IRS2092 Class-D Audio Amplifier: A High-Power Circuit Design Guide

If you want to build a high-power, low-heat-dissipating, and crystal-clear sound quality audio amplifier, the IRS2092 IC is the best solution for you. It is a modern Class-D amplifier driver that ensures maximum efficiency using Pulse Width Modulation (PWM) technology.

Limitations of Conventional Amplifier Circuits:

When building a high-quality audio amplifier using conventional transistors (BJT), you need to use countless transistors and other associated electronic components for the audio output, driver, and input sections. Even if the PCB design for so many components is accurate according to the circuit diagram, technical errors due to a designer with less experience in audio technology can cause unwanted noise or cause the output transistors to overheat.

Advantages of the IRS2092 IC:

On the other hand, a single IRS2092 IC can be used to build an amplifier, replacing countless transistors and a complex circuit. This IC performs the work of many transistors and components, significantly reducing the possibility of technical errors in the PCB design. As a result, the sound quality is crisp and clear, and there is virtually no noise.

Guide to Building a Flawless Amplifier:

To build a reliable and perfect audio amplifier using the IRS2092 IC, you need to follow some specific rules and methods. This article provides detailed guidelines on these important topics. Please read the entire page carefully to build a flawless audio amplifier.

Key Features of the IRS2092 IC

The IRS2092 IC integrates a PWM controller and a MOSFET driver into a single chip. Its biggest advantage is that it directly controls the audio signal and switches the MOSFETs at extremely high speed. As a result, the amplifier achieves more than 90% efficiency and produces relatively less heat.

This IC is available in two main packages:

PDIP16: This is a 16-pin Dual In-line Package. Due to its larger size, it is very easy to solder and is suitable for hand-built circuits.

SOIC16N: This is a small 16-pin Surface Mount Package (SMD). It is typically used in commercial production where a smaller design is essential.

MOSFET Audio Amplifier Circuit Diagram Using  IRS2092 PWM Driver IC

The schematic circuit diagram for the audio amplifier is published below. It uses two IRF450 MOSFETs (N-Channel) in the output section. For this circuit, we recommend using the PDIP16 package of the IRS2092 IC. Soldering the IC directly to the board instead of using an IC base will ensure long-term durability.

This circuit requires a 10-ampere 60V CT 60V AC transformer for the main power supply. Additionally, for the 12V VCC supply, a separate 2-ampere full-wave transformer with a maximum output of 18V and a 7812 regulator IC must be used. In this case, the values of resistors R9 and R12 for the voltage supply to the VSS and VAA pins of the IRS2092 will be 4.7KΩ, with more details available in the component list below.

If you wish to build a -35V 0V +35V amplifier using the SOIC16N package of the IRS2092 IC, you can find the detailed circuit diagram and information from the IC manufacturer's link.

Circuit diagram of a high-power, low-noise Class-D audio amplifier based on the IRS2092 IC. This diagram shows the IRF450 MOSFETs used and the additional noise filtering system.

Resistors Value of The Circuit Diagram

Items:	Value:	V/W/A:	Items:	Value:	V/W/A:
R1	4Ω	2 Watt	R2	1Ω	1W
R3	10Ω	2 W	R4	10Ω	2W
R5	3.3KΩ	1/2 W	R6	8.2KΩ	1/2W
R7	1.2KΩ	1/2 W	R8	8.2KΩ	1/4W
R9	510Ω	1/2W	R10	10KΩ	1/4W
R11	3.3KΩ	1/2 W	R12	2.7KΩ	1/2W
R13	47KΩ	1/2W	R14	1KΩ	1/2W
R15	33KΩ	1/2W	R16	10KΩ	1/2W
R17	10KΩ	1/2W	R18	4.7Ω	1/2W
R	Ω	W	R	Ω	W

Capacitor  Value (With Minimum Voltage)

Items:	Value:	V/W/A:	Components:	Value:	V/W/A:
C1	0.047µF	400V	C2	0.1µF	200V
C3	0.1µF	200V	C4	100µF	35V
C5	10µF	35V	C6	10µF	35V
C7	10µF	35V	C8	1nF	35V
C9	1nF	35V	C10	1nF	35V
C11	1nF	35V	C12	10µF	35V
C13	102	35V	C14	10µF	35V
C15	150PF	35V	C16	10000µF	100V
C17	10000µF	100V	C	µF	Volt
C	µF	Volt	C	µF	Volt

Diodes: D1, D2 - BAV19WS

U1- IRS2092.   Q1, Q2 - IRF450 MOSFET, L1- 22µH

Speaker Characteristics

To get the best sound quality and performance from this amplifier, selecting the right speaker is crucial. We have some suggestions to help you choose the best fit for your amplifier.

• Speaker Wattage: The speaker's power rating should always be higher than the amplifier's output. For this amplifier, we recommend using a speaker rated at 300 to 400 watts for an 8-Ohm setup, or 500 to 600 watts or more for a 4-Ohm setup.

• Speaker Size: This amplifier is well-suited for larger speakers that can handle powerful, deep bass. For a full, rich sound, we suggest a 12 to 15-inch woofer or subwoofer.

• Impedance: This amplifier will work effectively with either a 4-Ohm or an 8-Ohm speaker. The power output will be higher when a 4-Ohm speaker is used.

Amplifier Circuit Design: A Step-by-Step Guide

This proven circuit design has been created to be highly stable and produce minimal noise.

1. Input Section and Noise Filtering:

To eliminate unwanted noise from the audio input, we have taken a special measure. A 1000 pF capacitor has been connected from the audio input capacitor to the ground. This capacitor acts as a low-pass filter and blocks high-frequency noise before it can reach the IC's input, which prevents unwanted sounds and keeps the MOSFETs from overheating.

2. Power Supply Design:

A powerful and reliable power supply is essential for the stable operation of the amplifier. This circuit uses a dual power supply.

• For the PDIP16 package: You can use a -60V, Ground (GND), and +60V supply. In this case, the IRFP450 power MOSFET has been used, which is suitable for this voltage.

• For the SOIC16N package: A -30V, Ground (GND), and +30V supply has been used. In this case, you can select the MOSFET number according to your needs.

3. Additional Filtering and Reliability:

To ensure long-term reliability and reduce voltage drop, we have used additional filtering capacitors. The main filter capacitors are placed near the power supply, and an extra 1000µF capacitor has been used on the amplifier PCB's power supply line. This acts as a local voltage reservoir near the MOSFETs, which reduces voltage drop and improves circuit performance.

This circuit design has been prepared based on 35 years of experience, paying special attention to every component and connection. It is not just a diagram; it is a reliable and high-quality electronic project.

You can build this high-power amplifier yourself by following this circuit diagram. I wish you success with your project.

Important Tips for Low-Noise and Long-Lasting Performance

To build a high-quality amplifier, a good circuit diagram alone is not enough; its physical setup is equally important. Following these guidelines will ensure your amplifier is completely noise-free and reliable.

Board Placement:

Place the amplifier board in the cabinet so that the MOSFETs are on the back side. This will help with proper airflow and heat dissipation.

Speaker Connection:

Make sure the speaker wires are not too long. Install the speaker connectors close to the board's output section. This will reduce noise caused by feedback signals.

High-Quality Cables:

For audio input connections, you must use a good quality co-axial cable. It prevents unwanted external signals from entering the input.

Tone Control Circuit:

A good tone control circuit is essential for shaping the sound from a high-power amplifier. It allows you to adjust the bass, treble, and midrange frequencies to match your listening preferences. Since this amplifier is so powerful, adding a quality tone control circuit can help you achieve the perfect audio balance. You can even build one yourself using simple transistors without complex ICs like 4558 or LM324.

Proper Grounding:

To eliminate noise, solder a wire from the GND of the board's audio input section to the front of the cabinet's chassis. This will prevent ground loops.

Power Transformer Placement:

Place the power transformer as far as possible from the board's audio input section. This will protect the circuit from electromagnetic noise (EMI) coming from the transformer.

Bridge Rectifier and Filter Capacitors:

Install the KB3510 bridge rectifier with a suitable heatsink at the back of the cabinet. Do not connect the amplifier's main power supply directly to the bridge rectifier; instead, connect it to the main filter capacitors. Also, solder a thick wire from the series connection (GND) of the two main filter capacitors to the rear of the cabinet's chassis.

PCB Design:

When designing the PCB, maintain a specific distance between the ground of the output circuit and the ground of the input circuit.

By following these rules, you will get a noise-free, clear, and powerful sound from your amplifier.