MAX98090AETL+ Maxim Integrated, MAX98090AETL+ Datasheet - Page 163

• Manufacturer Part Number: MAX98090AETL+
• Description: Interface - CODECs 5V 130mW Stereo Headphone Amp
• Manufacturer: Maxim Integrated

Specifications of MAX98090AETL+

• Rohs: yes

MAX98090
Figure 57. PCB Breakout Routing Example for WLP Package
Supply Bypassing, Layout, and Grounding
Proper layout and grounding are essential for optimum
performance. When designing a PCB layout, partition
the circuitry so that the analog sections of the device are
separated from the digital sections. This ensures that the
analog audio traces are not routed near digital traces.
Use a large continuous ground plane on a dedicated
layer of the PCB to minimize loop areas. Connect AGND,
DGND, and HPGND directly to the ground plane using the
shortest trace length possible. Proper grounding improves
audio performance, minimizes crosstalk between chan-
nels, and prevents any digital noise from coupling into the
analog audio signals.
Ground the bypass capacitors on MICBIAS, BIAS and
REF directly to the ground plane with minimum trace
length. Also be sure to minimize the path length to AGND,
and bypass AVDD directly to AGND. Connect all digital
I/O termination to the ground plane with minimum path
length to DGND, and bypass DVDD and DVDDIO directly
to DGND.
Place the capacitor between C1P and C1N as close as
possible to the device to minimize trace length from C1P
to C1N. Inductance and resistance added between C1P
and C1N reduce the output power of the headphone
amplifier. Bypass HPVDD, CPVDD and CPVSS with
capacitors located close to the pin with short trace lengths
to HPGND. Close decoupling of CPVDD and CPVSS
minimizes supply ripple and maximizes output power from
the headphone amplifier.
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LAYER 1
LAYER 2
HPSNS senses ground noise on the headphone jack and
adds the same noise to the output audio signal, thereby
making the output (headphone output, ground) noise free.
Connect HPSNS to the headphone jack shield to ensure
accurate pickup of headphone ground noise.
Bypass SPK_VDD to SPK_GND with the shortest trace
length possible and connect SPKLP, SPKLN, SPKRP, and
SPKRN to the stereo speakers using the shortest traces
possible. If filter components are used on the speaker
outputs, be sure to locate them as close as possible to the
device to ensure maximum effectiveness.
Route microphone signals from the microphone to the
device as a differential pair, ensuring that the positive
and negative signals follow the same path as closely
as possible with equal trace length. When using single-
ended microphones or other single-ended audio sources,
ground the negative microphone input as near to the
audio source as possible and then treat the positive and
negative traces as differential pairs.
An evaluation kit (EV Kit) is available to provide an exam-
ple layout. The EV Kit allows quick setup of the device
and includes easy-to-use software allowing all internal
registers to be controlled.
Recommended PCB Routing
The IC uses a 49-bump WLP package. Figure 57 pro-
vides an example of how to connect to all active bumps
using 3 layers of the PCB. To ensure uninter rupted
ground returns, use layer 2 as a connecting or dog-bone
layer between layer 1 and layer 3, and flood the remaining
area with a copper ground plane.
Ultra-Low Power Stereo Audio Codec
LAYER 3
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