Maxim Integrated
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11
www.maximintegrated.com
Evaluate: MAX9276A/MAX9280A
MAX9276A/MAX9280A
Evaluation Kits
Detailed Description of Hardware
The MAX9276A/MAX9280A deserializer coax EV kit
provides a proven layout for the GMSL deserializers with
the use of a standard FAKRA coax cable. On-board level
translators and an easy-to-use USB-PC connection are
included on the EV kit.
The deserializer EV kit board layout is divided into three
principal sections:
1) Power-supply circuitry (on-board LDO regulators
U2 and U3 power the AVDD, DVDD, and IOVDD
supplies from +5VIN)
2) MAX9276A or MAX9280A and support components.
3) Microcontrollers (U10, U12) and support components
On-Board-Supplied Interface
The EV kit board provides a UART and I
2
C inter-
face (through U10 and U12) that is intended to oper-
ate while both SerDes boards are powered on and
locked. To use the on-board-supplied I
2
C interface,
either use an IOVDD of 2.2V or greater with the I
2
C
interface, or use a 100kbps I
2
C data rate.
User-Supplied Interface
To use the deserializer EV kit with a user-supplied inter-
face, remove shunts from the JU_TXSCL header and
apply a TX/SCL signal to the middle pin of the JU_TXSCL
header. Also remove shunts from the JU_RXSDA header
and apply an RX/SDA signal to the middle pin of the
JU_RX_SDA header.
Refer to the respective SerDes IC data sheets for details
about UART protocol for base mode, write data format,
read data format, selecting base mode or bypass mode,
and selecting a UART or I
2
C slave device.
User-Supplied Power Supply
The deserializer EV kit can be powered completely from
the USB port by default. Jumper JU_VIN selects between
the 5V USB supply or the +5VIN user-supplied power
supply to power up U1 and supporting circuitry.
To provide different power supplies to AVDD, DVDD, and
IOVDD, move the shunts on the JU_AVDD, JU_DVDD,
and JU_IOVDD headers from the INT to the EXT
positions and apply external user-supplied power at the
AVDD_EXT, DVDD_EXT, and IOVDD_EXT terminals,
respectively.
Detailed Description of Firmware
The DS89C450 microcontroller (U12) runs custom
firmware that ensures no breaks occur within register
read/write commands. The firmware records 9-bit even-
parity data received from the USB interface while RTS is
set, and plays back the 9-bit data with 1.5 stop bits timing
when RTS is cleared. Data received by the deserializer is
immediately relayed to the USB port.
The serializer coax EV kit provides a proven layout for
the MAX9275/MAX9279 GMSL serializer with the use of
a standard FAKRA coax cable. On-board level translators
and an easy-to-use USB-PC connection are included on
the EV kit.