
AD7701
REV. D
–6–
1.6mA
200
μ
A
C
L
100pF
TO
OUTPUT
PIN
IOH
2.1V
+
I
OL
Figure 1. Load Circuit for Access
Time and Bus Relinquish Time
DATA
VALID
t
10
HI-Z
SDATA
CS
Figure 3. SSC Mode Data Hold
Time
CAL
SC1, SC2
SC1,SC2 VALID
t
1
t
2
Figure 2a. Calibration Control Timing
DATA
VALID
t
15
HI-Z
SDATA
CS
Figure 4a. SEC Mode Data Hold Time
CLKIN
SLEEP
t
3
Figure 2b.
SLEEP
Mode Timing
HI-Z
DB15
DB14
DB1
DB0
HI-Z
SDATA
DRDY
CS
t
12
t
11
t
13
t
14
SCLK
t
16
Figure 4b. SEC Mode Timing Diagram
T E RMINOLOGY
LINE ARIT Y E RROR
T his is the maximum deviation of any code from a straight line
passing through the endpoints of the transfer function. T he
endpoints of the transfer function are Zero-Scale (not to be
confused with Bipolar Zero), a point 0.5 LSB below the first
code transition (000 . . . 000 to 000 . . . 001) and Full-Scale, a
point 1.5 LSB above the last code transition (111 . . . 110 to
111 . . . 111). T he error is expressed as a percentage of full
scale.
DIFFE RE NT IAL LINE ARIT Y E RROR
T his is the difference between any code’s actual width and the
ideal (1 LSB) width. Differential Linearity Error is expressed in
LSBs. A differential linearity specification of
±
1 LSB or less
guarantees monotonicity.
POSIT IVE FULL-SCALE E RROR
Positive Full-Scale Error is the deviation of the last code
transition (111 . . . 110 to 111 . . . 111) from the ideal (V
REF
–3/2 LSBs). It applies to both positive and negative analog input
ranges and it is expressed in microvolts.
UNIPOLAR OFFSE T E RROR
Unipolar Offset Error is the deviation of the first code transition
from the ideal (AGND + 0.5 LSB) when operating in the uni-
polar mode. It is expressed in microvolts.
BIPOLAR ZE RO E RROR
T his is the deviation of the midscale transition (0111 . . . 111 to
1000 . . . 000) from the ideal (AGND – 0.5 LSB) when
operating in the bipolar mode. It is expressed in microvolts.
BIPOLAR NE GAT IVE FULL-SCALE E RROR
T his is the deviation of the first code transition from the ideal
(–V
REF
+ 0.5 LSB), when operating in the bipolar mode. It is
expressed in microvolts.
POSIT IVE FULL-SCALE OVE RRANGE
Positive Full-Scale Overrange is the amount of overhead avail-
able to handle input voltages greater than +V
REF
( for example,
noise peaks or excess voltages due to system gain errors in
system calibration routines) without introducing errors due to
overloading the analog modulator or overflowing the digital
filter. It is expressed in millivolts.
NE GAT IVE FULL-SCALE OVE RRANGE
T his is the amount of overhead available to handle voltages
below –V
REF
without overloading the analog modulator or
overflowing the digital filter. Note that the analog input will
accept negative voltage peaks even in the unipolar mode. T he
overhead is expressed in millivolts.
HI-Z
DB15
DB14
DB1
DB0
HI-Z
SCLK
SDATA
CLKIN
CS
HI-Z
t
7
t
6
t
5
t
9
t
4
t
8
Figure 5. SSC Mode Timing Diagram
HI-Z
START
DB8
DB9
DB7
STOP 1
STOP 2
HI-Z
HIGH BYTE
LOW BYTE
SDATA
SCLK
DRDY
CS
t
17
t
18
t
19
Figure 6. AC Mode Timing Diagram