The SSM2335 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 SSM2335 features a high efficiency, low noise modulation scheme that requires no external LC output filters. The modu-lation 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 >96 dB. Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures.
The SSM2335 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 SSM2335 provides excellent rejection of common-mode noise on the input. Input coupling capacitors can be omitted if the input dc common-mode voltage is approximately VDD/2.
The default gain of the SSM2335 is 18 dB, but users can reduce the gain by using a pair of external resistors (see the Gain section).
The SSM2335 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
