SSM2305-EVALZ Analog Devices Inc, SSM2305-EVALZ Datasheet - Page 11

• Manufacturer Part Number: SSM2305-EVALZ
• Description: BOARD EVAL FOR SSM2305 LFCSP
• Manufacturer: Analog Devices Inc

Specifications of SSM2305-EVALZ

• Amplifier Type: Class D
• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 2.8W x 1 @ 4 Ohm
• Voltage - Supply: 2.2 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: SSM2305
• Silicon Manufacturer: Analog Devices
• Application Sub Type: Audio Power Amplifier - Class D
• Kit Application Type: Amplifier
• Silicon Core Number: SSM2305
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
OVERVIEW
The SSM2305 mono Class-D audio amplifier features a filterless
modulation scheme that greatly reduces the external components
count that, in turn, conserves board space, thereby reducing
systems cost. The SSM2305 does not require an output filter,
relying instead 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 SSM2305 uses Σ-Δ modulation to determine the
switching pattern of the output devices, resulting in a number of
AUDIO IN+
AUDIO IN+
EXTERNAL GAIN SETTINGS = 296kΩ/(37kΩ + R
AUDIO IN–
EXTERNAL GAIN SETTINGS = 296kΩ/(37kΩ + R
*INPUT CAPACITORS ARE OPTIONAL IF INPUT DC COMMON-MODE
SHUTDOWN
SHUTDOWN
VOLTAGE IS APPROXIMATELY V
Figure 33. Single-Ended Input Configuration, User-Adjustable Gain
47nF*
47nF*
47nF
47nF
Figure 32. Differential Input Configuration, User-Adjustable Gain
R
R
R
R
EXT
EXT
EXT
EXT
IN+
IN–
SD
IN+
IN–
SD
SSM2305
SSM2305
37kΩ
37kΩ
37kΩ
37kΩ
Rev. A | Page 11 of 16
DD
/2.
BIAS
BIAS
MODULATOR
MODULATOR
EXT
EXT
10µF
10µF
296kΩ
296kΩ
296kΩ
296kΩ
)
)
(Σ-Δ)
(Σ-Δ)
OSCILLATOR
OSCILLATOR
INTERNAL
INTERNAL
important benefits. 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 emission that might otherwise be radiated
by speakers and long cable traces. Due to the inherent spread-
spectrum nature of Σ-Δ modulation, the need for oscillator
synchronization is eliminated for designs incorporating multiple
SSM2305 amplifiers.
The SSM2305 also offers protection circuits for overcurrent and
temperature protection.
0.1µF
0.1µF
DRIVER
DRIVER
FET
FET
GND
GND
SUPPRESSION
SUPPRESSION
VDD
POP/CLICK
VDD
POP/CLICK
OUT+
OUT–
OUT+
OUT–
VBATT
2.5V TO 5.5V
VBATT
2.5V TO 5.5V
SSM2305