BU16025MUV_11 Datasheet, PDF (14/17 Pages) Rohm – 1 for input 1 output buffer (Sync with OE)

BU16025MUV
Technical Note
3) Serial connection of TMDS differential line
The serial connections of TMDS differential line like fig15 decrease the jitter tolerant characteristic. Especially when
system needs 1080p (12bit) data rate, deterioration of Jitter tolerance is outstanding. This problem also depends on
receiver IC characteristic. When 1080p (12bit) is required , Rohm doesn’t recommend cascade connect application.
Vcc
RINT
RINT
Vcc
RINT
RINT
A
TMDS
TMDS
Y
Receiver
Driver
B
Z
A
TMDS
TMDS
Y
Receiver
Driver
B
Z
Fig 15 cascade connection notice
4) DDC line connections
DDC buffer of SDAｘ/SCLx and SDAy/SCLy have different low threshold level. Connect like below
RT
AVCC
RT
Recommend application of BU16025MUV
Source Equipment
MASTER
BU16025MUV
SDAx
SCLx
SDAy
SCLy
Repeater Equipment
BU16025MUV
SDAy
SCLy
SDAx
SCLx
Sink Equipment
BU16025MUV
SDAy
SCLy
SDAx
SCLx
SLAVE
Recommend application of BU16025MUV and BU160xxKV(*)
Source Equipment
MASTER
BU16025MUV
SDAx
SCLx
SDAy
SCLy
Repeater Equipment
BU16025MUV
SDAy
SCLy
SDAx
SCLx
Sink Equipment
BU160xxKV(*)
SDA
SCL
SDA_SINK
SCL_SINK
SLAVE
(*)BU160xxKV → BU16006/16018/16027/16024KV
Fig 16 DDC connection notice
5) AC Coupling
This IC can also communicate using AC coupling capacitor with TMDS line. But even connecting AC coupling capacitor,
AC current may flow if input common mode voltage between two devices is different. This AC current may damage the
lower common mode voltage devices like PCIe or DisplayPort.
6) TMDS output offset voltage
Offset voltage may appear to TMDS output when there is no signal to TMDS input differential line. OE should be set to
“H” to avoid it.
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2011.01 - Rev.A