DS90C402 Datasheet, PDF (4/8 Pages) National Semiconductor (TI) – Dual Low Voltage Differential Signaling (LVDS) Receiver

Applications Information (Continued)
2. Terminated Input. If the driver is disconnected (cable
unplugged), or if the driver is in a power-off condition,
the receiver output will again be in a HIGH state, even
with the end of cable 100Ω termination resistor across
the input pins. The unplugged cable can become a float-
ing antenna which can pick up noise. If the cable picks
up more than 10mV of differential noise, the receiver
may see the noise as a valid signal and switch. To insure
that any noise is seen as common-mode and not differ-
ential, a balanced interconnect should be used. Twisted
pair cable will offer better balance than flat ribbon cable
3. Shorted Inputs. If a fault condition occurs that shorts
the receiver inputs together, thus resulting in a 0V differ-
ential input voltage, the receiver output will remain in a
HIGH state. Shorted input fail-safe is not supported
across the common-mode range of the device (GND to
2.4V). It is only supported with inputs shorted and no ex-
ternal common-mode voltage applied.
Pin Descriptions
Pin
Name
No.
Description
2, 6 R_OUT Receiver output pin
3, 7
R_IN+ Positive receiver input pin
4, 8
R_IN- Negative receiver input pin
5
GND Ground pin
1
V_CC Positive power supply pin,
+5V ± 10%
www.national.com
4