Datasheet

SDI Input and SDO Output
The SDI input connector (J1) is a 75Ω BNC connector. The SDI input should conform to the SMPTE 424M,
SMPTE 292M, or SMPTE 259M standards.
The SDO output connectors (J2 and J3) are 50Ω SMA connectors. When using only one side of the output pair,
the other side should be terminated with a 50Ω SMA termination. For example, when only using the SDO output,
SDO
¯¯¯¯
should be terminated with a 50Ω SMA termination.
DC Power Connectors
The VCC and GND power connectors should be powered with a DC input voltage of 3.3V ± 5% (3.6V maximum).
SPI Mode / Pin Mode Select (JP1 – JP4)
JP1, JP2, JP3, and JP4 are used to select between SPI Mode or Pin mode. To select Pin Mode, set four jumpers
as shown in Figure 2, and to select SPI Mode, set four jumpers as shown in Figure 3. Either Pin Mode or SPI
mode must be selected for proper operation; do not leave JP1-JP4 open.
Figure 2. Pin Mode Select Figure 3. SPI Mode Select
MUTE
REF
(JP5)
JP5 allows control of the MUTE
REF
function and may be used in either Pin Mode or SPI Mode. MUTE
REF
is an input
voltage used to set the threshold for CD
¯¯¯
. The MUTE
REF
DC input voltage should be between 0V and 3.3V. Refer
to the LMH0384 datasheet for details. Leave JP5 unconnected for normal operation.
Pin Mode Controls (JP6 – JP8)
JP6, JP7, and JP8 are used to control LMH0384 features while the device is configured for Pin Mode. Jumpers
should not be placed on JP6, JP7, or JP8 while the device is configured for SPI Mode.
CD
¯¯¯
and MUTE (JP6)
JP6 allows Carrier Detect (CD
¯¯¯
) monitoring and MUTE control. CD
¯¯¯
is high when no input signal is present. MUTE
may be used to force the outputs on or off, or tied to CD
¯¯¯
to allow automatic mute operation based on the input
signal. To activate mute and force the outputs into a muted condition, set the jumper to pull MUTE to VCC. To turn
off mute so that the outputs will never mute, set the jumper to tie MUTE to GND. For normal operation, set the
jumper to tie CD
¯¯¯
to MUTE for automatic mute control. The LMH0384 MUTE pin has an internal pulldown (to
disable mute), so JP6 may be left unconnected and the LMH0384 will never mute.
SD384 EVK User Guide 2 of 5
Rev 1.2 © 2009, National Semiconductor Corp.