Making a LM4766 dual 40W amplifier circuit

The NS LM4766, launched by a US company, is a two-channel power amplifier integrated circuit. Each channel can output an average power of 40W at an 8-ohm load, with distortion levels lower than 0.1%. It is part of National Semiconductor's product range and is classified under the "Overture" series, known for being high-end single-chip dual-channel audio power amplifiers. The LM4766 boasts attractive specifications, including a good signal-to-noise ratio and low distortion. It is capable of operating within the audible frequency range of human hearing, exhibiting only 0.06% distortion at a 30W output. The power design capabilities of National Semiconductor are evident, suggesting that with excellent circuit design, the LM4766 could achieve high-fidelity sound. However, it should be noted that achieving a high-fidelity effect is not guaranteed with every application of the LM4766; amplifier design is a systematic endeavor that requires careful consideration to achieve optimal performance. The internal design includes robust protection measures, such as automatic shutdown at 165°C and automatic recovery at 155°C, as well as protections against overvoltage, undervoltage, overload, and overheating. The LM4766 also features patented SPIKE peak protection, ensuring safe operation within the amplifier's characteristic curve. The design of the LM4766 allows for considerable safety performance when used as a power amplifier. Additionally, both channels of the LM4766 are equipped with separate mute circuits, controlled by two pins, which disconnect the input to prevent output signals during the power-up process, thus minimizing boot-up impact. According to the datasheet, when supplied with a power voltage of ±30V and adequate signal stimulus, the LM4766 can deliver 40W of output power to drive speaker units, making it suitable for most multimedia speakers. Typically, a listening power range of 1-2W is sufficient for casual music enjoyment. Based on prior experience, while the LM4766 may not produce extreme power, it offers strong drive capabilities with a thick, rich sound profile. It is particularly effective for small to medium-sized speakers, helping to avoid issues such as thin or fragile sound quality, and can even deliver a tube-like listening experience.

The LM4766 is designed with a dual-channel architecture that facilitates high-quality audio amplification. Each channel operates independently, allowing for stereo sound reproduction with minimal crosstalk. The integrated circuit is optimized for audio applications, featuring low total harmonic distortion (THD) and a high signal-to-noise ratio (SNR), which contribute to the clarity and fidelity of the audio output.

The internal protection mechanisms are crucial for maintaining reliability and longevity in various operating conditions. The thermal shutdown feature prevents damage due to excessive heat, while the SPIKE protection safeguards against sudden voltage spikes that could otherwise compromise the amplifier's performance. These features make the LM4766 suitable for a range of applications, from home audio systems to professional audio equipment.

The mute function is particularly beneficial in applications where noise during power-up or switching is a concern. By disconnecting the input signal during these times, the LM4766 minimizes audible pops or clicks that could detract from the listening experience.

In terms of power supply requirements, the LM4766 is designed to operate with a dual power supply providing ±30V. This voltage level is essential for achieving the maximum output power of 40W per channel. The design allows for flexibility in integration into various audio systems, ensuring compatibility with a wide range of speakers and audio sources.

Overall, the LM4766 represents a well-engineered solution for audio amplification, combining robust performance characteristics with essential protective features, making it a reliable choice for both consumer and professional audio applications.NS LM4766 US company launched a two-channel power amplifier integrated circuits, each channel on 8 load can output 40W average power, and distortion is less than 0.1%, in National Semiconductor's product range, LM4766 is classified "Overture (overture)" series, are among the most high-end single-chip dual-channel audio power amplifier manifold. LM4766 indicators are very attractive, good signal to noise ratio and distortion power integrated circuits which are very good, LM4766 can do in the human ear can hear the band, with only 0.06% in the case of distortion and 30W power output noise value, power design capability manifold national semiconductor is evident.

We have reason to believe that if with excellent circuit design, LM4766 can play the effect may not be used only if "reach HI-FI" will be able to comment. Of course, it does not mean that whenever using LM4766 power blocks, we will be able to achieve HI-FI effect!

Amplifier design is a systematic project, some so-so casually lap, naturally will not get any good performance. The internal manifold also has a perfect protection measures: (output 165 automatically shut down, automatically return to work at 155 ) overvoltage, undervoltage, overload, over-temperature, and its patent - SPIKE peak protection safe operating area (guarantee integrated amplifier final stage of the pipe work safe operating area of the characteristic curve and other functions).

It can be said, using the LM4766 power amplifier design success, can often achieve considerable safety performance. In addition, two channels inside the LM4766 has a separate mute circuit and leads by two pins. Its role is to close the LM4766's input, the internal amplifier has no output signal, after which the two pins connected in a certain way, to eliminate the impact of the boot process.

From DATASHEET we can see, the power supply voltage reaches the LM4766 + -30V, and there is sufficient signal stimulus, then, LM4766 40W output power push speaker unit, this power has been able to put most of the multimedia speaker push instill obedience. What's more, I usually listen to music when probably will 1,2W power sufficient rang. Based on past experience, LM4766 power although not great, but the thrust was strong, sound thick, rich, soft Naiting grace, using it to promote small and medium sized speakers, can effectively avoid the small speakers sound prone to thin, fragile and other issues, tube-like machine can even enjoy the sound.