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1.8W, Filterless, Ultra-Low EMI, Stereo Class D Audio Power Amplifier

1.8W Ultra-Low EMI Stereo Amplifier that Passes FCC Radiation Emissions Standards

Product Details

Key Features

Simplified Block Diagram

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Key Features

  • Filterless Amplifier Passes FCC-Radiation Emissions Standards with 6in of Cable
  • Unique Spread-Spectrum Mode and Active Emissions Limiting Achieves Better than 15dB Margin Under FCC Limit
  • Zero Dead Time (ZDT) H-Bridge Maintains Good THD+N Performance
  • Single-Supply Operation (2.5V to 5.5V)
  • Stereo Output (4Ω, VDD = 5V, THD+N = 1%, POUT = 1.8W)
  • No LC Output Filter Required
  • 85% Efficiency (RL = 8Ω, POUT = 600mW)
  • Less Than 0.1% THD+N
  • High 80dB PSRR
  • Fully Differential Inputs
  • Integrated Click-and-Pop Suppression
  • Low-Power Shutdown Mode (0.1µA)
  • Short-Circuit and Thermal-Overload Protection
  • Pin-for-Pin Compatible with the MAX9701
  • Available in Thermally Efficient, Space-Saving Packages
    • 24-Pin TQFN-EP (4mm x 4mm x 0.8mm)
    • 20-Bump UCSP (2mm x 2.5mm x 0.6mm)

Applications/Uses

  • Cellular/Multimedia Phones
  • Handheld Gaming Consoles
  • MP3 Players
  • Notebooks

Description

The MAX9773 3rd-generation, ultra-low EMI, stereo, Class D audio power amplifier provides Class AB performance with Class D efficiency. The MAX9773 delivers 1.8W per channel into a 4Ω load, and offers efficiencies above 90%. Active emissions limiting (AEL) circuitry greatly reduces EMI by actively controlling the output FET gate transitions under all possible transient conditions. AEL controls high-frequency emissions resulting from conventional Class D free-wheeling behavior in the presence of an inductive load. Zero-dead- time (ZDT) technology maintains state-of-the-art efficiency and THD+N performance by allowing the output FETs to switch simultaneously without cross conduction. A spread-spectrum modulation scheme eliminates the need for output filtering found in traditional Class D devices. These design concepts reduce component count and extend battery life.

The MAX9773 offers two modulation schemes: a fixed-frequency (FFM) mode, and a spread-spectrum (SSM) mode that reduces EMI-radiated emissions. The MAX9773 oscillator can be synchronized to an external clock through the SYNC input, allowing synchronization of multiple Maxim Class D amplifiers. The sync output (SYNC_OUT) can be used for a master-slave application where more channels are required. The MAX9773 features a fully differential architecture, a full bridge-tied load (BTL) output, and comprehensive click-and-pop suppression. The device features internally set gains of 12dB, 15.6dB, 20dB, and 26dB selected through two gain-select inputs, further reducing external component count.

The MAX9773 features high 80dB PSRR, less than 0.1% THD+N, and SNR in excess of 88dB. Short-circuit and thermal-overload protection prevent the device from being damaged during a fault condition. The MAX9773 is available in 24-pin thin QFN-EP (4mm x 4mm x 0.8mm), and 20-bump UCSP™ (2mm x 2.5mm x 0.6mm) packages. The MAX9773 is specified over the extended -40°C to +85°C temperature range.

Simplified Block Diagram

MAX9773: Block Diagram MAX9773: 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 .