EVAL-SSM2375Z: 3.7W @ 3Ω Mono, 2.5 ~ 5.5V in

The SSM2375 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.

Spread spectrum pulse density modulation (PDM) is used to provide lower EMI-radiated emissions compared with other Class-D architectures. The inherent randomized nature of spread spectrum PDM eliminates clock intermodulation (beating effect) of several amplifiers in close proximity. The SSM2375 includes an optional modulation select pin that enables a low EMI mode, which significantly reduces the radiated emissions at the Class-D outputs, particularly above 100 MHz. With this option selected, the SSM2375 can pass FCC Class B radiated emissions testing with a 50 cm unshielded speaker cable without any external filtering.

The device also includes a flexible gain select pin that only requires one series resistor to select among 0 dB, 3 dB, 6 dB, 9 dB, or 12 dB. The benefit of this is to improve gain matching between multiple SSM2375 devices within a single application as compared to using external resistors to set gain.

The user guide describes how to configure and use the SSM2375 evaluation board. It is recommended that the user guide be read in conjunction with the SSM2375 data sheet, which provides specifications, internal block diagrams, and application guidance for the amplifier IC.

The SSM2375 evaluation board carries a complete application circuit for driving a loudspeaker.