Table of Contents
TDA7294 TDA7293, Audio Power Amplifier, board with SMD components using IC TDA7294 or TDA7293, or TDA7295, or TDA729 and other Equivalent ICs. This project features a compact audio power amplifier using the integrated circuit TDA7294, with SMD components for assembly. It is also compatible with ICs TDA7293, TDA7295, and TDA7296, making it ideal for active speakers or as a substitute for damaged boards.
Schematic TDA7294 TDA7293 audio amplifier SMD PCB
Specifications of Integrated Circuits
| IC | Recommended Voltage 4Ω | Recommended Voltage 8Ω | Max power (W) |
|---|---|---|---|
| TDA7293 | ±35VDC | ±40VDC | 120W |
| TDA7294 | ±30VDC | ±35VDC | 100W |
| TDA7295 | ±25VDC | ±30V | 80W |
| TDA7296 | ±22V DC | ±28V | 60W |
Project Features
- PCB Dimensions: Only 33 × 50 mm, ideal for small spaces.
- SMD Technology: Components mounted directly on the surface of the plate, ensuring greater compactness and efficiency.
- Simple Configuration: Requires few external components, facilitating assembly.
- Applications: Audio amplification in active speakers, home theaters, background sound systems, or replacement of defective amplifiers.
Operation of the Circuit
The TDA7294 is a class AB amplifier with output based on MOSFET transistors, reducing distortion due to common crossover in bipolar amplifiers. It offers:
- Mute and Standby Mode: External control for muting or putting the circuit on standby.
- Symmetrical Power Supply: Requires a symmetrical power source (e.g. ±24V to ±35V).
- High Sound Quality: Low total harmonic distortion (THD) and wide frequency response (20 Hz to 20 kHz).
Assembly and Care
- Use appropriate heat sinks to prevent overheating.
- It is necessary to isolate the heat sink from the integrated circuit’s metal.
- Make sure the symmetrical power supply provides enough current (minimum of 2A).
Advantages of Using SMD Components:
- Reduction in PCB size.
- Improved thermal and electrical performance.
- Automated process that reduces assembly errors.
This project combines power, sound quality, and compactness, being a practical and efficient solution for various audio applications. For the TDA7294 amplifier, the choice of power supply is crucial to ensure optimal performance, reliability, and safety. Here are the recommendations based on the specifications of the integrated circuit and common practices:
Power Supply Requirements
- Power Supply Voltage:
- The TDA7294 operates with a symmetrical power supply, meaning positive and negative voltages in relation to ground. The recommended range is ±10V to ±40V, with ±35V being the ideal voltage to maximize power and efficiency without compromising safety.
- The absolute maximum voltage is ±50V without signal, but operating close to that limit can cause overheating or failures.
- Current:
- The TDA7294 may require up to 10A of peak current in low impedance loads (4Ω). For continuous use, it is recommended to have a power supply capable of providing at least 3A per channel.
- Regulation:
- A well-regulated source is essential to avoid voltage fluctuations that affect the amplifier’s performance.
Diverse Applications
- It can be used in a wide range of systems, such as:
- Home theaters.
- Amplifiers for musical instruments (guitars and violins).
- Professional audio distribution systems.
- Replacement or upgrade in active loudspeakers.
- Replace defective amplifier board.
BOM
Last update: 01/19/2025 13:36
| Parts | Value | Description | Quantity |
|---|---|---|---|
| Resistors | |||
| R1 | 30K (303) | R0603 — Resistor SMD | 1 |
| R2, R5 | 22K (223) | R0603 — Resistor SMD | 2 |
| R3 | 20K (203) | R0603 — Resistor SMD | 1 |
| R4 | 10K (103) | R0603 — Resistor SMD | 1 |
| R6 | 680 (681) | R0603 — Resistor SMD | 1 |
| R7 | 10Ω (10R) | R1206 — Resistor SMD | 1 |
| R8 | 1K (103) | R0603 — Resistor SMD | 1 |
| Capacitors | |||
| C1 | 1uF | Film capacitor | 1 |
| C2, C3, C9, C10, C12, C13 | 22uF/63V | Electrolytic capacitor SMD 6.3×6.6 | 6 |
| C6, C7, C8 | 100nF/100V | C0805 — SMD Capacitor | 3 |
| C11 | 100P | C0603 — SMD Capacitor | 1 |
| Semiconductors | |||
| D1 | 1N4148 | Switching diode SOD-123 | 1 |
| IC1 | TDA7293, ou TDA7294, ou TDA7295, ou TDA7296 | MULTIWATT15V DMOS amplifier with mute and standby | 1 |
| Miscellaneous | |||
| CN1 | IN — Audio input | XH connector 2.54 mm 2 pins | 1 |
| J1 | POWER — Power supply | Terminal block 3 pin (Kf301, KR301) 5.08 mm | 1 |
| J2 | OUT — Audio input | Terminal block 2 pin (Kf301, KR301) 5.08 mm | 1 |
| SJ1 | Jumper SMD | Select between TDA7293 and the other chips. | 1 |
Download files, links, and notes
Download PCB in Gerber + BOM + Centroid file + PDF + PNG
Hi Toni!
My name is Manu – I’m running a project called OTTOsonics in Austria. We offer affordable and open solutions for multichannel audio systems, develope speakers and amplifiers, organize concerts and try to encourage people all over the world to do the same. In fct there is a partner project starting in Sao Paolo right now…
I have been using tda7294 ICs for 24 channel amps and just found your SMD design and want to get a few of those to compare. I’m really happy with the sound quality but I also want to look into Class D amps for mobile battery powered applications.
For the amps that I’m building I’m using a input filter PCB that does the ‘unbalancing’ and a HPF via an opamp. After soldering hundreds of those I would like to redesign to SMD components them have them assembled. Could you image helping me with this?
Thanks!
All the best
manu
Hi Manu,
It’s fantastic to hear about the work you’re doing with OTTOsonics – it sounds like you’re making a significant impact in the audio community, especially with your partner project in Sao Paolo!
In regards to your question, I would be more than happy to help you with your transition to SMD components. I agree, they can be a great way to streamline the production process, especially when you are dealing with a large quantity. The TDA7294 SMD design has been working well for me, and I think it might be a good fit for your multichannel amps.
Class D amps are indeed an excellent choice for mobile battery powered applications due to their high efficiency. I can help guide you in the right direction for this as well.
Let’s discuss more about your project requirements and see how we can optimize your designs for SMD components. Feel free to send over any specific questions or concerns you have, and we’ll tackle them together.
Best,
Toni