LMH0356_08 Datasheet, PDF (11/16 Pages) National Semiconductor (TI) – 3 Gbps HD/SD SDI Reclocker with 4:1 Input Mux and FR4 EQs

SD/HD
The SD/HD output indicates whether the LMH0356 is pro-
cessing SD or HD / 3 Gbps data rates. It may be used to
control another device such as the LMH0302 cable driver.
When this output is high it indicates that the data rate is 270
Mbps. When low, the indicated data rate is 1483, 1485, 2967,
or 2970 Mbps. The SD/HD output is a registered function and
is only valid when the PLL is locked and the Lock Detect out-
put is high. When the PLL is not locked (the Lock Detect
output is low), the SD/HD output defaults to HD (low). The SD/
HD output is undefined for a short time after lock detect as-
sertion or de-assertion due to a data rate change on SDI. See
Figure 3 for a timing diagram showing the relationship be-
tween SDI, Lock Detect, and SD/HD.
FIGURE 3. SDI, Lock Detect, and SD/HD Timing
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