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AC Electrical Characteristics
(Continued)
The following specifications apply for V
CC
=5V, t
r
=t
f
=20 ns, V
REF
(+)=5V, V
REF
(−)=0V and T
A
=25˚C unless otherwise speci-
fied.
Typ
Tested
Design
Parameter
Conditions
(Note 6)
Limit
Limit
Units
(Note 7)
(Note 8)
t
ACC2
, Access Time (Delay from
Falling Edge of RD to Output
Valid)
Pin 7 = V
CC
, t
RD
>
t
I
;
Figure 4
C
L
=15 pF
70
120
ns
C
L
=100 pF
90
150
ns
t
ACC3
, Access Time (Delay from
Rising Edge of RDY to Output
Valid)
R
PULLUP
= 1k and C
L
= 15 pF
30
ns
t
I
, Internal Comparison Time
Pin 7=V
CC
;
Figures 4, 5
800
1300
ns
C
L
=50 pF
t
1H
, t
0H
, TRI-STATE Control
R
L
=1k, C
L
=10 pF
100
200
ns
(Delay from Rising Edge of RD to
Hi-Z State)
t
INTL
, Delay from Rising Edge of
Pin 7 = V
CC
, C
L
= 50 pF
WR to Falling Edge of INT
t
RD
>
t
I
;
Figure 4
t
I
ns
t
RD
<
t
I
;
Figure 3
t
RD
+200
t
RD
+290
ns
t
INTH
, Delay from Rising Edge of
Figures 2, 3, 4
125
225
ns
RD to Rising Edge of INT
C
L
=50 pFc
t
INTHWR
, Delay from Rising Edge of
Figure 5, C
L
=50 pF
175
270
ns
WR to Rising Edge of INT
t
RDY
, Delay from CS to RDY
Figure 2, C
L
=50 pF, Pin 7 =0
50
100
ns
t
ID
, Delay from INT to Output Valid
Figure 5
20
50
ns
t
RI
, Delay from RD to INT
Pin 7=V
CC
, t
RD
<
t
I
200
290
ns
Figure 3
t
P
, Delay from End of Conversion
Figures 2, 3, 4, 5
500
ns
to Next Conversion
(Note 4) See Graph
Slew Rate, Tracking
0.1
V/µs
C
VIN
, Analog Input Capacitance
45
pF
C
OUT
, Logic Output Capacitance
5
pF
C
IN
, Logic Input Capacitance
5
pF
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating
the device beyond its specified operating conditions.
Note 2: All voltages are measured with respect to the GND pin, unless otherwise specified.
Note 3: Total unadjusted error includes offset, full-scale, and linearity errors.
Note 4: Accuracy may degrade if t
WR
or t
RD
is shorter than the minimum value specified. See Accuracy vs t
WR
and Accuracy vs t
RD
graphs.
Note 5: When the input voltage (V
IN
) at any pin exceeds the power supply rails (V
IN
<
V
−
or V
IN
>
V
+
) the absolute value of current at that pin should be limited to
1 mA or less. The 4 mA package input current limits the number of pins that can exceed the power supply boundaries with a 1 mA current limit to four.
Note 6: Typicals are at 25˚C and represent most likely parametric norm.
Note 7: Tested limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 8: Design limits are guaranteed but not 100% tested. These limits are not used to calculate outgoing quality levels.
Note 9: Human body model, 100 pF discharaged through a 1.5 k
Ω
resistor.
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