Datasheet

MAX9867 Evaluation Kit
Evaluates: MAX9867
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Detailed Description of Hardware
The MAX9867 EV kit is a complete digital audio evalu-
ation system for the MAX9867 low-power, stereo audio
codec. The EV kit provides translation between the
digital audio signals and optical S/PDIF signals to allow
easy connection with consumer electronics devices. See
Table 1 for a description of all EV kit jumper configura-
tions.
Clocking
On-Board Clock
The EV kit has one 12.288MHz and one 13MHz clock
oscillator on the board to provide flexible master-clock
selections for the MAX9867.
Recovered Clock
When the S/PDIF IN has a digital audio input and the
S/PDIF transceiver is in operation, the recovered clock
from the S/PDIF transceiver can be used as the master
clock for the MAX9867.
External Clocks
Connect an external clock source to jumper JU12 pin 2
to drive the MAX9867 MCLK pin without using the on-
board oscillator. The user must type in the correct clock
frequency in the MCLK Frequency edit box.
Jack Detection and
DC-Voltage Measurement
The MAX9867 has a JACKSNS/AUX pin that can be con-
figured to either detect the presence/absence of a jack
or accurately measure a DC voltage.
To measure a DC voltage, place a shunt on jumper JU7
and apply the DC voltage on the AUX pad. The on-board
resistor network (R5, R6) can be used to adjust the input
voltage ranges.
To detect the presence or absence of a jack, remove the
shunt on jumper JU7 and connect the JACKSNS pad to
a proper jack pin. Refer to the MAX9867 IC data sheet
for the details of jack-detection functionality.
Microphone Inputs
The MAX9867 features stereo differential microphone
inputs that can be connected to either analog or digital
microphones.
MICRP and MICRN pins can only connect to an analog
microphone. Place shunts on jumpers JU1 and JU3 to
use the MAX9867 MICBIAS for microphone biasing.
Place a shunt on jumper JU2 to connect MICRN to GND
for single-ended microphone input.
MICLP/DIGMICDATA and MICLN/DIGMICCLK pins can
connect either to an analog microphone or a digital
microphone, but not at the same time. For analog
microphone input, remove the shunts on jumpers JU8
and JU9. Place shunts on jumpers JU4 and JU6 to use
the MAX9867 MICBIAS for microphone biasing. Place
a shunt on jumper JU2 to connect MICLN to GND for
single-ended microphone input. For digital microphone
input, place shunts on JU8 and JU9 and remove con-
nections on the MICLP and MICLN pads. There are two
digital microphones on the EV kit board.
Headphone Outputs
There are two headphone jacks on the EV kit board.
Use J4 for differential or capacitorless output configura-
tion. Remove the shunts on jumpers JU10 and JU11.
Use J5 for single-ended output configuration. Remove
the shunts on jumpers JU10 and JU11 for fast turn-on
mode. Place the shunts on JU10 and JU11 for clickless
mode.