tda7297 pulsing output

[abador]

I plugged in my module that I got off of amazon with this chip installed. An onboard LED also flashes which goes to pin3 which should be the vcc. I am providing the circuit with the maximum 18 volts. Could the ic be bad or could I be overloading the internal overload protection somehow? I have another ic I can put in the circuit as well as everything else to make the circuit function so I can easily replace bad parts.

[audioguru]

Since you bought it from Amazon then maybe the IC is a fake or maybe the circuit is designed wrong. Please provide a link to it.
The output pulses? When it is playing loudly? Does the heatsink get hot? What impedance are the speakers? What is the maximum continuous current from the 18V power supply?

If two 8 ohm speakers are playing at 14W each with a little clipping distortion then the power supply must provide 18VDC at 2.5A (45W).

[abador]

This is the link; http://www.amazon.com/gp/product/B00K67WI9I/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

It was a cheep one from china so I wouldn't be surprised if there was something wrong with it. The pulsation is in the form of a buzz in the speakers, it won't play music. The speakers are 8 ohms. I did not notice the heat sink getting hot and I did have it plugged in for several minutes. The pulses are the same volume despite where I had the volume knob. The output amperes of the power supply is 1 amp so I guess I made a mistake when calculating the requirements when I bought it, I thought I actually had some power to spare but I didn't think about how it would be providing the same amount of power to both speakers. I do have a 12 volt power supply rated for 5 amps so I don't ruin the one that I bought. Will 5 amps be enough?

[Guest elboa8]

The specs for this say a nominal 12 V @ 2 A. So yes your 12 V 5 A is fine. Looking at the only comment ( 1 star ) I would check the soldering etc. carefully. Good luck.