SSM2317 Filterless High Efficiency Mono 3 W Class-D Audio Amplifier

The SSM2317 is a fully integrated, high efficiency, 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 3 W of continuous output power with <1% THD + N driving a 3 Ω load from a 5.0 V supply.

The SSM2317 features a high efficiency, low noise modulation scheme that does not require any external LC output filters. The modulation continues to provide high efficiency even at low output power. It operates with 93% efficiency at 1.4 W into 8 Ω or 85% efficiency at 3 W into 3 Ω from a 5.0 V supply and has an SNR of >93 dB. Spread-spectrum pulse density modulation is used to provide lower EMI radiated emissions compared with other Class-D architectures.

Automatic level control (ALC) can be activated to suppress clipping and improve dynamic range. This feature only requires one external resistor tied to GND via the VTH pin and an activation voltage on the ALC_EN pin.

The SSM2317 has a micropower shutdown mode with a typical shutdown current of 20 nA. Shutdown is enabled by applying a logic low to the SD pin.

The device also includes pop-and-click suppression circuitry. This minimizes voltage glitches at the output during turn-on and turn-off, reducing audible noise on activation and deactivation.

The default gain of the SSM2317 is 18 dB, but users can reduce the gain by using a pair of external resistors.

The SSM2317 is specified over the commercial temperature range of −40°C to +85°C. It has built-in thermal shutdown and output short-circuit protection. It is available in a 9-ball, 1.5 mm × 1.5 mm wafer level chip scale package (WLCSP).

Applications
  • Mobile phones
  • MP3 players
  • Portable gaming
  • Portable electronics
  • Educational toys
Features and Benefits
  • Filterless Class-D amplifier with Σ-Δ modulation
  • Automatic level control (ALC) improves dynamic range and prevents clipping
  • 3 W into 3 Ω load and 1.4 W into 8 Ω load at 5.0 V supply with <10% total harmonic distortion (ALC off)
  • 700 mW into 8 Ω load at 4.2 V supply (ALC 80%)
  • 93% efficiency at 5.0 V, 1.4 W into 8 Ω speaker
  • >93 dB signal-to-noise ratio (SNR)
  • Single-supply operation from 2.5 V to 5.5 V
  • 20 nA ultralow shutdown current
  • Short-circuit and thermal protection
  • Available in 9-ball, 1.5 mm × 1.5 mm WLCSP
  • Pop-and-click suppression
  • Built-in resistors reduce board component count
  • Default fixed 18 dB or user-adjustable gain setting
  • Audio & Video Products
    Data Sheets
    Documentnote
    SSM2317: Filterless High Efficiency Mono 3 W Class-D Audio Amplifier Data Sheet (Rev. A)PDF 724 kB
    User Guides
    Documentnote
    UG-192: Evaluation Board for SSM2317 Filterless Class-D Audio AmplifierPDF 366 kB
    Order Information
    Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
    SSM2317CBZ-REEL Production9 ball WLCSP (1.46x1.46)REEL 10000-40 to 85C00.73Y
    SSM2317CBZ-REEL7 Production9 ball WLCSP (1.46x1.46)REEL 3000-40 to 85C00.73Y
    Evaluation Boards
    Part NumberDescriptionPriceRoHS
    SSM2317-EVALZEvaluation Board50.5Y
    SSM2317: Filterless High Efficiency Mono 3 W Class-D Audio Amplifier Data Sheet (Rev. A) ssm2317
    UG-192: Evaluation Board for SSM2317 Filterless Class-D Audio Amplifier ssm2317