AS3420音频开发板

enly

主动降噪芯片AS3420是一个全差分ANC扬声器驱动器芯片，为单声道蓝牙应用程序专门设计，可直接连接到共同的SoC。它也可以应用于其他类型的无线耳机。完全模拟实现降低环境背景噪声，并达到最低的功耗及最佳语音质量。AS3420蓝牙扬声器驱动芯片可用于前馈和反馈配置。由于集成了低噪声放大器，该设备可实现简单的低阶滤波器以及复杂的多阶滤波器的开发。此外，麦克风输入具有全差分低噪声放大器的功能，可达到128级的可调增益，OTP(一次性可编程)ROM可实现出厂增益设置。Features Microphone Input „

       

• 128 gain steps @ 0.375dB and MUTE with AGC        
  
• „ Differential, low noise microphone amplifier „        
  
• Single ended or differential mode „        
  
• Improved supply for electret microphone „        
  
• MIC gain OTP programmable
  

High Efficiency Headphone Amplifier „

       

• 2x34mW, 0.1% THD @ 16Ω, 1.5V supply, 100dB SNR „        
  
• Bridged mode for e.g. 300Ω loads „        
  
• Click and pop less start-up and mode switching
  

Line Input „

       

• Volume control via serial interface or volume pin „        
  
• 64 steps @ 0.75dB and MUTE, pop-free gain setting „        
  
• Single ended stereo or mono differential mode
  

ANC processing „

       

• Feed-forward cancellation „        
  
• Feed-back cancellation with filter loop transfer function definable via simple RC components „        
  
• Simple in production SW calibration „        
  
• 12-30dB noise reduction (headset dependent) „        
  
• 10-2000Hz wide frequency active noise attenuation (headset dependent)
  

Monitor Function „

       

• For assisted hearing, i.e. to monitor announcements „        
  
• Fixed (OTP prog.) ambient sound amplification to compensate headphone passive attenuation „        
  
• Volume controlled ambient sound amplification mixed with fixed (OTP prog.) attenuation of LineIn
  

Incremental Functions „

       

• ANC with or without music on the receiving path „        
  
• Improved dynamic range playback „        
  
• OTP ROM for automatic trimming during production (4 times programbable)
  

Performance Parameter „

       

• 5/3.8mA @ 1.5V stereo/mono ANC; <1µA quiescent „        
  
• Extended PSRR for 217Hz
  

Interfaces „

       

• 2-wire serial control mode & volume inputs „        
  
• Calibration via Line-In or 2-wire serial interface (patent pending) „        
  
• Single cell or fixed 1.0-1.8V supply with internal CP
  

Package „

       

• AS3400, AS3410 QFN24 [4x4mm] 0.5mm pitch „        
  
• AS3430 QFN32 [5.x5mm] 0.5mm pitch