DS90LV018A Datasheet, PDF (3/10 Pages) National Semiconductor (TI) – 3V LVDS Single CMOS Differential Line Receiver

Switching Characteristics (Continued)
Note 10: t_SKD4, part to part skew, is the differential channel-to-channel skew of any event between devices. This specification applies to devices over the recom-
mended operating temperature and voltage ranges, and across process distribution. t_SKD4 is defined as |Max − Min| differential propagation delay.
Note 11: V_CC is always higher than R_IN+ and R_IN− voltage. R_IN+ and R_IN− are allowed to have voltage range −0.05V to +3.05V. V_ID is not allowed to be greater than
100 mV when V_CM = 0V or 3V.
Note 12: f_MAX generator input conditions: t_r = t_f < 1 ns (0% to 100%), 50% duty cycle, differential (1.05V to 1.35V peak to peak). Output criteria: 60%/40% duty cycle,
V_OL (max 0.4V), V_OH (min 2.7V), load = 15 pF (stray plus probes).
Parameter Measurement Information
DS100078-3
FIGURE 1. Receiver Propagation Delay and Transition Time Test Circuit
DS100078-4
FIGURE 2. Receiver Propagation Delay and Transition Time Waveforms
Typical Application
Balanced System
FIGURE 3. Point-to-Point Application
DS100078-5
Applications Information
General application guidelines and hints for LVDS drivers
and receivers may be found in the following application
notes: LVDS Owner’s Manual (lit #550062-001), AN808,
AN1035, AN977, AN971, AN916, AN805, AN903.
LVDS drivers and receivers are intended to be primarily used
in an uncomplicated point-to-point configuration as is shown
in Figure 3. This configuration provides a clean signaling en-
vironment for the fast edge rates of the drivers. The receiver
is connected to the driver through a balanced media which
may be a standard twisted pair cable, a parallel pair cable, or
simply PCB traces. Typically the characteristic impedance of
the media is in the range of 100Ω. A termination resistor of
100Ω should be selected to match the media, and is located
as close to the receiver input pins as possible. The termina-
tion resistor converts the driver output (current mode) into a
voltage that is detected by the receiver. Other configurations
are possible such as a multi-receiver configuration, but the
effects of a mid-stream connector(s), cable stub(s), and
other impedance discontinuities as well as ground shifting,
noise margin limits, and total termination loading must be
taken into account.
The DS90LV018A differential line receiver is capable of de-
tecting signals as low as 100 mV, over a ±1V common-mode
range centered around +1.2V. This is related to the driver off-
set voltage which is typically +1.2V. The driven signal is cen-
tered around this voltage and may shift ±1V around this cen-
ter point. The ±1V shifting may be the result of a ground
potential difference between the driver’s ground reference
and the receiver’s ground reference, the common-mode ef-
fects of coupled noise, or a combination of the two. The AC
parameters of both receiver input pins are optimized for a
recommended operating input voltage range of 0V to +2.4V
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