
AD7854/AD7854L
TIMING SPECIFICATIONS
1
(AV
DD
= DV
DD
= +3.0 V to +5.5 V; f
CLKIN
= 4 MHz for AD7854 and 1.8 MHz for AD7854L;
T
A
= T
MIN
to T
MAX
, unless otherwise noted)
–4–
REV. B
Limit at T
MIN
, T
MAX
(A, B, S Versions)
Parameter
f
CLKIN2
5 V
3 V
Units
Description
500
4
1.8
100
50
4.5
10
15
5
0
0
55
50
5
40
60
0
5
0
0
55
10
5
1/2 t
CLKIN
50
50
40
40
2.5 t
CLKIN
31.25
500
4
1.8
100
90
4.5
10
15
5
0
0
70
50
5
40
70
0
5
0
0
70
10
5
1/2 t
CLKIN
70
70
60
60
2.5 t
CLKIN
31.25
kHz min
MHz max
MHz max
ns min
ns max
μ
s max
μ
s max
ns min
ns min
ns min
ns min
ns min
ns max
ns min
ns max
ns min
ns min
ns max
ns min
ns max
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ms typ
Master Clock Frequency
L Version
CONVST
Pulsewidth
CONVST
to BUSY
↑
Propagation Delay
Conversion Time = 18 t
CLKIN
L Version 1.8 MHz CLKIN. Conversion Time = 18 t
CLKIN
HBEN to
RD
Setup Time
HBEN to
RD
Hold Time
CS
to
RD
to Setup Time
CS
to
RD
Hold Time
RD
Pulsewidth
Data Access Time After
RD
Bus Relinquish Time After
RD
t
13
t
2
t
CONVERT
t
3
t
4
t
5
t
6
t
7
t
84
t
95
t
10
t
11
t
12
t
13
t
14
t
15
t
16
t
t
17
t
19
t
20
t
21
t
22
t
t
23
Minimum Time Between Reads
HBEN to
WR
Setup Time
HBEN to
WR
Hold Time
CS
to
WR
Setup Time
CS
to
WR
Hold Time
WR
Pulsewidth
Data Setup Time Before
WR
Data Hold Time After
WR
New Data Valid Before Falling Edge of BUSY
HBEN High Pulse Duration
HBEN Low Pulse Duration
Propagation Delay from HBEN Rising Edge to Data Valid
Propagation Delay from HBEN Falling Edge to Data Valid
CS
↑
to BUSY
↑
in Calibration Sequence
Full Self-Calibration Time, Master Clock Dependent (125013
t
CLKIN
)
Internal DAC Plus System Full-Scale Cal Time, Master Clock
Dependent (111124 t
CLKIN
)
System Offset Calibration Time, Master Clock Dependent
(13889 t
CLKIN
)
t
CAL16
27.78
27.78
ms typ
t
CAL26
3.47
3.47
ms typ
NOTES
1
Sample tested at +25
°
C to ensure compliance. All input signals are specified with tr = tf = 5 ns (10% to 90% of V
DD
) and timed from a voltage level of 1.6 V.
2
Mark/Space ratio for the master clock input is 40/60 to 60/40.
3
The
CONVST
pulsewidth here only applies for normal operation. When the part is in power-down mode, a different
CONVST
pulsewidth applies (see Power-Down
section).
4
Measured with the load circuit of Figure 1 and defined as the time required for the output to cross 0.8 V or 2.4 V.
5
t
is derived form the measured time taken by the data outputs to change 0.5 V when loaded with the circuit of Figure 1. The measured number is then extrapolated
back to remove the effects of charging or discharging the 50 pF capacitor. This means that the time, t
9
, quoted in the timing characteristics is the true bus relinquish
time of the part and is independent of the bus loading.
6
The typical time specified for the calibration times is for a master clock of 4 MHz. For the L version the calibration times will be longer than those quoted here due to
the 1.8 MHz master clock.
Specifications subject to change without notice.