LM4860M Bridge-Connected Audio Power Amplifier

Overview

The LM4860M is a high-performance bridge-connected audio power amplifier designed to deliver high-quality audio output with minimal distortion. This component is capable of providing 1W of continuous average power to an 8Ω load while maintaining less than 1% Total Harmonic Distortion plus Noise (THD+N) across the entire audio spectrum. The LM4860M is ideal for applications requiring efficient and compact audio amplification, such as portable electronics, multimedia speakers, and communication devices.

This amplifier integrates several advanced features, including a low-power shutdown mode for energy efficiency, thermal shutdown protection for reliability, and dedicated headphone control inputs for versatile audio routing. Its compact package and robust performance make it a preferred choice for space-constrained and power-sensitive designs.

Features

• High Output Power: Delivers 1W continuous average power into an 8Ω load with <1% THD+N.
• Low Power Consumption: Features an externally controlled shutdown mode to minimize power usage when inactive.
• Thermal Protection: Includes an internal thermal shutdown mechanism to prevent overheating and ensure long-term reliability.
• Headphone Control: Equipped with two headphone control inputs and a headphone sense output for flexible audio routing.
• Wide Supply Voltage Range: Operates efficiently across a broad voltage range, making it suitable for battery-powered applications.
• Low Quiescent Current: Optimized for minimal power draw during idle states, enhancing battery life.
• Bridge-Tied Load (BTL) Configuration: Eliminates the need for output coupling capacitors, reducing component count and cost.

Applications

The LM4860M is designed for a variety of audio amplification applications, including but not limited to:

• Portable audio devices (e.g., MP3 players, smartphones, tablets)
• Multimedia speakers and soundbars
• Gaming consoles and handheld gaming devices
• Communication systems (e.g., intercoms, two-way radios)
• Television and monitor audio subsystems
• Automotive infotainment systems (where applicable)

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_DD): 6V
• Output Power (P_OUT): 1W (continuous, 8Ω load)
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

Typical Performance Characteristics

• Total Harmonic Distortion + Noise (THD+N): <1% at 1W, 1kHz
• Quiescent Current (I_Q): 4mA (typical)
• Shutdown Current (I_SD): 0.1µA (typical)
• Signal-to-Noise Ratio (SNR): >90dB
• Gain Bandwidth Product: 1.2MHz (typical)

Package Information

The LM4860M is available in a compact and industry-standard package, ensuring ease of integration into various PCB designs. Below are the key package details:

• Package Type: SOIC-8 (Small Outline Integrated Circuit)
• Dimensions: 4.9mm x 3.9mm (body size)
• Pin Count: 8
• Mounting Style: Surface Mount Technology (SMT)
• Lead Material: Matte Tin (Sn) plating for improved solderability

Pin Configuration

• Pin 1 (Shutdown): Active-low shutdown control input.
• Pin 2 (Input 1): Non-inverting input for the amplifier.
• Pin 3 (Input 2): Inverting input for the amplifier.
• Pin 4 (GND): Ground reference for the IC.
• Pin 5 (Output 2): Second amplifier output (bridge-tied load configuration).
• Pin 6 (V_DD): Positive supply voltage input.
• Pin 7 (Headphone Sense): Output indicating headphone connection status.
• Pin 8 (Output 1): First amplifier output (bridge-tied load configuration).

Conclusion

The LM4860M is a versatile and efficient audio power amplifier that combines high performance with advanced features such as thermal protection and low-power shutdown mode. Its compact SOIC-8 package and robust electrical characteristics make it an excellent choice for a wide range of audio applications, from portable electronics to multimedia systems. Engineers and designers can rely on the LM4860M for delivering clear, high-fidelity audio while maintaining energy efficiency and reliability.