Digital Input Stereo, 2 W, Class-D
Audio Power Amplifier
Data Sheet
SSM2518
FEATURES
GENERAL DESCRIPTION
Filterless, digital input Class-D amplifier
Serial digital audio interface supports common formats
I2S, left justified, right justified, TDM1-16, and PCM
2 channels × 2 W into 4 Ω and 2 channels × 1.4 W into 8 Ω
with 1% THD+N, when using a 5 V supply
I2C control interface or standalone operation
91% efficiency at full scale into an 8 Ω load
97 dB signal-to-noise ratio (SNR), A-weighted
80 dB power supply rejection ratio (PSRR) at 217 Hz
Digital volume control: −71.25 dB to +24 dB in 0.375 dB steps
Supports a wide range of sample rates from 8 kHz to 96 kHz
Automatic sample rate detection
Can operate using 64 × fS BCLK as the MCLK source
2.5 V to 5.5 V speaker supply voltage (PVDD)
1.62 V to 3.6 V digital supply voltage (DVDD)
Pop-and-click suppression
Short-circuit and thermal protection with programmable
autorecovery
The SSM2518 is a digital input, Class-D power amplifier that com-
bines 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 dissi-
pation, and the highest audio efficiency without sacrificing
audio quality.
Smart power-down when no input signal is detected
Power-on reset
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.
Low power modes for performance/power trade-offs
User selectable ultralow EMI emission mode
Programmable dynamic range compression (DRC) with
noise gate, expander, compressor, and limiter
Available in two packages
16-bump, 2.2 mm × 2.2 mm, 0.5 mm pitch WLCSP
20-lead, 4.0 mm × 4.0 mm LFCSP
Additional features include a soft digital volume control, de-
emphasis, and a programmable digital dynamic range
compressor.
APPLICATIONS
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.
Mobile phones
Portable media players
Laptop PCs
Wireless speakers
Portable gaming
Small LCD televisions
Navigation systems
Rev. A
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