LM4804LQX

LM4804LQX Application Field and Working Principle

The LM4804LQX is a high-performance, quad Class AB audio power amplifier designed to deliver low-noise and distortion performance in a wide variety of audio applications. It operates over a wide range of 10kHz to 3MHz, allowing it to be used with a wide range of audio sources. The LM4804LQX is designed to provide high-quality stereo output while drawing minimal current, making it suitable for powering a wide range of audio applications including portable, broadcast, and automotive audio systems.

Input Stage Circuitry

The input stage circuitry of the LM4804LQX serves two main functions. First, it provides a low-noise, low-distortion signal path from the signal source to the power amplifier stages. Second, it provides signal conditioning and pre-emphasis to enhance the performance of the final output signal. The input stage circuitry includes two differential amplifiers with second-order active low-pass filters and two buffer amplifiers for reducing noise.

Voltage Gain

The voltage gain of the LM4804LQX is controlled by a series of external resistors and capacitors. The input stage circuitry can be adjusted to provide a gain of 3x, 5x, 10x, 20x, or 40x. The voltage gain allows users to match the output level of the power amplifier to the signal source, allowing precise control of the signal drive level.

Output Stage Circuitry

The output stage circuitry of the LM4804LQX consists of four independent, Class AB audio power amplifier channels. Each of the four channels has independent volume control and signal conditioning circuitry. The signal conditioning circuitry includes low-pass filters and high-pass crossover filters for precise signal shaping. The output stages are designed to deliver very low distortion over the wide audio signal bandwidth. The LM4804LQX also features a signal detect circuit, which makes it compatible with virtually any audio system.

Power Supply

The LM4804LQX can be powered from a wide range of power supply voltages. It is designed to run from a single 5V to 20V supply, or from dual +/- 5V to 12V supplies. It also has several power-saving features that allow the amplifier to draw minimal current when idling or under low signal conditions. This makes the LM4804LQX an ideal choice for use in portable and automotive applications, where low power consumption is critical.

Conclusion

The LM4804LQX is a high-performance, quad Class AB audio power amplifier designed to deliver low-noise and distortion performance in a wide variety of audio applications. It has a wide bandwidth of 10 kHz to 3 MHz, allowing it to be used with a wide range of audio sources. Its low-noise and low-distortion output stage, signal conditioning circuitry, and power-saving features make it an excellent choice for use in portable, broadcast, and automotive audio systems.