LM4861M

Product Overview

Category: Integrated Circuit (IC)

Use: Audio Power Amplifier

Characteristics: - Single supply voltage operation - Low quiescent current - High output power capability - Thermal shutdown protection - Short-circuit and thermal overload protection

Package: 8-pin SOIC (Small Outline Integrated Circuit)

Essence: The LM4861M is a mono audio power amplifier IC designed for low voltage applications. It provides high-quality amplification of audio signals with low power consumption.

Packaging/Quantity: The LM4861M is available in a standard 8-pin SOIC package. It is typically sold in reels containing multiple units.

Specifications

• Supply Voltage Range: 2.0V to 5.5V
• Quiescent Current: 4 mA (typical)
• Output Power: Up to 1.1W into 8Ω load at 5V supply
• Total Harmonic Distortion + Noise (THD+N): 0.2% (typical) at 1kHz, 1W into 8Ω load
• Shutdown Current: 0.6 μA (typical)
• Operating Temperature Range: -40°C to +85°C

Pin Configuration

The LM4861M has the following pin configuration:

```

---

| | --| VDD GND|-- Pin 1: Ground (GND) --| IN+ SHDN|-- Pin 2: Shutdown (SHDN) --| IN- OUT|-- Pin 3: Output (OUT) --| BP VDD|-- Pin 4: Positive Power Supply (VDD) |___________| ```

Functional Features

1. Single Supply Operation: The LM4861M can operate from a single supply voltage, making it suitable for battery-powered applications.

2. Low Quiescent Current: The IC has low quiescent current consumption, resulting in extended battery life.

3. High Output Power Capability: Despite its small size, the LM4861M can deliver high output power to drive speakers efficiently.

4. Thermal Shutdown Protection: The IC incorporates thermal shutdown protection, which prevents damage due to excessive heat.

5. Short-Circuit and Thermal Overload Protection: The LM4861M includes built-in short-circuit and thermal overload protection, ensuring safe operation under fault conditions.

Advantages

• Low power consumption
• Small package size
• High-quality audio amplification
• Built-in protection features

Disadvantages

• Mono output only
• Limited output power compared to larger amplifiers

Working Principles

The LM4861M is based on Class AB amplifier topology. It amplifies the input audio signal using a combination of transistors and feedback circuitry. The amplified signal is then delivered to the output pin, driving the connected speaker.

Detailed Application Field Plans

The LM4861M is commonly used in various portable audio devices, such as:

1. Mobile phones
2. Portable media players
3. Bluetooth speakers
4. Headphones and earphones
5. Personal digital assistants (PDAs)

Its low power consumption, small form factor, and high-quality audio amplification make it ideal for these applications.

Alternative Models

1. LM4861: Similar to LM4861M but available in a different package (e.g., DIP-8).
2. LM4861N: Similar to LM4861M but with different pin configuration.
3. LM4861MX: Surface mount version of LM4861M with improved thermal characteristics.

These alternative models offer similar functionality and can be used as replacements for the LM4861M in various applications.

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