Datasheet

MAX98089 Evaluation Kit (TQFN)
Evaluates: MAX98089 (TQFN)
_______________________________________________________________________________________ 9
S/PDIF Transceiver
The CS8427 S/PDIF transceiver serves as a format con-
verter between I
2
S and S/PDIF. Use this device to send
and receive digital audio over the optical connectors
(J5, J6).
When receiving S/PDIF data, the CS8427 outputs a
recovered master clock that is exactly 256 x f
S
, where
f
S
is the sample rate. This clock signal can be used to
clock the IC.
When transmitting S/PDIF data, the CS8427 requires a
master-clock input. If S/PDIF data is also being received,
the CS8427 uses this data to generate its own master
clock. If S/PDIF data is not being received, then the
CS8427 generates a master clock based on the LRCLK
signal being output by the IC. For proper transmit-only
operation, the IC must be configured in master mode.
USB Audio
The PCM2707 USB DAC generates I
2
S audio data from
a USB connection to the PC. The PCM2707 supports
standard class drivers that are included in most operat-
ing systems. As a result, no drivers are required for this
device. The PCM2707 appears as a sound card in the
PC and allows audio playback from the PC through the
IC. The PCM2707 also generates a master-clock signal
that can be used to clock the IC. The clock signal is 256
x f
S
.
Digital Microphone
The EV kit includes an on-board digital microphone
to demonstrate the digital microphone input. Install
shunts on jumpers JU27 and JU32 to enable the
microphone. When using the digital microphone, the
MIC1 analog microphone input cannot be used. If a
second digital microphone is added, then MIC2 is also
unavailable.
Jumper Selection
The EV kit includes 20 jumpers to adjust various hard-
ware configuration options. Table 1 describes all the
jumpers available on the EV kit.
Table 1. Jumper Selection
JUMPER SHUNT POSITION DESCRIPTION
JU12 — See Table 2
JU13 — See Table 3
JU14
1-2* Connects 1.8V to DVDD
Open Allows external powering of DVDD
JU15
1-2* Connects 1.8V to AVDD
Open Allows external powering of AVDD
JU16
1-2* Connects 1.8V to PVDD
Open Allows external powering of PVDD
JU17
1-2* Connects 3.3V to DVDDS1
Open Allows external powering of DVDDS1
JU18
1-2* Connects MIC1P to the headphone jack (J2)
Open Disconnects MIC1P from the headphone jack (J2)
JU19 — See Table 3
JU20
2-3*, 5-6* Connects the on-board I
2
C master to the IC
Open Allows external control of the IC over I
2
C
JU22
1-2* Connects 3.3V to DVDDS2
Open Allows external powering of DVDDS2
JU27
1-2 Connects the digital microphone data output to the IC
Open* Disconnects the digital microphone data output from the IC
JU28
1-2*
Connects the MAX98089 interrupt output (IRQ) to the on-board microcontroller
Open
Disconnects the MAX98089 interrupt output (IRQ) to the on-board microcontroller