SDI Input and SDO Output
The SDI input connectors (J1 and J2) are 50
Ω
SMA connectors. The SD303/SD307 is initially configured for 100
Ω
differential input. To configure the SD303/SD307 for 50
Ω
single-ended input, remove R28 and place 49.9
Ω
0402
resistors in R9 and R10. When using only one input, the other input should be terminated with a 50
Ω
SMA
termination.
The SDO output connectors (J3 and J4 for the SD303; and J3, J4, J5, and J6 for the dual output SD307) are 75
Ω
BNC connectors. When using only one side of an output pair, the other side should be terminated with a 75
Ω
BNC
termination. For example, when only using SDO0 on the LMH0307, SDO0
¯¯¯¯¯ should be terminated with a 75
Ω
BNC
termination.
DC Power Connectors and USB Connector
The red and black binding posts (J8 and J9) provide power for the LMH0303/LMH0307 device, and the USB
connection provides power for the remaining board functions, including the microcontroller and the LEDs.
For
proper operation, the SD303/SD307 should first be powered with a DC input voltage (between J8 and J9) of
3.3V ± 5% (3.6V maximum), and then the USB cable should be connected between the evaluation board and
the PC.
The POWER LED will flash Red while the board is powered from the 3.3 VDC supply alone, and then
change to solid Green once the USB cable is connected to the PC. The POWER LED will remain Green as long as
the board is powered correctly.
JP1 – LMH0303/LMH0307 Jumper Connection to Microcontroller
A jumper block should be placed on JP1 to connect the LMH0303/LMH0307 pins to the microcontroller. The ALP
software will not function correctly if this jumper block is not in place. Separate jumpers may be used, but they
must be placed to connect the following pins of JP1: RSTI
¯¯¯¯ (pins 5-6), ENABLE (pins 7-8), SDA (pins 9-10), SCL
(pins 11-12), SD/HD (pins 13-14), FAULT
¯¯¯¯¯¯ (pins 15-16), and RSTO
¯¯¯¯¯ (pins 17-18). This jumper block (or individual
jumpers) may be removed to control the LMH0303/LMH0307 pins externally, but then the microcontroller will no
longer be able to communicate with the cable driver.
Controls and Indicators
ENABLE
The ENABLE push button switch controls ENABLE, and the ENABLE LED shows its state. The ENABLE LED is
Green when the cable driver is enabled (ENABLE = 1), and Red when the cable driver is disabled (ENABLE = 0).
When the cable driver is disabled, it enters a deep power down mode, and Termination Fault detection and LOS
¯¯¯¯
detection no longer function.
If the LOSEN register bit (bit 4 of register 05h) is set, then the cable driver can be disabled with LOS
¯¯¯¯ detection still
functioning. With LOSEN set, LOS
¯¯¯¯ is combined with the ENABLE functionality. In this mode, disabling the device
by pushing the ENABLE switch will still power down the device completely (including powering down Termination
Fault detection and LOS
¯¯¯¯ detection), but if ENABLE is left active and the signal is removed from the input, the
device will power down with the LOS
¯¯¯¯ detection still functioning. When the input signal is reapplied, the device will
power back on.
SD/HD
The SD/HD push button switch controls SD/HD, and the SD/HD LED shows its state. The SD/HD LED is Green
when the cable driver is configured for HD/3G edge rates (SD/HD = 0), and Red when the cable driver is configured
for SD edge rates (SD/HD = 1). The default setting for the SD/HD LED is Green for HD/3G edge rates.
SD303/SD307 EVK User Guide
3 of 27
Rev 1.2
© 2010, National Semiconductor Corp.
