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1.2W, Low-EMI, Filterless, Class D Audio Amplifier

1.2W, Low-EMI, Filterless Class D Audio Amplifiers for Class AB Amplifier Performance with Class D Efficiency that Conserve Board Space and Extend Battery Life

Product Details

Key Features

Simplified Block Diagram

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Key Features

  • Filterless Amplifier Passes FCC Radiated Emissions Standards with 100mm of Cable
  • Unique Spread-Spectrum Mode Offers 5dB Emissions Improvement Over Conventional Methods
  • Optional External SYNC Input
  • Simple Master-Slave Setup for Stereo Operation
  • 88% Efficiency
  • 1.2W into 8Ω
  • Low 0.1% THD+N
  • High PSRR (72dB at 217Hz)
  • Integrated Click-and-Pop Suppression
  • 1.8V Logic-Compatible
  • Low Quiescent Current (4mA)
  • Low-Power Shutdown Mode (0.1µA)
  • Short-Circuit and Thermal-Overload Protection
  • Available in Thermally Efficient, Space-Saving 12-Bump UCSP Package (1.5mm x 2mm x 0.6mm)

Applications/Uses

  • Cellular Phones
  • MP3 Players
  • PDAs
  • Portable Audio

Description

The MAX9746 mono Class D audio power amplifier provides Class AB amplifier performance with Class D efficiency, conserving board space and extending battery life. The MAX9746 is designed specifically for systems using 1.8V logic interface. Using a Class D architecture, the MAX9746 delivers 1.2W into an 8Ω load while offering efficiencies near 90%. A low-EMI modulation scheme renders the traditional Class D output filter unnecessary.

The MAX9746 offers two modulation schemes: a fixed-frequency (FFM) mode, and a spread-spectrum (SSM) mode that reduces EMI-radiated emissions due to the modulation frequency. Furthermore, the MAX9746 oscillator can be synchronized to an external clock through the SYNC input, allowing the switching frequency to be user defined. The SYNC input also allows multiple MAX9746s to be cascaded and frequency locked, minimizing interference due to clock intermodulation. The device utilizes a fully differential architecture, a fullbridged output, and comprehensive click-and-pop suppression. The gain of the MAX9746 is set internally further reducing external component count.

The MAX9746 features high 72dB PSRR, a low 0.1% THD+N, and SNR in excess of 90dB. Short-circuit and thermal-overload protection prevent the device from damage during a fault condition. The MAX9746 is available in a 12-bump UCSP™ (1.5mm x 2mm x 0.6mm) package. The MAX9746 is specified over the extended -40°C to +85°C temperature range.

Simplified Block Diagram

MAX9746: Block Diagram MAX9746: Block Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .