max9247etmt Maxim Integrated Products, Inc., max9247etmt Datasheet - Page 11
max9247etmt
Manufacturer Part Number
max9247etmt
Description
Max9247 27-bit, 2.5mhz-to-42mhz Dc-balanced Lvds Serializer
Manufacturer
Maxim Integrated Products, Inc.
Datasheet
1.MAX9247ETMT.pdf
(19 pages)
The transition words require interconnect bandwidth
and displace control data. Therefore, control data is not
sampled (see Figure 9):
• Two clock cycles before DE_IN goes high
• During the video phase
• Two clock cycles after DE_IN goes low
The last sampled control data are latched at the deserial-
izer control data outputs during the transition and video
phases. Video data are latched at the deserializer RGB
data outputs during the transition and control phases.
AC-coupling increases the common-mode voltage to
the voltage rating of the capacitor. Two capacitors are
sufficient for isolation, but four capacitors—two at the
serializer output and two at the deserializer input—pro-
vide protection if either end of the cable is shorted to a
high voltage. AC-coupling blocks low-frequency
ground shifts and common-mode noise. The MAX9247
serializer can also be DC-coupled to the MAX9248/
MAX9250 deserializers.
Figures 10 and 12 show an AC-coupled serializer and
deserializer with two capacitors per link. Figures 11 and
Figure 9. Transition Timing
CNTL_IN
PCLK_IN
RGB_IN
DE_IN
CONTROL
Applications Information
PHASE
= NOT SAMPLED BY PCLK_IN
______________________________________________________________________________________
AC-Coupling Benefits
TRANSITION
Transition Timing
PHASE
DC-Balanced LVDS Serializer
27-Bit, 2.5MHz-to-42MHz
VIDEO PHASE
13 show the AC-coupled serializer and deserializer with
four capacitors per link.
See Figure 14 for calculating the capacitor values for
AC-coupling depending on the parallel clock frequen-
cy. The plot shows capacitor values for two- and four-
capacitor-per-link systems. For applications using less
than 18MHz clock frequency, use 0.1µF capacitors.
The RNG[1:0] inputs select the operating frequency
range of the MAX9247 serializer. An external clock with-
in this range is required for operation. Table 3 shows
the selectable frequency ranges and corresponding
data rates for the MAX9247.
Table 3. Parallel Clock Frequency Range
Select
RNG1
0
0
1
1
Selection of AC-Coupling Capacitors
RNG0
Frequency-Range Setting RNG[1:0]
0
1
0
1
CLOCK (MHz)
PARALLEL
10 to 20
20 to 42
2.5 to 5
TRANSITION
5 to10
PHASE
SERIAL-DATA RATE
CONTROL
PHASE
100 to 200
200 to 400
400 to 840
50 to 100
(Mbps)
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