SD/HD
The SD/HD checkbox controls the state of the SD/HD pin. This checkbox is un-checked by default to enable
HD/3G mode. Enabling this checkbox sets the cable driver edge rates to SD mode.
SDO Amp
The SDO Amp controls set the amplitude of the output driver(s). The LMH0307 has two independently configurable
outputs (SDO0 and SD01) and the LMH0303 has a single configurable output (SDO). For the LMH0307,
SDO Amp 0 configures the AMP0 bits in the OUTPUT0 register (04h), and SDO Amp 1 configures the AMP1 bits in
the OUTPUT1 register (06h). For the LMH0303, SDO Amp configures the AMP bits in the OUTPUT register (04h).
The default amplitude setting is 0x10 for 800 mV
P-P
. The output amplitude may be lowered to around 720 mV
P-P
and increased to around 880 mV
P-P
in roughly 5 mV increments.
LED Icons
The diagram of the LMH0303/LMH0307 device is framed by a number of colored LED icons that represent the LED
state on the board. Note that either the Refresh button or the Auto Refresh checkbox must be used to update the
LED icons in the LMH0303/LMH0307 tab to reflect any board changes.
FAULT LED
The FAULT LED shows the current state of the FAULT
¯¯¯¯¯¯ pin. The FAULT LED is Green to indicate no faults are
detected (FAULT
¯¯¯¯¯¯ = 1) and Red to indicate one or more faults have been detected (FAULT
¯¯¯¯¯¯ = 0). The Auto Refresh
checkbox should be checked in order to actively monitor the state of the FAULT
¯¯¯¯¯¯ pin.
FAULT
¯¯¯¯¯¯ is triggered and set low for a Termination Fault on any output or the loss of signal on the input. FAULT
¯¯¯¯¯¯ is
cleared and set high again when the faults have been removed by either terminating the outputs, applying the input
signal, or changing the register settings in the MASK or DIRECTION registers.
Registers Tab
The Registers tab displays all registers for the LMH0303 or LMH0307. Figure 6 shows the Registers tab for the
LMH0307. The Value field indicates the value of the currently selected register.
SD303/SD307 EVK User Guide
11 of 27
Rev 1.2
© 2010, National Semiconductor Corp.
