anyone had success with running this part with higher voltages?
The circuit I have is identical to the circuit shown on page one of the datasheet except I'm only driving one speaker with OUT1.