I decided to make pretty simple but powerful enough audio amplifier. For this, I’ve chosen quad-bridge car audio amplifier IC – TDA7384, which has four input and four output channels with power capability 4x35W(4Î©).
If connected to a car battery where the operating voltage is about 13.2V, then each channel can give 22W what is more than enough for me. This amplifier I probably will use to test audio processor TDA7313, which is still in the development phase. I didn’t find much information about this chip on the internet, so I decided to build it and try on my own.
As datasheets of TDA,7384 says, it is low distortion, low output noise, low external component count. Also has Stand-By function and Mute function. It has several protections like from output short circuit to GND. or to Vs, capable of handling very inductive loads, thermal limiter, load dump voltage. TDA7384 is an AB power amplifier cased in flexiwatt25 (eagle library is included in project archive) package which is designed for high-end car radio applications. It allows the rail to rail output voltage swing with no need of bootstrap capacitors.
(click to enlarge)
I have followed the schematic in datasheet when building a circuit. In the datasheet, you may also find PCB layout, but it is two-layered and didn’t fit the box I’ve chosen. So I have made single-sided PCB 50X100mm.
As I put pins on PCB for ST-BY and Mute but I not using them, I connected these pins to VCC like it is shown in PCB view. According to the datasheet, St-By and Mute turn off amplifier if the signal in the input is lower than 3.5V. So it is recommended to connect these pins to Vcc if not used.
Maximum power dissipation of the chip is 80W(Tcase=70ºC), so it can handle four channels working at the power of 20W each. But of course, chip in a box doesn’t have proper ventilation, so I’ve put a radiator to ensure that the amplifier effectively dissipates heats. I didn’t try to load amplifier to the maximum to see if it doesn’t heat up too much. But at a reasonable sound level, it stays warm what is normal.
Dont forget to put thermal paste between chip and radiator to ensure lower thermal resistance. And here we go -“ brand new power amplifier ready to go:
When I will try it more, I will write comments on it.
Project files are here: TDA7384 Eagle Files.