National DS36C278 Home Security System User Manual


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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
02050ns
t
PLZ
Output Disable Time C
L
e
15 pF
Figures 14 15 16
50 150 ns
t
PHZ
55 150 ns
t
PZL
Output Enable Time 40 150 ns
t
PZH
45 150 ns
Note 1‘‘Absolute Maximum Ratings’’ arethose values beyondwhich the safetyof the devicecannot be guaranteedThey are notmeant to implythat 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
ea
50V T
A
ea
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
eb
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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