
AD7854/AD7854L
TIMNGSPECIFICATIONS
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
MN
to T
MAX
, unless otherwse noted)
–4–
REV. 0
Limit at T
MIN
, T
MAX
(A, B, S Versions)
Parameter
5 V
3 V
Units
Description
f
CLK IN2
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
CLK IN
50
50
40
40
2.5 t
CLK IN
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
CLK IN
70
70
60
60
2.5 t
CLK IN
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
Pulse Width
CONVST
to BUSY
↑
Propagation Delay
Conversion T ime = 18 t
CLK IN
L Version 1.8 MHz CLK IN. Conversion T ime = 18 t
CLK IN
HBEN to RD
Setup T ime
HBEN to RD
Hold T ime
CS
to
RD
to Setup T ime
CS
to
RD
Hold T ime
RD
Pulse Width
Data Access T ime After
RD
Bus Relinquish T ime 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
17
t
184
t
19
t
20
t
21
t
22
t
23
t
CAL6
Minimum T ime Between Reads
HBEN to
WR
Setup T ime
HBEN to
WR
Hold T ime
CS
to
WR
Setup T ime
CS
to
WR
Hold T ime
WR
Pulse Width
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 T ime, Master Clock Dependent (125013
t
CLK IN
)
Internal DAC Plus System Full-Scale Cal T ime, Master Clock
Dependent (111124 t
CLK IN
)
System Offset Calibration T ime, Master Clock Dependent
(13889 t
CLK IN
)
t
CAL16
27.78
27.78
ms typ
t
CAL26
3.47
3.47
ms typ
NOT ES
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
T he
CONVST
pulse width here only applies for normal operation. When the part is in power-down mode, a different
CONVST
pulse width 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. T he measured number is then extrapolated
back to remove the effects of charging or discharging the 50 pF capacitor. T his 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
T he 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.