National Semiconductor DS36C278 s and, Specifications And Installation Manual

Page: 4 / 10

Switching Characteristics
(Continued)
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified (Notes 3 and 8)
Symbol Parameter Conditions Reference Min Typ Max Units
RECEIVER CHARACTERISTICS
t
PHL
Propagation Delay C
L
e
15 pF
Figures 12, 13
30 210 400 ns
High to Low
t
PLH
Propagation Delay
30 190 400 ns
Low to High
t
SK
Skew,
l
t
PHL
b
t
PLH
l
0 20 50 ns
t
PLZ
Output Disable Time C
L
e
15 pF
Figures 14, 15, 16
Ð 50 150 ns
t
PHZ
Ð 55 150 ns
t
PZL
Output Enable Time Ð 40 150 ns
t
PZH
Ð 45 150 ns
Note 1: ‘‘Absolute Maximum Ratings’’ are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The table of ‘‘Electrical Characteristics’’ specifies conditions of device operation.
Note 2: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except V
OD1
and
V
OD2
.
Note 3: All typicals are given for: V
CC
e a
5.0V, T
A
e a
25 § C.
Note 4: Delta
l
V
OD2
l
and Delta
l
V
OC
l
are changes in magnitude of V
OD2
and V
OC
, respectively, that occur when input changes state.
Note 5: Threshold parameter limits specified as an algebraic value rather than by magnitude.
Note 6: Hysteresis defined as V
HST
e
V
TH
b
V
TL
.
Note 7: I
IN
includes the receiver input current and driver TRI-STATE leakage current.
Note 8: C
L
includes probe and jig capacitance.
Note 9: For complete details of test, see RS-485.
Parameter Measurement Information
TL/F/12040 – 2
FIGURE 1. Driver V
OD2
and V
OC
TL/F/12040 – 18
FIGURE 2. Driver V
OD3
TL/F/12040 – 3
FIGURE 3. Driver V
OH
and V
OL
TL/F/12040 – 4
Vtest
e b
7V to
a
12V
FIGURE 4. Driver I
OSD
TL/F/12040 – 5
FIGURE 5. Driver Differential Propagation Delay Test Circuit
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