The SSM2375 and SSM2380 Class D audio amplifiers from Analog Devices give audio system designers the option of fixed or programmable gain settings combined with low noise and superior audio performance.

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The SSM2380 low-power, stereo Class D amplifier is the first in its class to incorporate an I²C interface, which allows gain stages to be set from 1 dB to 24 dB (plus mute) in 47 distinct steps with no other external components required. The programmable interface also enables independent L/R channel shutdown, a variable low-EMI (electromagnetic interference) emission control mode, and programmable automatic level control (ALC) functions for speaker protection. The SSM2380 achieves a 100-dB signal-to-noise ratio (SNR) and is 93% efficient at 5 V while running at 1.4 W into an 8-Ω speaker.

The SSM2375 is a high-performance, fully integrated Class D amplifier with single-pin five-level gain setting in 3-dB stages from 0 to 12 dB. The single-pin gain setting eliminates input resistors and ensures a better input match that reduces noise and improves audio quality. Operating from a single 2.5- to 5-V supply, the amplifier delivers 3 W continuous with less than 1% total harmonic distortion (THD) when driving a 3-Ω load from a 5-V supply.

Also, the SSM2375 offers greater than 98-dB SNR performance. At 215 Hz, it achieves an 80-dB power-supply rejection ratio (PSRR) that is 10 dB higher than the closest competing Class D amplifier. The amplifier’s low noise and EMI allow engineers more flexibility to place the speaker on the board in end-product designs.

Supplied in a nine-lead wafer-level chip-scale package (WLCSP), the SSM2375 is list priced at 57 cents each in 1000-piece quantities. The SSM2380, in a 16-lead package, costs 75 cents each in 1000-piece quantities.

Analog Devices