Lichuang Training Camp Bluetooth Amplifier

Bluetooth digital Class D power
amplifier schematic design description based on TPA3116
1. Stabilized power
supply uses a 24V adapter power supply. The voltage stabilization uses 7805 and 7812. Although the voltage difference is larger, the load current is not large, so the temperature rise is bearable.
In fact, the design is to separate the analog ground and the digital ground, but if it is too troublesome, only GND will be used later. Friends who are not too troublesome can separate it.
 
2. The light strip
adds 10 LEDs of 2-channel LM3915 to make the light strip. In fact, this light strip integrates 10 comparators. If you want the light strip to be more sensitive, just change the voltage dividing resistor of the reference voltage input jio. .
3.
There is nothing to say about the interface and Bluetooth. The Bluetooth and audio interface are left here. I made a switch to switch the sound source. Both inputs can also reverberate, but I haven’t tried it yet. In theory, this is the case. The integrated Bluetooth module is plugged in and used, there’s nothing to say.
4.
The 4.1 front stage of the power amplifier section
has a 2x inverting amplification. The coupling capacitor uses a film capacitor, which has large insulation resistance and is often used for coupling.
4.2
The working mode, gain, and power limit of the TPA3116 in the rear stage are clearly written in the manual. The circuit here is basically copied from the manual.
I calculated the cutoff frequency of the output LC filter by hand to be around 60k, but the simulation was at 80k, which is good. It can also be used, as long as it can filter out the modulated carrier;
the C-RC buffer at the back, the manual says it improves EMI, but I don’t know exactly what it improves, please explain! ! ! ! ! ! !
 
PCB design instructions for
grid grounding, pay attention to the layout and wiring, do not separate the ground, try to connect each GND to each other, and reduce the current loop;
Remember to add a via array at the bottom of TPA3116 and open a window for heat dissipation, especially this GND Try to connect it to the largest main GND to reduce thermal resistance and increase heat dissipation;
as well as the CRC buffer at the back, the manual recommends that it be returned directly to the GND pin of the IC as much as possible;
the power copper entering the power interface should be as small as possible Width;
if there is no trouble limit, the power ground and analog ground can be separated;
physical display instructions
demonstration video