Rainbow Electronics MAX98088 - Manual (Page 99)

Stereo Audio Codec
with FLEXSOUND Technology
MAX98088
99
Figure 27. Speaker Amplifier Signal Processing Block Diagram
The transfer function for the user-programmable biquad is:
-1 -2
0 1 2
-1 -2
1 2
b b z b z
H(z)
1 a z a z
+ +
=
+ +
The coefficients b 0 , b 1 , b 2 , a 1 , and a 2 are sample
rate dependent and stored in registers 0xB4 through
0xC7. Store b
0
, b
1
, and b
2
as positive numbers. Store
a 1 and a 2 as negated two’s complement numbers.
Separate filters can be stored for the DAI1 and DAI2
playback paths.
The MAX98088/MAX98089 EV kit software includes a
graphic interface for generating the user-programmable
biquad coefficients.
Note: Only change the excursion limiter settings when
the signal path is disabled to prevent undesired artifacts.
EQ1EN EQ2EN
DVEQ1:
0dB TO -15dB
DV1G:
0/6/12/18dB
DV2:
0dB TO -15dB
DCB2
5-BAND
PARAMETRIC
EQ
5-BAND
PARAMETRIC
EQ
DVEQ2:
0dB TO -15dB
MULTI BAND ALC
EXCURSION LIMITER
DV1:
0dB TO -15dB
MODE1
DVFLT
DALEN
MIXDAR
DACL
DAREN
DACR
+
AUDIO/
FILTERS
AUDIO/
VOICE
FILTERS
MIX
MIXDAL
MIX
MIXSPR
MIX
MIXSPL
MIX
SPKLP
SPKLN
SPVOLL:
+8dB TO -62dB SPKLVDD
SPKLGND
SPKRVDD
SPKRP
SPKRN
SPLEN
SPREN
POWER/
DISTORTION LIMITER
SPVOLR:
+8dB TO -62dB SPKRGND
+6dB
+6dB