SSM2311

The SSM2311 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 less than 1% THD + N driving a 3 Ω load from a 5.0 V supply.

The SSM2311 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 90% 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 that is better than 98 dB. Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures.

The SSM2311 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 turnoff, thus reducing audible noise on activation and deactivation. The fully differential input of the SSM2311 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 V_DD/2.

The default gain of SSM2311 is 18 dB, but users can reduce the gain by using a pair of external resistors.

The SSM2311 is specified over the industrial temperature range (−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