MAX98356EWL+ Maxim Integrated, MAX98356EWL+ Datasheet - Page 19

• Manufacturer Part Number: MAX98356EWL+
• Description: Audio Amplifiers PCM Input Class D Audio Power Amp
• Manufacturer: Maxim Integrated

Specifications of MAX98356EWL+

• Rohs: yes
• Product: Class-D
• Output Power: 3.2 W
• Thd Plus Noise: 0.013 %
• Operating Supply Voltage: 2.5 V to 5.5 V
• Supply Current: 1.7 mA
• Maximum Power Dissipation: 1096 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: WLP-9
• Minimum Operating Temperature: - 40 C

Traditional Class D amplifiers require an output filter
to recover the audio signal from the amplifier’s output.
The filter adds cost, size, and decreases efficiency
and THD+N performance. The IC’s filterless modulation
scheme does not require an output filter. The device relies
on the inherent inductance of the speaker coil and the
natural filtering of both the speaker and the human ear to
recover the audio component of the square-wave output.
Because the switching frequency of the IC is well beyond
the bandwidth of most speakers, voice coil movement
due to the switching frequency is very small. Use a
speaker with a series inductance > 10FH. Typical 8I
speakers exhibit series inductances in the 20FH to
100FH range.
V
including the speaker amplifier. Bypass V
and 10FF capacitor to GND. Some applications might
require only the 10FF bypass capacitor, making it pos-
sible to operate with a single external component. Apply
additional bulk capacitance at the IC if long input traces
between V
Proper layout and grounding are essential for optimum
performance. Good grounding improves audio perfor-
mance and prevents switching noise from coupling into
the audio signal.
Use wide, low-resistance output traces. As load imped-
ance decreases, the current drawn from the device
outputs increases. At higher current, the resistance of
the output traces decreases the power delivered to the
load. For example, if 2W is delivered from the speaker
output to a 4I load through 100mI of total speaker
trace, 1.904W is being delivered to the speaker. If power
is delivered through 10mI of total speaker trace, 1.951W
is being delivered to the speaker. Wide output, supply,
and ground traces also improve the power dissipation of
the IC.
The IC is inherently designed for excellent RF immunity.
For best performance, add ground fills around all signal
traces on top or bottom PCB planes.
DD
, which ranges from 2.5V to 5.5V, powers the IC,
DD
and the power source are used.
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Filterless Class D Operation
PDM Input Class D Audio Power Amplifier
Layout and Grounding
Power-Supply Input
DD
with a 0.1FF
For the latest application details on WLP construction,
dimensions, tape carrier information, PCB techniques,
bump-pad layout, and recommended reflow temperature
profile, as well as the latest information on reliability testing
results, refer to the Application Note 1891: Wafer-Level
Packaging (WLP) and Its Applications.
the dimensions of the WLP balls used on the IC.
Figure 10. (Left + Right)/2 Operation with 6dB Gain
Figure 11. MAX98356 WLP Ball Dimensions
PDM DATA OUT
PDM CLOCK
CODEC
GPIO*
(300kI)**
R
LARGE
*LEFT AND RIGHT CHANNELS SUMMED WHEN GPIO IS HIGH.
**300kI ASSUMES V
THE MAX98356 IS SHUTDOWN WHEN GPIO IS LOW.
PDM_DATA
WLP Applications Information
SD_MODE
PDM_CLK
10µF
A1
C1
B1
0.24mm
0.21mm
B2
GPIO
0.1µF
MAX98356
GAIN
C2, C3
= 1.8V.
MAX98356
GND
2.5V TO 5.5V
A2
V
A3
B3
DD
Figure 11
OUTP
OUTN
shows