EVAL-SSM2537Z Analog Devices, EVAL-SSM2537Z Datasheet - Page 15

• Manufacturer Part Number: EVAL-SSM2537Z
• Description: Audio IC Development Tools SSM2537 EVALUATION BOARD
• Manufacturer: Analog Devices
• Type: Class D Audio Amplifiersr
• Series: SSM2537r

Specifications of EVAL-SSM2537Z

• Rohs: yes
• Product: Evaluation Boards
• Tool Is For Evaluation Of: SSM2537
• Operating Supply Voltage: 2.5 V to 5.5 V
• Factory Pack Quantity: 1

Data Sheet
APPLICATIONS INFORMATION
LAYOUT
As output power increases, take care to lay out PCB traces and
wires properly among the amplifier, load, and power supply.
A good practice is to use short, wide PCB tracks to decrease
voltage drops and minimize inductance. Avoid ground loops
where possible to minimize common-mode current associated
with separate paths to ground. Ensure that track widths are
at least 200 mil per inch of track length for the lowest DCR,
and use 1 oz or 2 oz copper PCB traces to further reduce IR
drops and inductance. A poor layout increases voltage drops,
consequently affecting efficiency. Use large traces for the power
supply inputs and amplifier outputs to minimize losses due to
parasitic trace resistance.
Proper grounding helps to improve audio performance,
minimize crosstalk between channels, and prevent switching
noise from coupling into the audio signal. To maintain high
output swing and high peak output power, the PCB traces that
connect the output pins to the load, as well as the PCB traces
to the supply pins, should be as wide as possible to maintain
the minimum trace resistances. It is also recommended that
a large ground plane be used for minimum impedances.
In addition, good PCB layout isolates critical analog paths from
sources of high interference. Separate high frequency circuits
(analog and digital) from low frequency circuits.
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Properly designed multilayer PCBs can reduce EMI emissions
and increase immunity to the RF field by a factor of 10 or more,
compared with double-sided boards. A multilayer board allows
a complete layer to be used for the ground plane, whereas the
ground plane side of a double-sided board is often disrupted by
signal crossover.
POWER SUPPLY DECOUPLING
To ensure high efficiency, low total harmonic distortion (THD),
and high PSRR, proper power supply decoupling is necessary.
Noise transients on the power supply lines are short-duration
voltage spikes. These spikes can contain frequency components
that extend into the hundreds of megahertz.
The power supply input must be decoupled with a good quality,
low ESL, low ESR capacitor, with a minimum value of 4.7 µF.
This capacitor bypasses low frequency noises to the ground
plane. For high frequency transient noises, use a 0.1 µF capac-
itor as close as possible to the PVDD and VDD pins of the
device. Placing the decoupling capacitors as close as possible
to the
SSM2537
helps to maintain efficient performance.
SSM2537