The SSM2518 is a digital input, Class-D power amplifier that combines
a digital-to-analog converter (DAC) and a sigma-delta
(Σ-Δ) Class-D modulator. This unique architecture enables
extremely low real-world power consumption from digital
audio sources with excellent audio performance. The SSM2518
is ideal for power sensitive applications, such as mobile phones
and portable media players, where system noise can corrupt
small analog signals such as those sent to an analog input audio
amplifier.
Using the SSM2518, audio data can be transmitted to the amplifier
over a standard digital audio serial interface, thereby significantly
reducing the effect of noise sources such as GSM interference or
other digital signals on the transmitted audio. The closed-loop
digital input design retains the benefits of an all digital amplifier,
yet enables very good PSRR and audio performance. The three
level, Σ-Δ Class-D modulator is designed to provide the least
amount of EMI interference, the lowest quiescent power dissipation,
and the highest audio efficiency without sacrificing
audio quality.
Input is provided via a serial audio interface, programmable to
accept all common audio formats including I2S and TDM. Control
of the IC is provided via an I2C control interface. The SSM2518
can accept a variety of input MCLK frequencies and can use
BCLK as the clock source in some configurations.
Additional features include a soft digital volume control, deemphasis,
and a programmable digital dynamic range
compressor.
The architecture of the SSM2518 provides a solution that offers
lower power and higher performance than existing DAC plus
Class-D solutions. Its digital interface also offers a better system
solution for other products whose sole audio source is digital,
such as wireless speakers, laptop PCs, portable digital televisions,
and navigation systems.
Applications
- Mobile phones
- Portable media players
- Laptop PCs
- Wireless speakers
- Portable gaming
- Small LCD televisions
- Navigation systems
