I have a small amplifier IC rated at about 2.5 - 3 W output going into a 3 W, 8 Ω speaker. The input signal is going through a pot and then into the amp though a cap and resistor in series, as shown below (pot not shown).
I only have one speaker connected to pins 1 and 3, the other output is currently not connected.
Normally the amp uses under 5 mA, which is fine. As I turn the pot the volume goes up as well as the current consumption. When it reaches about 30 mA 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 Ω in series with the 100 nF caps.
I have this for a datasheet: How is your Chinese?
simulate this circuit – Schematic created using CircuitLab
The NCN pin seems to be doing some limiting or compression to the signal. The datasheet does not show a formula to calculate it, however, it does have a short table with some examples.
I tried swapping the input resistor from 50 Ω to 150 Ω but that made things much worse; distortion is much higher. I swapped it again to 68 kΩ (that's what I had around) and it works very well.
New problem - I can hear a high pitched sound from the speaker. I'm going to use my scope with FFT to find out what frequency this is filter it out.
Looks like this IC is a clone or similar to this one