I have a small amplifier IC, rated at about 2.5 - 3W output going into a 3W rated 8 Ohm speaker. The input signal is going through a pot. and than into the amp though a cap and resistor in series, as shown below - only pot. not shown.
I only have 1 speaker connected to pins 1 & 3, the other output is currently not connected.
Normally the amp. uses under 5mA current which is fine, as I turn the pot. the volume goes up as well as the current consumption. When it reaches about 30mA my batteries can't hold the voltage which causes the source device to reset.
Can I limit the current consumption somehow? Perhaps attenuating the input with even larger input resistors. Right now I have 50 Ohms in series with the 100nF caps.
I have this for a datasheet: How is your Chinese?
The NCN pin seems to be doing some limiting or compression to the signal. The datasheet does not give a formula to calculate it however it gives a short table with some examples.
I've tried swapping the input resistor from 50 Ohms to 150 Ohms but that made things much worse - distortion is much higher. I swapped it again to 68K (that's what I had around) and it works very well.
New problem - I can hear a high pitched sound from the speaker, going to use my scope with FFT to find out at what freq. this is at and going to need to filter it out.
Looks like this IC is a clone or similar to this one