Datasheet

MAX9260 Evaluation Kit
Evaluates: MAX9260
6 ______________________________________________________________________________________
EV kit. Note that the MAX7324 actually has two device
addresses; for simplicity, the software GUI only displays
the device address associated with MAX7324 outputs.
For details, refer to the MAX7324 IC data sheet.
The PRBS Test tab sheet (Figure 5) uses the MAX9260
registers to perform a pseudorandom bit sequence
(PRBS) error-rate test. Select the test duration (maxi-
mum 32767s = 9.1hrs) and press the Start button. The
software GUI configures the MAX9260 to begin the
PRBS test, counts down the specified delay time, and
then reports the final value of the MAX9260 PRBSERR
register.
The Interface History and Low Level Access tab
sheet (Figure 6) shows the recent low-level commu-
nications activity between the software GUI and the
MAX9259/MAX9260. The Register Access group box
provides arbitrary device read/write control, support-
ing additional user-supplied devices besides the on-
board MAX9259, MAX9260, and MAX7324. The Device
Address, Register, and Data drop-down lists specify
the device address and the register within the device, as
well as one optional byte of data to be written. Pressing
the Write Register button writes one byte of data to
the specified device register. Read Register reads the
specified device register and reports the results into the
Interface History window. Devices that are not register-
based (such as the MAX7324) are supported by Send
Data (no register) and Receive Data (no register).
User-supplied devices requiring other interface proto-
cols must use Raw TX byte codes to communicate.
Note that in bypass mode, raw data is passed to the
user-supplied slave device directly without modification.
Detailed Description of Hardware
The MAX9260 EV kit provides a proven layout for the
MAX9260. On-board level translators, I
2
S stereo audio
DAC, Class D audio power amplifier, and easy-to-use
USB-PC connection are included on the EV kit.
The MAX9260 EV kit board layout is divided into four
principal sections.
From header H1 to connector J1 are the support compo-
nents specific to the MAX9260. On-board LDO regulator
U2 powers the AVDD, DVDD, and IOVDD supplies from
VIN. Jumper JU11 optionally connects VIN to the link
cable, powering the remote EV kit board.
Below header H1, the board layout has three sections:
microcontroller (U10–U14), I
2
C slave device (U15), and
audio (U20–U25). The microcontroller and I
2
C slave
device sections are identical on MAX9259 and MAX9260
EV kits.
The audio section of the MAX9259 EV kit contains
S/PDIF-to-I
2
S audio converter circuits (U20–U25), which
can be disabled by JU210 for applications already hav-
ing I
2
S audio.
The audio section of the MAX9260 EV kit contains I
2
S-
to-audio DAC circuits (U20, U21) and a Class D stereo
power amplifier (U25). The audio DAC circuits are similar
to the MAX9850 EV kit, and the power amplifier circuit is
similar to the MAX9701 EV kit.
User-Supplied Interface
To use the MAX9260 EV kit with a user-supplied inter-
face, first cut the PCB traces at jumpers JU141 and
JU142. Next, apply your own TX/SCL signal at the U1
side of JU141 and RX/SDA at the U1 side of JU142.
Refer to the MAX9259/MAX9260 IC data sheet for details
about UART protocol for base mode, write data format,
read data format, selecting base mode or bypass mode,
and selecting UART or I
2
C slave device.
User-Supplied Power Supply
The MAX9250 and MAX9260 EV kits are powered com-
pletely from the USB port by default. The 5V USB bus
power is supplied to the remote EV kit over the link cable
by default. Jumper JU10 powers the link cable (VBUS)
from the 5V USB supply, and jumper JU11 connects the
link cable VBUS to the VIN power supply.
To provide external power to each EV kit’s VIN, and still
power both microcontrollers from USB, remove the shunt
from JU11, but leave the shunt at JU10 installed. The link
cable will carry the USB 5V bus power to the remote EV
kit board, but external user-supplied VIN supplies are
required to power the MAX9259 and the MAX9260.
To provide different power supplies to DVDD, AVDD, and
IOVDD, remove the shunts from jumpers JU21, JU22,
and JU23, and apply external user-supplied power at the
DVDD, AVDD, and IOVDD oval pads.
The I
2
S audio link demonstration requires both MAX9259
EV kit and MAX9260 EV kit microcontrollers (U12) to be
powered, otherwise the on-board S/PDIF-to-I
2
S con-
verter or the I
2
S audio DAC does not initialize.