Datasheet

Maxim Integrated │ 4
www.maximintegrated.com
Evaluates: MAX98357A/MAX98357B
(WLP)
MAX98357 Development Board/
Evaluation System (WLP)
External/Internal VDDIO (+1.8V to +3.3V)
On the DEV board, a logic voltage from a control interface
is needed for proper selection of the stereo input channel
through SD_MODE. This voltage can be applied exter-
nally at the VDDIO test point or it can be provided from
circuitry on the AUDINT001 board. See Table 5 for JU4
jumper selection.
Other logic voltages can be used other than +3.3V. If you
want to use other logic voltages, resistors R3 and R4
must be adjusted. Refer to the SD_MODE and Shutdown
Operation section in the MAX98357 IC data sheet for
more information.
VDD Input Supply (+2.5V to +5.5V)
The device can accept an input supply from +2.5V to
+5.5V. This voltage can be applied externally at the
VDD and GND PCB pads, or it can be provided from the
AUDINT001 board. See Table 6 for JU6 jumper selection.
Audio Interface Board (AUDINT001 Board)
The AUDINT001 board provides USB-to-I
2
S data conver-
sion, as well as DC regulators that can be used to power
the devices. The USB-to-I
2
S converter on the AUDINT001
board allows for any computer to become an I
2
S digital
audio source. On the AUDINT001 board, set SW1 to
“demo” and set the I
2
S switch to connected to source
audio by USB. This allows for a quick evaluation from a
single USB connection. Using the AUDINT001 board as
a power supply for high-power evaluation is not recom-
mended as the input current is limited. For high-power
evaluation, use an external supply connected to VIN.
Driving I
2
S Directly
To drive I
2
S directly, apply signals at the BCLK, LRCLK,
and SDIN test points, or on the J3 header, or between J3
pins 1-2 at the appropriate locations (signal and ground
are labeled on the board).
Evaluating the MAX98357B
The MAX98357 DEV board comes with a MAX98357A
populated on the board, but can also be used to evaluate
the MAX98357B. To evaluate the MAX98357B, carefully
remove the MAX98357A (U1) device from the board and
replace with the MAX98357BEWL+. No other component
changes are required.
Table 5. JU4 Jumper Selection (VDDIO) Table 6. JU6 Jumper Selection (VDD)
*Default position. *Default position.
SHUNT
POSITION
LOGIC VOLTAGE (VDDIO)
1-2*
3.3V supplied by the AUDINT001 board
connected to J1 header.
2-3
User-supplied external power supply applied
at the VDDIO test point.
SHUNT
POSITION
INPUT VOLTAGE (VDD)
1-2*
VDD supplied from the AUDINT001 board
connected to the J1 header.
2-3
User-supplied external power supply applied
at the VIN PCB pad.