Datasheet

MAX98400B Evaluation Kit
Evaluates: MAX98400B
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Table 1. Jumper Descriptions (U1)
*Default position.
Filterless Output (U1)
The EV kit’s filterless outputs (SPKL1+/SPKL1- and
SPKR1+/SPKR1-) can be connected directly to a pair of
speaker loads without any filtering.
Output Filtering Requirements (U1)
The device can pass CE EN55022B regulations with only
ferrite-bead filters, especially when speaker-wire lengths
are less than or equal to 1m. To install the ferrite-bead
filters, first remove the 0I resistors (R111–R114). Next,
replace resistors R111–R114 with ferrite beads listed
in Table 3 (provided with the EV kit), and install filter
capacitors on the C111–C114 pads. The speaker wire
should be connected to the L1+/L1- and R1+/R1- test
points. Although component selection for the output filter
is dependent on speaker-wire length, the components in
Table 3 are provided with the EV kit as a starting point.
Final component selection should be determined during
EMC testing. Contact the factory, if required. Note that
an inductive load is required at this terminal. If using an
8I power resistor, add a 68FH series inductor. If using a
4I power resistor, add a 33FH series inductor.
Filtered Output (U2)
Audio analyzers typically cannot accept pulse-width
modulated (PWM) signals at their inputs. Therefore,
the EV kit features a pair of lowpass filters at each of
the outputs to ease evaluation. Use the filtering output
posts (FOUTL2+/FOUTL2- and FOUTR2+/FOUTR2-) to
connect the filtered PWM outputs to the audio analyzer.
The default lowpass filters at the EV kit outputs are opti-
mized for a pair of 8I power resistors or 8I speakers.
Thermal Foldback
As shipped from the factory, the thermal-foldback
feature is enabled (TEMP_1 and TEMP_2 jumpers open).
To disable thermal foldback, install a shunt across the
TEMP_1 or TEMP_2 jumper. Refer to the MAX98400A/
MAX98400B IC data sheet for information on selecting
this resistor value.
Limiter
As shipped from the factory, the limiter-threshold control
is disabled. To enable the limiter in PVDD tracking mode,
move the LIM_1 or LIM_2 shunt to the 2-3 position. To
enable the limiter in programmable mode, leave the
LIM_1 or LIM_2 jumper open and select appropriate val-
ues for R103, R104, and R105 or R203, R204, and R205.
Refer to the MAX98400A/MAX98400B IC data sheet for
information on selecting these component values.
JUMPER
SHUNT
POSITION
DESCRIPTION
SHDN_1
1-2*
Normal operation; U1 SHDN =
DVDD (external logic-high)
Open
Shutdown; U1 SHDN = GND
TEMP_1
Open*
Thermal foldback enabled; U1
TEMPLOCK = unconnected
1-2
Thermal foldback disabled; U1
TEMPLOCK = GND
LIM_1
1-2*
Limiter disabled; U1 LIM_TH =
VS1
2-3
Limiter enabled in PVDD tracking
mode; U1 LIM_TH = GND
Open
Limiter programmable mode; U1
LIM_TH is determined by R103,
R104, and R105
JUMPER
SHUNT
POSITION
DESCRIPTION
JU104
1-2*
Single-ended input mode; U1
INL- = GND
Open
Differential input mode; U1 INL-
is not connected to GND
JU105
1-2*
Single-ended input mode; U1
INR- = GND
Open
Differential input mode; U1 INR-
is not connected to GND
GAIN1_1
1-2 U1 G1 = VS1
2-3* U1 G1 = GND
Open U1 G1 is not driven
GAIN2_1
1-2 U1 G2 = VS1
2-3 U1 G2 = GND
Open* U1 G2 is not driven