Datasheet

MAX3816A
I
2
C 2-Wire Extender for DDC in DVI,
HDMI, and VGA Interfaces
14 ______________________________________________________________________________________
MAX3816A External to Display, Switchable Series
and Parallel Mode Advantages (See Figure 7)
• Long cable reach.
• In parallel mode, the MAX3816A is very tolerant of
noncompliant DDC sources and sinks.
• The MAX3816A can be turned off and bypassed if
another MAX3816A or speed-up device is being
used on the same DDC.
• In parallel mode, the MAX3816A can be used simul-
taneously with other I
2
C speed-up devices.
• The MAX3816A acts as a buffer between source and
display. Hence, source reflections are isolated to the
source side of the MAX3816A, protecting display
circuits from possible double clocking due to stair-
step waveforms caused by very long cables with
reflections.
• In series mode, the MAX3816A can be turned off
(DRVR_EN asserted low) to isolate between source
and display buses. The display bus can then oper-
ate independently of source-cable loading or mal-
functions.
Consideration
Use a good quality CMOS switch with low resistance
(< 20Ω) and over/undervoltage tolerance.
Figure 7. External to Display, Switchable Series and Parallel Mode
MAX3816A
MAX4719
DRVR_EN
CLK_C
DATA_C
MODE
CLK_D
DATA_D
ENA
LONG CABLE
FROM SOURCE
+5V
BYP
SER
PAR
+5V
+5V
47kΩ47kΩ
3.3kΩ
CONNECTOR
TO DISPLAY
10
+5V
3.3kΩ
10
SERIES MODE: DRVR_EN = HI (ENA), MODE = LO (SER)
PARALLEL MODE: DRVR_EN = HI (ENA), MODE = HI (PAR)
BYPASS MODE: DRVR_EN = LO (BYP), MODE = HI (PAR)
ISOLATE MODE: DRVR_EN = LO (BYP), MODE = LO (SER)