max98088 Maxim Integrated Products, Inc., max98088 Datasheet - Page 118

• Manufacturer Part Number: max98088
• Description: Stereo Audio Codec With Flexsound Technology
• Manufacturer: Maxim Integrated Products, Inc.

Table 38. Registers That Are Sensitive to Changes During Operation
Stereo Audio Codec
with FLEXSOUND Technology
Many configuration options in the ICs can be made
while the devices are operating, however, some regis-
ters should only be adjusted when the corresponding
audio path is disabled. Table 38 lists the registers that
are sensitive during operation. Either disable the cor-
responding audio path or set SHDN = 0 while changing
these registers.
In applications where speaker leads exceed 20mm,
additional EMI suppression can be achieved by using a
filter constructed from a ferrite bead and a capacitor to
ground (Figure 41). Use a ferrite bead with low DC resis-
tance, high-frequency (> 600MHz) impedance between
100I and 600I, and rated for at least 1A. The capacitor
value varies based on the ferrite bead chosen and the
actual speaker lead length. Select a capacitor less than
1nF based on EMI performance.
An input capacitor, C
impedance of the IC line inputs forms a highpass filter
Figure 41. Optional Class D Ferrite Bead Filter
118
0x10 to 0x13, 0x19 to 0x1B
0x14 to 0x17, 0x1C to 0x1F
IN
0x25 to 0x2D
0x52 to 0xC9
REGISTER
0x18, 0x20
, in conjunction with the input
Optional Ferrite Bead Filter
Component Selection
Input Capacitor
MAX98088
SPK_N
SPK_P
that removes the DC bias from an incoming analog
signal. The AC coupling capacitor allows the amplifier
to automatically bias the signal to an optimum DC level.
Assuming zero-source impedance, the -3dB point of the
highpass filter is given by:
Choose C
quency of interest. For best audio quality use capacitors
whose dielectrics have low-voltage coefficients, such as
tantalum or aluminum electrolytic. Capacitors with high-
voltage coefficients, such as ceramics, may result in
increased distortion at low frequencies.
Use capacitors with an ESR less than 100mI for optimum
performance. Low-ESR ceramic capacitors minimize the
output resistance of the charge pump. Most surface-
mount ceramic capacitors satisfy the ESR requirement.
For best performance over the extended temperature
range, select capacitors with an X7R dielectric.
Digital Signal Processing Coefficients
IN
Digital Audio Interface Configuration
so that f
Clock Control Registers
Digital Passband Filters
f
-3dB
DESCRIPTION
Charge-Pump Capacitor Selection
Analog Mixers
-3dB
=
2 R C
is well below the lowest fre-
π
IN IN
1