SSM2356 2 × 2W Filterless Class-D Stereo Audio Amplifier

The SSM2356 is a fully integrated, high efficiency, stereo Class-D audio amplifier. It is designed to maximize performance for mobile phone applications. The application circuit requires a minimum of external components and operates from a single 2.5 V to 5.5 V supply. It is capable of delivering 2 × 2W of contin-uous output power with <1% THD + N driving a 4 Ω load from a 5.0 V supply.

The SSM2356 features a high efficiency, low noise modulation scheme that requires no external LC output filters. The modulation continues to provide high efficiency even at low output power. It operates with 92% efficiency at 1.4 W into 8 Ω or 85% efficiency at 2.0 W into 4 Ω from a 5.0 V supply and has an SNR of >103 dB.

Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures. The SSM2356 includes an optional modulation select pin (ultralow EMI emission mode) that significantly reduces the radiated emissions at the Class-D outputs, particularly above 100 MHz.

The SSM2356 has a micropower shutdown mode with a typical shutdown current of 20 nA. Shutdown is enabled by applying a logic low to the SDNR and SDNL pins. The device also includes pop-and-click suppression circuitry that minimizes voltage glitches at the output during turn-on and turn-off, reducing audible noise on activation and deactivation.

The fully differential input of the SSM2356 provides excellent rejection of common-mode noise on the input. Input coupling capacitors can be omitted if the dc input common-mode voltage is approximately VDD/2. The preset gain of SSM2356 can be selected between 6 dB and 18 dB with no external components and no change to the input impedance. Gain can be further reduced to a user-defined setting by inserting series external resistors at the inputs.

The SSM2356 is specified over the commercial temperature range (−40°C to +85°C). It has built-in thermal shutdown and output short-circuit protection. It is available in a 16-ball, 1.66 mm × 1.66 mm wafer level chip scale package (WLCSP).

Applications
  • Mobile phones
  • MP3 players
  • Portable gaming
  • Portable electronics
Features and Benefits
  • Filterless stereo Class-D amplifier with Σ-Δ modulation
  • No sync necessary when using multiple Class-D amplifiers from Analog Devices, Inc.
  • 2 × 2W into 4 Ω load and 2x1.4 W into 8 Ω load at 5.0 V supply with <1% total harmonic distortion (THD + N)
  • 92% efficiency at 5.0 V, 1.4 W into 8 Ω speaker
  • >103 dB signal-to-noise ratio (SNR)
  • Single-supply operation from 2.5 V to 5.5 V
  • 20 nA shutdown current; left/right channel control
  • Short-circuit and thermal protection
  • Available in a 16-ball, 1.66 mm × 1.66 mm WLCSP
  • Pop-and-click suppression
  • Built-in resistors that reduce board component count
  • User-selectable 6 dB or 18 dB gain setting
  • User-selectable ultralow EMI emission mode
  • Audio & Video Products
    Data Sheets
    Documentnote
    SSM2356: 2 × 2W Filterless Class-D Stereo Audio Amplifier Data Sheet (Rev. A)PDF 633 kB
    User Guides
    Documentnote
    UG-193: Evaluation Board for SSM2356 Filterless Class-D Audio AmplifierPDF 379 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    SSM2356CBZ-RL Last Time Buy16 Ball WLCSP(1.7X1.7X.60)REEL 10000-40 to 85C00.9Y
    SSM2356CBZ-RL7 Last Time Buy16 Ball WLCSP(1.7X1.7X.60)REEL 3000-40 to 85C00.9Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    EVAL-SSM2356ZEvaluation Board-1Y
    SSM2356: 2 × 2W Filterless Class-D Stereo Audio Amplifier Data Sheet (Rev. A) ssm2356
    UG-193: Evaluation Board for SSM2356 Filterless Class-D Audio Amplifier ssm2356