TDA7294 amplifier circuit diagram PCB

TDA7294 amplifier circuit diagram PCB

TDA7294 amplifier circuit diagram PCB, project of circuit potent audio amplifier with TDA7294. Super Amplifier with tda7294 from St microelectronics, it is possible to get power up to 100W in a single integrated circuit, for a stereo unit use two just like this one. This circuit is based on the manufacturer’s datasheet on the typical application of using the tda7294. The amplifier is ready to work with strong signal sources, if necessary use a preamplifier in the form of an opamp.

The TDA7294 is a monolithic integrated circuit in Multiwatt15 package, intended for use as audio class AB amplifier in Hi-Fi field applications (Home Stereo, self powered loudspeakers, Topclass TV). Thanks to the wide voltage range and to the high out current capability it is able to supply the highest power into both 4Ω and 8Ω loads even in presence of poor supply regulation, with high Supply Voltage Rejection. The built in muting function with turn on delay simplifies the remote operation avoiding switching on-off noises.

All features

  • Thermal shutdown
  • Short circuit protection
  • Very low distortion
  • No boucherot cells
  • Very high operating voltage range (±40v)
  • High output power (up to 100w music power)
  • DMOS power stage
  • No switch on/off noise
  • Very low noise
  • Muting/stand-by functions

This category of IC circuit is ideal for surround sound systems. Because it is very compact, you can use an independent amplifier for each of the speakers. In this way, you can share the power supply, dimensioned of course to support all the connected amplifiers. Then you can get a kick out of that neighbor who bought a 1200W PMPO home theater, and say it is a great power, but when you check the real power of the equipment, it doesn’t even reach 10W RMS per channel. Can you imagine an active speaker system with 80W? If it were to go through the marketing department, which defines the PMPO power, your system would give… let me see… compared to the example above… some “1500 W PMPO”. It’s a joke what they are doing with the power of the equipment.

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To make your sound system, you will only need the signal source. Well, the amplifier can be perfectly fine here. The subwoofer needs a little more power, so in the datasheet you will find an example of a bridge assembly to increase the power. Below is the schematic, the printed circuit board, and details of the assembly. Good luck.

Good luck.

Basic application for Ic tda7294 amplifier schematic (updated 07/2021)

Schematic diagram circuit power amplifier tda7294

Schematic Diagram Circuit Power Amplifier Tda7294
Schematic Diagram Circuit Power Amplifier Tda7294


Suggestion of Printed circuit board (PCB) amplifier TDA7294

Suggestion Of Printed Circuit Board (Pcb) Amplifier Tda7294
Tda7294 Amplifier Pcb Layout
Suggestion Of Printed Circuit Board (Pcb) Amplifier Tda7294
Tda7294 Amplifier Pcb Layout

Suggested printed circuit board for circuit assembly, in full size of the assembly. (Updated 10/2010) Download the PCB and PDF files

Tda7294 Pinout Datasheet
Tda7294 Pinout Datasheet

Some information about the circuit

The tracks in red are jumpers, you must connect a piece of wire between the 2 points. If you use a double-sided board, you do not need the jumpers.
In CN2 we should connect the input signal, connected to capacitor C1 of 1µF, which can be used in various dimensions. Capacitor C1 besides blocking the DC components also forms a high-pass RC filter with R4 of 22K, a resistor that also determines the input impedance of the amplifier. With the selected components in the circuit we have a cutoff at about 7Hz, with a 3.3µF capacitor we have a cutoff at 2Hz. The 220pF capacitor will filter RF signals.

At connector CN1 we connect the power supply that must be symmetrical ± volts from ± 25 to ± 35 volts. Pin 1 connects the +VCC of the source, pin 2 connects the Ground (GND) and pin 3 connects the +VCC of the source.

Still about the power supply, for 4 ohms speakers the recommended power supply is up to ±30V and for 8 Ohms speakers up to ±38V.

The CN3 connector is for connecting to the 4 or 8 ohms speaker.

Attention: The source must be of the symmetrical type, that is, if you use a 25-volt source, it must be +25 -25 volts.

TDA7294 power supply circuit

The maximum power of the amplifier is related to the power supply and speaker impedance. See the graphs below:

Tda7294 Audio Power Amplifier Power Supply
Graph: Power X Voltage For 4 Ohm
Tda7294 Audio Power Amplifier Power Supply
Graph: Power X Voltage For 8 Ohm

You must isolate the IC body from the heatsink, using an insulator because the case will be energized. To be sure, do a continuity test between the IC casing and the heatsink.

Silicone Thermal Heatsink Pad Insulator Screw
Silicone Thermal Heatsink Pad Insulator Screw

The ideal heat sink should be at least 300 grams

BOM  to assemble the power amplifier

Last Update: 07/30/2021 00:06

C11µF a 3,3µF /63VCapacitor film1
C2, C310µF/25VElectrolytic capacitor2
C4, C51000µF/50VElectrolytic capacitor2
C6, C7, C10100nF/50VCeramic Capacitor3
C8, C922µF/50VElectrolytic capacitor2
C11220pCeramic Capacitor1
IC1TDA7294Audio amplifier integrated circuit1
Resistors 1/4W
R133kOrange, orange, orange, gold1
R210kBrown, black, orange, gold1
R3, R4, R522kRed, red, orange, gold3
R6680 ohmsBlue, gray, brown, gold1
R72,7 at 10 ohms / 1WRed, Violet, Gold, gold1
CN1Power (Supply)Terminal block 3 pin 5.08 mm1
CN2IN (Audio input)Terminal block 2 pin 5.08 mm1
CN3OUT (Audio output)Terminal block 2 pin 5.08 mm1
Solder, wires, board, box, power supply, heat sink, etc.

Download circuit board files in PDF – New PCB layout in 2021. Includes PDF, PNG, and GERBER board.



Download PDF data sheet of IC TDA7294, TDa7294S, TDA7294HS, TDA7294V — Updated.

This integrated circuit can be found on the market for a higher price than the TDA7293. The nomenclature is TDA7294V and TDA7294HS.

Buy TDA7294 DIY kit in AliExpress with worldwide free shipping

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About the author blog author. Electronics technician for the technical school of Brasilia - Brazil. Interested in electronics, circuits and technology in general.

6 thoughts on “TDA7294 amplifier circuit diagram PCB”

  1. Hello, I´m planning to buy a guitar amplifier, but seeing the low costs of the materials involved of actually constructing one I´m leaning forward to actually build a guitar head amp. Could this project work as a guitar amp? What else could I need to build a good clean channel / distort channel / 3 band eq amp head? Thanks


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