Audio
MAX98356

MAX98356

PDM Input Class D Audio Power Amplifier

High-Performance, Low-Noise Digital Input Class D Amplifier


Description

The MAX98356 is a digital pulse-density modulated (PDM) input Class D power amplifier that provides Class AB audio performance with Class D efficiency. This IC offers five selectable gain settings (3dB, 6dB, 9dB, 12dB, and 15dB) set by a single gain-select input (GAIN).

View a video that highlights the features of the MAX98355/6.

The MAX98356 takes a stereo pulse density modulated (SPDM) input signal directly into the DAC. Data on the rising edge of PDM_CLK is considered left-channel data while data on the falling PDM_CLK edge is right channel. The IC can be configured to produce a left channel, right channel, or left/2 + right/2 output from the stereo input data. The IC also features an extremely robust digital audio interface with very high wideband jitter tolerance (12ns typ) on PDM_CLK.

Active emissions-limiting, edge-rate limiting, and overshoot control circuitry greatly reduce EMI. A filterless spread-spectrum modulation scheme eliminates the need for output filtering found in traditional Class D devices and reduces the component count of the solution.

The IC is available in a 9-pin WLP package (1.345mm x 1.435mm x 0.64mm) and is specified over the -40°C to +85°C temperature range.
MAX98356: Simplified Block Diagram MAX98356: Simplified Block Diagram Enlarge+

Key Features

  • Single-Supply Operation (2.5V to 5.5V)
  • 3.2W Output Power into 4Ω at 5V
  • 1.8mA Quiescent Current
  • 92% Efficiency (RL = 8Ω, POUT = 900mW, VDD = 3.7V)
  • 29µVRMS Output Noise (AV = 6dB)
  • Low 0.013% THD+N at 1kHz
  • Exceptionally High Jitter Tolerance
  • Supported PDM_CLK Rates of 1.84MHz–4.32MHz and 5.28MHz–8.64MHz
  • Supports Left, Right, or Left/2 + Right/2 Outputs
  • Sophisticated Edge Rate Control Enables Filterless Class D Outputs
  • 77dB PSRR at 217Hz
  • Low RF Susceptibility Rejects TDMA Noise from GSM Radios
  • Extensive Click-and-Pop Reduction Circuitry
  • Robust Short-Circuit and Thermal Protection
  • Available in Space-Saving Package: 1.345mm x 1.435mm WLP (0.4mm Pitch)

Applications/Uses

  • Cellular Phones
  • Notebook Computers
  • Portable Media Players
  • Tablets
  • Ultrasonic Devices
 

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