MAX13301 Datasheet, PDF (24/37 Pages) Maxim Integrated Products – 4-Channel, Automotive Class D Audio Amplifier Feedback After the Filter

4-Channel, Automotive Class D Audio Amplifier
Table 18. Mapping Register
BIT #
NAME
POR
7
COMP2
0
6
COMP1
1
5
COMP0
0
MAP
4
OTWM
0
3
LCTM
0
2
MCLP
0
1
OTM
0
0
FLTM
0
Table 19. Mapping Register Bit Description
BIT
BIT DESCRIPTION
Integrator and Triangle-Wave Capacitor Trim. A smaller integrator capacitor pushes noise out of the audio
band yielding the lowest noise. If distortion rises at high output powers, lower switching frequencies, or
higher PVDD voltages then use a larger capacitor setting. See Table 20 for choosing minimum capacitor
settings based on PVDD and the switching frequency. Larger capacitor values can be used.
COMP[2:0]
OTWM
If all 4 channels of the amplifier are used to drive subwoofers, the capacitor settings can be relaxed
because a smaller capacitor setting helps to eliminate high-frequency noise (greater than 10kHz). Systems
with multiple tweeters benefit the most from proper COMP[2:0] selection. Lower switching frequencies are
possible when this high-frequency noise is not a concern as with systems that lack tweeters.
000 = 43pF
001 = 37pF
010 = 31pF
011 = 25pF
100 = 18pF
101 = Reserved
110 = Reserved
111 = Reserved
Overtemperature Warning Mapping Bit
0 = STAT.OTW (overtemperature warning bit) is unmapped to the FLT_OT open-drain output.
1 = STAT.OTW is mapped to FLT_OT when MAP.OTM = 1.
LCTM
Low-Current Threshold Mapping Bit. The current thresholds used in tweeter and shorted load diagnostics
are lower than the current limit. When the threshold is exceeded in running either diagnostic,
OSTAT1.LOAD[3:0] (load indicator bit) asserts. Hardware indication is also possible by using LCTM to map
OSTAT1.LOAD[3:0] to the CL0 and MUTE_CL1 outputs.
0 = OSTAT1.LOAD[3:0] (load indicator bit used for tweeter and shorted load diagnostics) is unmapped to
the CL0 and MUTE_CL1 outputs.
1 = OSTAT1.LOAD[3:0] is mapped to the CL0 and MUTE_CL1 outputs. Use this setting only when running
tweeter or shorted load diagnostic.
MCLP
OTM
Clip Output Mapping. MCLP determines which open-drain outputs (CL0 and MUTE_CL1) are used to indi-
cate clipping on an audio output. CL0 is always used as a clip indicator, while MUTE_CL1 is configurable
as a clip indicator output or as a mute input.
0 = CL0 provides clip indication for all audio outputs; MUTE_CL1 is configured as a mute input.
1 = CL0 provides clip indication for audio outputs 0 and 1; MUTE_CL1 is configured as a clip indicator out-
put for audio outputs 2 and 3.
Overtemperature Shutdown Map
0 = STAT.OT (overtemperature shutdown bit) is unmapped to the open-drain FLT_OT output.
1 = STAT.OT is mapped to the FLT_OT output.
FLTM
Fault Mapping Bit
0 = Faults are unmapped to the open-drain FLT_OT output.
1 = Any fault condition (as indicated by the status bits OV, UV, OC) causes FLT_OT to assert low.
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