AD7863
Rev. B | Page 5 of 24
TIMING CHARACTERISTICS
VDD = 5 V ± 5%, AGND = DGND = 0 V, REF = Internal. All specifications TMIN to TMAX, unless otherwise noted.
Table 2.
A, B Versions
Unit
Test Conditions/Comments
tCONV
5.2
μs max
Conversion time
tACQ
0.5
μs max
Acquisition time
Parallel Interface
t1
0
ns min
CS to RD setup time
t2
0
ns min
CS to RD hold time
t3
35
ns min
CONVST pulse width
t4
45
ns min
RD pulse width
30
ns min
Data access time after falling edge of RD
5
ns min
Bus relinquish time after rising edge of RD
30
ns max
t7
10
ns min
Time between consecutive reads
t8
400
ns min
Quiet time
1 Sample tested at 25°C to ensure compliance. All input signals are measured with tr = tf = 1 ns (10% to 90% of 5 V) and timed from a voltage level of 1.6 V.
3 Measured with the load circuit of Figure 3 and defined as the time required for an output to cross 0.8 V or 2.0 V. 4 These times are derived from the measured time taken by the data outputs to change 0.5 V when loaded with the circuit of Figure 3. The measured number is then extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. This means that the times quoted in the timing characteristics are the true bus
relinquish times of the part and as such are independent of external bus loading capacitances.
VA1
VA2
VB1
VB2
CONVST
BUSY
A0
CS
RD
DATA
tCONV = 5.2s
06
41
1-
0
02
t3
t8
tACQ
t1
t4
t2
t5
t6
t7
Figure 2. Timing Diagram
TO OUTPUT
PIN
1.6mA
200A
50pF
06
41
1-
0
03
Figure 3. Load Circuit for Access Time and Bus Relinquish Time