NE571N Dual Gain Control Circuit

Overview

The NE571N is a versatile, low-cost dual gain control circuit designed for dynamic range compression and expansion applications. Each channel can be independently configured as either a compressor or expandor, making it highly flexible for various audio processing needs. The device features a full-wave rectifier for signal detection, along with temperature-compensated circuitry to ensure stable performance across varying environmental conditions.

With a dynamic range exceeding 110dB and the ability to operate at voltages as low as 6VDC, the NE571N is suitable for both consumer and professional audio equipment. Its system levels can be adjusted using external components, and distortion can be trimmed out for optimal performance.

Features

• Complete Compressor and Expandor in One IC: Each channel can function independently as a compressor or expandor.
• Temperature Compensated: Ensures stable performance across temperature variations.
• Greater than 110dB Dynamic Range: Ideal for high-fidelity audio applications.
• Low Voltage Operation: Operates down to 6VDC, making it suitable for portable and low-power devices.
• Adjustable System Levels: External components allow customization of gain and response characteristics.
• Distortion Trimming: Enables fine-tuning to minimize harmonic distortion.
• Dynamic Noise Reduction: Suitable for noise reduction systems in audio playback and recording.
• Voltage-Controlled Amplifier: Provides additional control over signal processing.

Applications

The NE571N is widely used in audio processing and dynamic range control applications, including:

• Dynamic Noise Reduction Systems: Enhances audio clarity by reducing background noise.
• Audio Compressors and Limiters: Controls dynamic range in recording and broadcasting equipment.
• Audio Expanders: Restores dynamic range in playback systems.
• Professional Audio Equipment: Used in mixers, amplifiers, and effects processors.
• Consumer Electronics: Integrated into home audio systems, portable players, and communication devices.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (VCC): 18V
• Input Voltage: ±VCC
• Operating Temperature Range: 0°C to +70°C
• Storage Temperature Range: -65°C to +150°C

Typical Operating Characteristics (VCC = 12V, TA = 25°C)

• Supply Current: 6mA (per channel)
• Input Resistance: 30kΩ
• Output Resistance: 50Ω
• Total Harmonic Distortion (THD): 0.1% (typical, adjustable)
• Gain Control Range: 80dB (typical)

Package Information

Pin Configuration (D and N Packages)

• Pin 1: RECT CAP 1
• Pin 2: RECT IN 1
• Pin 3: AG CELL IN 1
• Pin 4: GND
• Pin 5: RECT CAP 2
• Pin 6: AG CELL IN 2
• Pin 7: RECT IN 2
• Pin 8: VCC
• Pin 9: INV. IN 1
• Pin 10: RES. R3 1
• Pin 11: OUTPUT 1
• Pin 12: THD TRIM 1
• Pin 13: INV. IN 2
• Pin 14: RES. R3 2
• Pin 15: OUTPUT 2
• Pin 16: THD TRIM 2

Package Dimensions

The NE571N is available in a 16-pin DIP (Dual Inline Package) and SO (Small Outline) package. Key dimensions include:

• DIP Package: 19.3mm x 6.35mm (body length x width)
• SO Package: 10.3mm x 7.5mm (body length x width)
• Lead Pitch: 2.54mm (DIP), 1.27mm (SO)

Conclusion

The NE571N is a highly versatile and cost-effective solution for dynamic range control in audio applications. Its dual-channel design, temperature compensation, and wide dynamic range make it suitable for both professional and consumer electronics. With adjustable system levels and distortion trimming capabilities, it offers flexibility and high performance in a compact package.