SSM2375 Datasheet, PDF (1/13 Pages) Analog Devices – Filterless High Efficiency Mono 3 W Class-D Audio Amplifier

Preliminary Technical Data
Filterless High Efficiency
Mono 3 W Class-D Audio Amplifier
SSM2375
FEATURES
Filterless Class-D
r with spread-spectrum Σ-∆
modulation
3 W into 3 Ω load and 1.4 W into 8 Ω load at 5.0 V supply with
<1% total harmonic distortion (THD)
93%
cy at 5.0 V, 1.4 W into 8 Ω speaker
>100 dB signal-to-noise ratio (SNR)
High PSRR @ 217 Hz: 80dB
Flexible gain adjustment pin: 0dB to 12dB in 3dB steps
Fixed Input Impedance, 80kΩ
User-selectable ultralow EMI emissions mode
Single-supply operation from 2.5 V to 5.5 V
20 nA shutdown current
Short-circuit and thermal protection with auto recovery
Available in 9-ball, 1.5 mm × 1.5 mm WLCSP
Pop-and-click suppression
APPLICATIONS
Mobile phones
MP3 players
Portable electronics
GENERAL DESCRIPTION
SM2375 is a fully integrated, high e ciency Class-D
audio ampli er. It is designed to maximize performance for
mobile phone applications. e 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 an 3 Ω load
from a 5.0 V supply.
SM2375 features a high e ciency, low noise modulation
scheme that requires no external LC output lt
modulation operates with high e ciency even at low output
power. It operates with 93% e ciency at 1.4 W into 8 Ω or 85%
e ciency at 3 W into 3 Ω from a 5.0 V supply and has an SNR
of >100 dB.
Spread-spectrum pulse density modulation (PDM) is used to
provide lower EMI-radiated emissions compared with other
Class-D architectures. e inherent randomized nature of
spread-spectrum PDM eliminates clock intermodulation
(beating e ect) of several ampli ers in close proximity.
SM2375 includes an optional modulation select pin
(ultralow EMI emission mode) that signi cantly reduces the
radiated emissions at the Class-D outputs, particularly above 100
MHz and can pass FCC Class B radiated emissions testing with
50cm unshielded speaker cable without any external ltering.
evice also includes a highly exible gain select pin that
only requires one series resistor in order to select between 0dB,
3dB, 6dB, 9dB, or 12dB. e bene t of this is to improve gain
matching between multiple SSM2375 devices within a single
application as compared to using external resistors to set gain.
SM2375 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.
device also includes pop-and-click suppression circuitry.
minimizes voltage glitches at the output during turn-on and
turn-o , reducing audible noise on activation and deactivation.
Other included features to simplify system level integration of the
SSM2375 are input low pass ltering to suppress out of band DAC
noise interference to the PDM modulator and xed input
impedance to simplify component selection across multiple
platform production builds.
SM2375 is speci ed 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 halogen-free 9-ball,
1.5 mm × 1.5 mm wafer level chip scale package (WLCSP).
Rev. PrC
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