
REV. A
AD7725
–5–
Parameter
Symbol
Min
Typ
Max
Unit
CLKIN Frequency
f
CLKIN
114.4
MHz
CLKIN Period (t
CLK = 1/fCLKIN)t1
0.07
1
s
CLKIN Low Pulse Width
t
2
0.45
t
1
0.55
t
1
CLKIN High Pulse Width
t
3
0.45
t
1
0.55
t
1
CLKIN Rise Time
t
4
5ns
CLKIN Fall Time
t
5
5ns
CLKIN to SCO Delay
t
6
35
50
ns
SCO Period:
SCR = 0
t
7
1t
CLK
SCR = 1
t
7
2t
CLK
SERIAL INTERFACE (DSP MODE ONLY)
FSI Setup Time before SCO Transition
t
8
30
ns
FSI Hold Time after SCO Transition
t
9
0ns
SDI Setup Time
t
10
30
ns
SDI Hold Time
t
11
0ns
SERIAL INTERFACE (DSP AND BFR MODES)
SCO Transition to FSO High Delay
t
12
20
ns
SCO Transition to FSO Low Delay
t
13
20
ns
SDO Setup before SCO Transition
t
14
10
ns
SDO Hold after SCO Transition
t
15
0ns
SERIAL INTERFACE (EPROM MODE)
SCO High Time
t
16
8t
CLK
SCO Low Time
t
17
8t
CLK
SOE Low to First SCO Rising Edge
t
18
20
t
CLK
Data Setup before SCO Rising Edge
t
19
22
ns
PARALLEL INTERFACE
DATA WRITE
RS Low to
CS Low
t
20
15
ns
WR Setup before CS Low
t
21
15
ns
RS Hold after
CS Rising Edge
t
22
0ns
CS Pulse Width
t
23
50
ns
WR Hold after CS Rising Edge
t
24
0ns
Data Setup Time
t
25
10
ns
Data Hold Time
t
26
5ns
DATA READ
RS Low to
CS Low
t
27
15
ns
RD Setup before
CS Low
t
28
15
ns
RS Hold after
CS Rising Edge
t
29
0ns
RD Hold after
CS Rising Edge
t
30
0ns
Data Valid after
CS Falling Edge3
t
31
30
ns
Data Hold after
CS Rising Edge
t
32
10
ns
STATUS READ/INSTRUCTION WRITE
CS Duty Cycle
t
33
1t
CLK
Interrupt Clear after
CS Low
t
34
15
ns
RD Setup to
CS Low
t
35
15
ns
RD Hold after
CS Rising Edge
t
36
0ns
Read Data Access Time
3
t
37
30
ns
Read Data Hold after
CS Rising Edge
t
38
10
ns
Write Data Setup before
CS Rising Edge
t
39
10
ns
Write Data Hold after
CS Rising Edge
t
40
5ns
NOTES
1Guaranteed by design.
2Guaranteed by characterization. All input signals are specified with tr
tf
5 ns (10% to 90% of DV
DD) and timed from a voltage level of 1.6 V.
3Measured with the load circuit in Figure 2 and defined as the time required for the output to cross 0.8 V and 2.4 V.
TIMING SPECIFICATIONS1, 2
(AVDD = 5 V
5%; DV
DD = 5 V
5%; AGND = DGND = 0 V, REF2 = 2.5 V,
unless otherwise noted.)