TDA7294 Subwoofer Amplifier Circuit

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An audio amplifier is a circuit that transforms the small amplitude of audio input signals into a large amplitude audio signal at the output. In this tutorial, we are going to “TDA7294 Subwoofer Amplifier Circuit”. A subwoofer amplifier circuit is essentially a loudspeaker that generates low-frequency audio signals. These circuits effectively boost the quality of audio signals and improve their bass. This circuit is highly beneficial for producing low-tone frequencies.

The TDA7294 IC is used to make an audio amplifier in this article. It’s a class AB amplifier by design. It has a high level of ripple rejection. Low noise and distortion are supported by the IC. It includes a built-in thermal shutdown that guards against short circuits. The circuit, however, requires a heat sink. The integrated circuit’s frequency response ranges from 20Hz to 20KHz. Use an 8-ohm, 15-watt speaker as the load in the circuit. It’s important to remember to use a filtered power supply. Because supply ripples can induce oscillations,

Hardware Required

S.no	Component	Value	Qty
1.	DMOS Audio Amplifier IC	TDA7294	1
2.	Speaker	8Ω	1
3.	Battery	30V	1
4.	Capacitor	22uF, 10uF, 100uF, 1000uF	2, 2, 1, 1
5.	Resistors	10KΩ, 22KΩ, 680Ω, 2.7Ω	1, 3, 1, 1
6.	Ceramic Capacitor	470nF, 100nF	1, 3

Circuit Diagram

Pinouts of TDA7294

Pin No.	Pin Name	Pin Description
1	Stand-By GND	Stand-By GND, the output gets connected to ground
2	Inverting input	The Inverting input
3	Non-Inverting input	The Non-Inverting input
4	SVR	Supply Voltage Rejection is used for power supply ripple or noise rejection
5	N.C.	Not connected
6	Bootstrap	Used to step-up charge
7	+Vs Supply	Positive supply
8	-Vs Supply	Negative supply
9	Stand-by	Standby control pin used for low power mode, output runs in low current mode
10	Mute	Audio is disabled in the output
11	N.C.	Not connected
12	N.C.	Not connected
13	+Vs Power	Positive power supply
14	Out	Output pin
15	-Vs Power	Negative power supply

Working Explanation

The TDA7294 Subwoofer Amplifier Circuit uses the IC having 15pins. VM represents the mute ON and OFF voltages, which are 1.5V and 3.5V respectively in the circuit. The standby ON and OFF voltages are 1.5 volts and 3.5 volts, respectively, in VSTBY.

We attach the input coupling capacitor C8 to the non-inverting pin of the IC and serve as an input coupling capacitor. The bypass capacitors are capacitors C10C10 and C4. While C9 and C3 are power supply filter capacitors. The mute and standby switches are at S1 and S2, respectively. The feedback capacitor is C2, which is shorted between pins 14 and 6. As the load, we connect the speaker to pin 6 of the IC. When we provide the low audio input at the pin, it gives us the amplified output at the load.