The SSM2315 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 SSM2315 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 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 >103 dB. Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures. The SSM2315 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 suppression circuitry 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 SSM2315 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 default gain of the SSM2315 is 6 dB, but users can reduce the gain by using a pair of external resistors. The SSM2315 is specified over the industrial 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 * Filterless Class-D amplifier with Σ-Δ modulation * No sync necessary when using multiple Class-D amplifiers from Analog Devices, Inc. * 3 W into 3 Ω load and 1.4 W into 8 Ω load at 5.0 V supply with <1% total harmonic distortion (THD + N) * 93% 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 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 6 dB or user adjustable gain setting