NS4251

NS4251 is available in a QFN3×3-16 package with a rated operating temperature range of -40°C to 85°C. NS4251 is a 3W stereo audio power amplifier featuring Class AB/Class D operating mode switching and analog 3D surround sound. When a headphone plug is inserted into the jack, the audio power amplifier drives stereo headphones in single-ended mode. A single control pin switches the device between Class AB and Class D operating modes to suit different application environments. Even in Class D mode, NS4251 employs advanced technology to significantly reduce EMI across the full bandwidth, minimizing interference with other components. To simplify audio system design, NS4251 integrates both bridge-tied speaker amplifier mode and single-ended stereo headphone amplifier mode on a single chip. NS4251's filterless PWM modulation architecture and built-in feedback resistors reduce external components, PCB area, and system cost. NS4251 incorporates overcurrent protection, over-temperature protection, and undervoltage protection to effectively safeguard the device against damage under abnormal operating conditions. With spread-spectrum technology and a fully optimized circuit design, efficiency of up to 90% makes it ideal for mobile phones and other portable audio products.

Applications

• Laptop computers
• Desktop computers
• Low-voltage audio systems

Key features

• Class AB/D operation mode switching
• Analog 3D surround sound
• 3W output power
• 0.1% THD (1W output, 5V supply)
• Excellent full-bandwidth EMI suppression
• Excellent pop & click noise suppression
• Up to 90%+ efficiency (Class D mode)
• High PSRR: -80dB (217Hz)
• Operating voltage range: 3.0V ~ 5.5V
• Overcurrent, overtemperature, and undervoltage protection
• Stereo headphone amplifier mode
• QFN3×3-16 package