TDA7498 – 200W class D audio amplifier

Many years ago, it is not easy to build a powerful audio amplifier. You will need big power transistors with massive heavy heatsinks plus a heavy transformer too. It will also require a lot of efforts to build it, from drilling the heatsinks and connecting those wires. It is a very tiring task. Today a 200W amplifier can be as small as your mobile phone. Thanks to the evolution of Class D audio amplifiers. Smaller and more efficient amplifiers are now possible.

And since I don’t have enough time to build a PCB and other stuff, I just ordered from lazada It looks good and promising.

I ordered this for only Php898, all assembled and tested. It is a very good deal, not to mention cheap!

Schematic

There is no available schematic of this board but it should be almost the same as stated on the TDA7498 datasheet.

Performance

I haven’t tested it at full power because I don’t have yet a power supply capable of delivering 240W power. But as far as I can tell, the performance is good. I can’t hear any hum and the sound is clear. I will update this post once I got a capable power supply to test it at full power.

Design Issues

The design of this board is not perfect and there is still a room for improvement. Here are what I found out:

• Capacitors are rated 35V and the datasheet specifies 100W output power at 36V input. This means that you can never reach the peak power of 100W because you can’t supply it with 36V because of the capacitors.
• The Heatsink has no screws meaning it is attached via special kind of paste. This means that this board it not recommended for use for your car. The heatsink might detached when it experience vibrations from a car.

12V Operation

This amplifier actually works on 12V supply so you can use it on your car. But the main problem is that at 12V power supply, it really can’t deliver its maximum power. To be able to enjoy its maximum power at 12V operation, you will need a boost converter. Boost converter are use to increase a DC voltage to certain level. Just make sure that the boost converter you will use have maximum output current of at least 8A and output voltage not more than 30V but not less than 24V.

Below is the image of a boost converter that you can use. The output voltage is adjustable so be sure to adjust it first before connecting to the amplifier. VIN+ will be connected to car battery and VOUT will be connected to the Amplifiers power supply input.

 




Read Also – 50W Car Amplifier Circuit – with PCB design file you can download for free. 🙂