SSM2380CBZ-REEL Analog Devices Inc, SSM2380CBZ-REEL Datasheet - Page 14

• Manufacturer Part Number: SSM2380CBZ-REEL
• Description: Stereo ClassD Amplifier I2C Gain Control
• Manufacturer: Analog Devices Inc
• Type: Class Dr

Specifications of SSM2380CBZ-REEL

• Output Type: 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 3.2W x 2 @ 4 Ohm
• Voltage - Supply: 2.5 V ~ 5.5 V
• Features: Depop, Differential Inputs, I²C, Mute, Short-Circuit and Thermal Protection
• Mounting Type: Surface Mount
• Package / Case: 16-UFBGA, WLCSP
• Operational Class: Class-D
• Audio Amplifier Output Configuration: 2-Channel Stereo
• Audio Amplifier Function: Speaker
• Single Supply Voltage (typ): 3/5V
• Power Supply Requirement: Single
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 85dB
• Single Supply Voltage (min): 2.5V
• Single Supply Voltage (max): 5.5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 16
• Package Type: WLCSP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SSM2380
THEORY OF OPERATION
OVERVIEW
The SSM2380 stereo, Class-D audio amplifier features a filterless
modulation scheme that greatly reduces the external component
count, conserving board space and, thus, reducing system cost.
The SSM2380 does not require an output filter but, instead, relies
on the inherent inductance of the speaker coil and the natural
filtering of the speaker and human ear to fully recover the audio
component of the square wave output.
Most Class-D amplifiers use some variation of pulse-width
modulation (PWM), but the SSM2380 uses Σ-Δ modulation to
determine the switching pattern of the output devices, resulting
in a number of important benefits.
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•
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Using the I
be selected from 1 dB to 24 dB (plus mute) in 47 steps with no
external components and fixed input impedance. Other features
accessed from the I
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The SSM2380 also offers protection circuits for overcurrent and
overtemperature protection.
POP-AND-CLICK SUPPRESSION
Voltage transients at the output of audio amplifiers can occur
when shutdown is activated or deactivated. Voltage transients
as low as 10 mV can be heard as an audio pop in the speaker.
Clicks and pops can also be classified as undesirable audible
transients generated by the amplifier system and, therefore, as
not coming from the system input signal. Such transients may
be generated when the amplifier system changes its operating
mode. For example, the following may be sources of audible
transients: system power-up and power-down, mute and
unmute, input source change, and sample rate change.
Σ-Δ modulators do not produce a sharp peak with many
harmonics in the AM frequency band, as pulse-width
modulators often do.
Σ-Δ modulation provides the benefits of reducing the
amplitude of spectral components at high frequencies,
that is, reducing EMI emissions that might otherwise
be radiated by speakers and long cable traces.
The SSM2380 does not require external EMI filtering for
twisted speaker cable lengths shorter than 10 cm. If longer
speaker cables are used, the SSM2380 has an emission sup-
pression mode that allows significantly longer speaker cable.
Due to the inherent spread-spectrum nature of Σ-Δ modu-
lation, the need for modulator synchronization is eliminated
for designs that incorporate multiple SSM2380 amplifiers.
Independent left/right channel shutdown
Variable ultralow EMI emission control mode
Automatic level control (ALC) for high quality speaker
protection
Stereo-to-mono mixing operation
2
C control interface, the gain of the SSM2380 can
2
C interface include the following:
Rev. A | Page 14 of 32
The SSM2380 has a pop-and-click suppression architecture that
reduces these output transients, resulting in noiseless activation
and deactivation.
OUTPUT MODULATION DESCRIPTION
The SSM2380 uses three-level, Σ-Δ output modulation. Each
output can swing from GND to V
no input signal is present, the output differential voltage is 0 V
because there is no need to generate a pulse. In a real-world
situation, noise sources are always present.
Due to the constant presence of noise, a differential pulse is
generated, when required, in response to this stimulus. A small
amount of current flows into the inductive load when the differ-
ential pulse is generated.
Most of the time, however, the output differential voltage is 0 V,
due to the Analog Devices, Inc., three-level, Σ-Δ output modu-
lation. This feature ensures that the current flowing through the
inductive load is small.
When the user wants to send an input signal, an output pulse
(OUTx+ and OUTx−) is generated to follow the input voltage.
The differential pulse density (V
input signal level. Figure 35 depicts three-level, Σ-Δ output
modulation with and without input stimulus.
OUT+
OUT–
OUT+
OUT–
OUT+
OUT–
V
V
V
OUT
OUT
OUT
OUTPUT = 0V
OUTPUT > 0V
OUTPUT < 0V
Figure 35. Three-Level, Σ-Δ Output Modulation
With and Without Input Stimulus
OUT
DD
) is increased by raising the
and vice versa. Ideally, when
+5V
0V
+5V
0V
+5V
0V
–5V
+5V
0V
+5V
0V
+5V
0V
+5V
0V
+5V
0V
0V
–5V