AD7886
–3–
REV. B
TIMING CHARACTERISTICS
1
(V
DD
= +5 V 6 5%, V
SS
= –5 V 6 5%, AGND = DGND = 0 V)
Limit at Limit at Limit at
T
MIN
, T
MAX
T
MIN
, T
MAX
T
MIN
, T
MAX
Parameter (J, K Versions) (B Version) (T Version) Units Conditions/Comments
t
1
50 50 50 ns min CONVST Pulse Width
1 1 1 Fs max
t
2
0 0 0 ns min CS to RD Setup Time
t
3
0 0 0 ns min CS to RD Hold Time
t
4
60 60 75 ns min RD Pulse Width
t
5
100 100 100 ns max CONVST to BUSY Propagation Delay, (C
L
= 10 pF)
t
6
57 57 70 ns max Data Access Time After RD
t
7
3
10 10 10 ns min Bus Relinquish Time After RD
50 50 60 ns max
t
8
20 20 14 ns min Data Setup Time Prior to BUSY, (C
L
= 20 pF)
10 10 0 ns min Data Setup Time Prior to
BUSY, (C
L
= 100 pF)
t
9
3
10 10 10 ns min Bus Relinquish Time After CONVST
100 100 100 ns max
t
10
0 0 0 ns min CS High to CONVST Low
t
11
0 0 0 ns min BUSY High to RD Low
t
12
250 250 250 ns typ BUSY High to CONVST Low, SHA Acquisition Time
t
13
1.333 1.333 1.333 µs min Sampling Interval
t
CONV
950 950 950 ns typ Conversion Time
1000 1000 1000 ns max
NOTES
1
Timing specifications in bold print are 100% production tested. All other times are sample tested at +25°C to ensure compliance. All input signals are specified with tr =
tf = 5 ns (10% to 90% of 5 V) and timed from a voltage level of 1.6 V.
2
t
6
is measured with the load circuit of Figure 1 and defined as the time required for an output to cross 0.8 V or 2.4 V.
3
t
7
and t9 are derived from the measured time taken by the data outputs to change by 0.5 V when loaded with the circuit of Figure 1. The measured number is then extrapo-
lated back to remove the effects of charging or discharging the load capacitor, C
L
. This means that the times, t
7
and t
9
, quoted in the timing characteristics are the true bus
relinquish times of the part and as such are independent of external bus loading capacitances.
Specifications subject to change without notice.
WARNING!
ESD SENSITIVE DEVICE
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD7886 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
TO OUTPUT
PIN
+2.1V
I
OH
I
OL
C
L
Figure 1. Load Circuit for Bus Access and Relinquish Time
ABSOLUTE MAXIMUM RATINGS
1, 2
(T
A
= +25°C unless otherwise noted)
V
DD
to AGND . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V
V
SS
to AGND . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –7 V
AGND to DGND . . . . . . . . . . . . . . . . . –0.3 V to V
DD
+0.3 V
VIN1, VIN2, SUM, +5REF to AGND . . . . . . –15 V to +15 V
V
REF
to AGND . . . . . . . . . . . . . . . . V
SS
–0.3 V to V
DD
+0.3 V
Digital Inputs to DGND
CS, RD, CONVST . . . . . . . . . . . . . . –0.3 V to V
DD
+0.3 V
Digital Outputs to DGND
DB0 to DB11, BUSY . . . . . . . . . . . . . –0.3 V to V
DD
+0.3 V
Operating Temperature Range
Commercial (J, K Versions) . . . . . . . . . . . . . . 0°C to +70°C
Industrial (B Version) . . . . . . . . . . . . . . . . –40°C to +85°C
Extended (T Version) . . . . . . . . . . . . . . . –55°C to +125°C
Storage Temperature Range . . . . . . . . . . . .–65°C to + 150°C
Lead Temperature (Soldering, 10 secs) . . . . . . . . . . . .+300°C
Power Dissipation (Any Package) to +75°C . . . . . . 1000 mW
Derates above +75°C by . . . . . . . . . . . . . . . . . . . . 10 mW/°C
NOTES
1
Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. This is a stress rating only; functional operation
of the device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
2
If V
SS
is open circuited with V
DD
and AGND applied, the V
SS
pin will be pulled
positive, exceeding the Absolute Maximum Ratings. If this possibility exists, a
Schottky diode from V
SS
to DGND (cathode end to GND) ensures that the
