a
FEATURES
Dynamic Range: 88.5 dB
Resolution: 0.375 dB
On-Chip Data Latches
+5 V Operation
AD7111A Pin Compatible with AD7524
Low Power
APPLICATIONS
Audio Attenuators
Sonar Systems
Function Generators
Digitally Controlled AGC System
LC MOS LOGDAC
Logarithmic D/A Converter
AD7111/AD7111A
FUNCTIONAL BLOCK DIAGRAMS
V
DD
V
IN
R
FB
2
AD7111
17-BIT DAC
I
OUT
AGND
17-BIT LATCH
DECODE LOGIC
The LOGDAC
®
AD7111/AD7111A are monolithic multiplying
D/A converters featuring wide dynamic range in a small pack-
age. Both DACs can attenuate an analog input signal over the
range 0 dB to 88.5 dB in 0.375 dB steps. They are available in
16-pin DIPs and SOIC packages. The AD7111 is also available
in a 20-terminal LCCC package.
The degree of attenuation across the DAC is determined by an
8-bit word applied to the onboard decode logic. This 8-bit word
is decoded into a 17-bit word which is then applied to a 17-bit
R-2R ladder. The very fine step resolution, which is available
over the entire dynamic range, is due to the use of this 17-bit
DAC.
The AD7111/AD7111A are easily interfaced to a standard 8-bit
MPU bus via an 8-bit data port and standard microprocessor
control lines. The AD7111
WR
input is edge triggered and re-
quires a rising edge to load new data to the DAC. The AD7111A
WR
is level triggered to allow transparent operation of the
latches, if required. It should also be noted that the AD7111A is
exactly pin and function-compatible with the AD7524, an in-
dustry standard 8-bit multiplying DAC. This allows an easy up-
grading of existing AD7524 designs which would benefit both
from the wider dynamic range and the finer step resolution of-
fered by the AD7111A.
The AD7111/AD7111A are fabricated in Linear Compatible
CMOS (LC
2
MOS), an advanced, mixed technology process that
combines precision bipolar circuits with low power CMOS logic.
LOGDAC is a registered trademark of Analog Devices, Inc.
GENERAL DESCRIPTION
CONTROL LOGIC
8-BIT BUFFER
CS
V
DD
WR
D0 – D7
DGND
V
IN
R
FB
AD7111A
17-BIT DAC
I
OUT
AGND
17-BIT LATCH
DECODE LOGIC
CONTROL LOGIC
8-BIT BUFFER
CS
WR
D0 – D7
DGND
PRODUCT HIGHLIGHTS
1. Wide Dynamic Range: 0 dB to 88.5 dB attenuation range in
0.375 dB steps.
2. Small Package: The AD7111/AD7111A are available in
16-pin DIPs and SOIC packages.
3. Transparent Latch Operation: By tying the
CS
and
WR
in-
puts low, the DAC latches in the AD7111A can be made
transparent.
4. Fast Microprocessor Interface: Data setup times of 25 ns and
write pulse width of 57 ns make the AD7111A compatible
with modern microprocessors.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
AD7111–ELECTRICAL CHARACTERISTICS
Parameter
NOMINAL RESOLUTION
ACCURACY RELATIVE TO
0 dB ATTENUATION
0.375 dB Steps:
Accuracy
≤ ±
0.17 dB
Monotonic
0.75 dB Steps:
Accuracy
≤ ±
0.35 dB
Monotonic
1.5 dB Steps:
Accuracy
≤ ±
0.7 dB
Monotonic
3.0 dB Steps:
Accuracy
≤ ±
1.4 dB
Monotonic
6.0 dB Steps:
Accuracy
≤ ±
2.7 dB
Monotonic
GAIN ERROR
V
IN
INPUT RESISTANCE
R
FB
INPUT RESISTANCE
DIGITAL INPUTS
V
IH
(Input High Voltage)
V
IL
(Input Low Voltage)
Input Leakage Current
SWITCHING CHARACTERISTICS
1
t
CS
t
CH
t
WR
t
DS
t
DH
t
RFSH
POWER SUPPLY
V
DD
I
DD
AD7111L/C/U Grades
T
A
= +25 C T
A
= T
MIN
, T
MAX
0.375
0.375
AD7111/AD7111A–SPECIFICATIONS
V, V
(V = +5
DD
= –10 V dc, I
OUT
= AGND = DGND = O V output amplifier
AD711 except where noted)
IN
AD7111K/B/T Grades
T
A
= +25 C T
A
= T
MIN
, T
MAX
0.375
0.375
Units
dB
Conditions/Comments
0 to 36
0 to 54
0 to 48
0 to 72
0 to 54
Full Range
0 to 66
Full Range
0 to 72
Full Range
±
0.1
9/11/15
0 to 36
0 to 54
0 to 42
0 to 66
0 to 48
0 to 78
0 to 54
Full Range
0 to 60
Full Range
±
0.15
9/11/15
0 to 30
0 to 48
0 to 42
0 to 72
0 to 42
0 to 85.5
0 to 60
Full Range
0 to 60
Full Range
±
0.15
7/11/18
0 to 30
0 to 48
0 to 36
0 to 60
0 to 42
0 to 72
0 to 48
Full Range
0 to 48
Full Range
±
0.20
7/11/18
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB max
kΩ min/typ/max
kΩ min/typ/max
V min
V max
µA
max
ns min
ns min
ns min
ns min
ns min
µs
min
V
mA max
µA
max
Guaranteed Attenuation Ranges
for Specified Step Sizes
Full Range Is from 0 dB
to 88.5 dB
9.3/11.5/15.7 9.3/11.5/15.7
2.4
0.8
±
1
0
0
350
175
10
3
+5
1
500
2.4
0.8
±
10
0
0
500
250
10
4.5
+5
4
1000
7.3/11.5/18.8 7.3/11.5/18.8
2.4
0.8
±
1
0
0
350
175
10
3
+5
1
500
2.4
0.8
±
10
0
0
500
250
10
4.5
+5
4
1000
Digital Inputs = V
DD
Chip Select to Write Setup Time
Chip Select to Write Hold Time
Write Pulse Width
Data Valid to Write Setup Time
Data Valid to Write Hold Time
Refresh Time
Digital Inputs = V
IL
or V
IH
Digital Inputs = 0 V or V
DD
;
See Figure 6
NOTE
1
Sample tested at +25°C to ensure compliance.
Specifications subject to change without notice.
AC PERFORMANCE CHARACTERISTICS
These characteristics are included for design guidance only and are not subject
to test. V
DD
= +5 V, V
IN
= –10 V dc except where noted, I
OUT
= AGND = DGND = O V, output amplifier AD711 except where noted.
Parameter
DC Supply Rejection,
∆Gain/∆V
DD
Propagation Delay
Digital-to-Analog Glitch Impulse
AD7111L/C/U Grades
T
A
= +25 C T
A
= T
MIN
, T
MAX
0.001
3.0
100
0.005
4.5
AD7111K/B/T Grades
T
A
= +25 C T
A
= T
MIN
, T
MAX
Units
0.001
3.0
100
0.005
4.5
Conditions/Comments
dB per % max
∆V
DD
=
±
10%, Input Code = 00000000
µs
max
Full-Scale Change Measured from
WR
Going High,
CS
= 0 V
nV secs typ
Measured with AD843 as Output
Amplifier for Code Transition
10000000 to 00000000
C1 of Figure 1 is 0 pF
pF max
pF max
dB max
dB typ
V
IN
= 6 V rms at 1 kHz
nV/√Hz max
Includes AD711 Amplifier Noise
pF max
Output Capacitance, Pin 1
Input Capacitance, Pin 15 and Pin 16
Feedthrough at 1 kHz
Total Harmonic Distortion
Output Noise Voltage Density
Digital Input Capacitance
185
7
–94
–91
70
7
185
7
–72
–91
70
7
185
7
–94
–91
70
7
185
7
–68
–91
70
7
Specifications subject to change without notice.
–2–
REV. 0
AD7111/AD7111A
AD7111A–ELECTRICAL CHARACTERISTICS
Parameter
NOMINAL RESOLUTION
ACCURACY RELATIVE TO
0 dB ATTENUATION
0.375 dB Steps:
Accuracy
≤ ±
0.17 dB
Monotonic
0.75 dB Steps:
Accuracy
≤ ±
0.35 dB
Monotonic
1.5 dB Steps:
Accuracy
≤ ±
0.7 dB
Monotonic
3.0 dB Steps:
Accuracy
≤ ±
1.4 dB
Monotonic
6.0 dB Steps:
Accuracy
≤ ±
2.7 dB
Monotonic
GAIN ERROR
V
IN
INPUT RESISTANCE
R
FB
INPUT RESISTANCE
DIGITAL INPUTS
V
IH
(Input High Voltage)
V
IL
(Input High Voltage)
Input Leakage Current
SWITCHING CHARACTERISTICS
t
CS
t
CH
t
WR
t
DS
t
DH
POWER SUPPLY
V
DD
I
DD
1
(V
DD
= +5 V, V
IN
= –10 V dc, I
OUT
= AGND = DGND = O V output amplifier
AD711 except where noted)
Units
dB
Conditions/Comments
AD7111AC Grade
T
A
= +25 C T
A
= T
MIN
, T
MAX
0.375
0.375
AD7111AB Grade
T
A
= +25 C T
A
= T
MIN
, T
MAX
0.375
0.375
0 to 36
0 to 54
0 to 48
0 to 72
0 to 54
Full Range
0 to 66
Full Range
0 to 72
Full Range
±
0.1
9/11/15
0 to 36
0 to 54
0 to 42
0 to 66
0 to 48
0 to 78
0 to 54
Full Range
0 to 60
Full Range
±
0.15
9/11/15
0 to 30
0 to 48
0 to 42
0 to 72
0 to 48
0 to 85.5
0 to 60
Full Range
0 to 60
Full Range
±
0.15
7/11/18
0 to 30
0 to 48
0 to 36
0 to 60
0 to 42
0 to 72
0 to 48
Full Range
0 to 48
Full Range
±
0.20
7/11/18
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB min
dB max
kΩ min/typ/max
kΩ min/typ/max
V min
V max
µA
max
ns min
ns min
ns min
ns min
ns min
V
mA max
mA max
Guaranteed Attenuation Ranges
for Specified Step Sizes
Full Range Is from 0 dB
to 88.5 dB
9.3/11.5/15.7 9.3/11.5/15.7
2.4
0.8
±
1
0
0
57
25
10
+5
1
1
2.4
0.8
±
10
0
0
57
25
10
+5
2
1
7.3/11.5/18.8 7.3/11.5/18.8
2.4
0.8
±
1
0
0
57
25
10
+5
1
1
2.4
0.8
±
10
0
0
57
25
10
+5
2
1
Digital Inputs = V
DD
Chip Select to Write Setup Time
Chip Select to Write Hold Time
Write Pulse Width
Data Valid to Write Setup Time
Data Valid to Write Hold Time
Digital Inputs = V
IL
or V
IH
CS
=
WR
= 0 V
Digital Inputs = 0 V or V
DD
;
See Figure 6
NOTE
1
Sample tested at +25°C to ensure compliance.
Specifications subject to change without notice.
AC PERFORMANCE CHARACTERISTICS
These characteristics are included for design guidance only and are not subject
to test. V
DD
= +5 V, V
IN
= –10 V dc except where noted, I
OUT
= AGND = DGND = O V, output amplifier AD711 except where noted.
Parameter
DC Supply Rejection,
∆Gain/∆V
DD
Propagation Delay
Digital-to-Analog Glitch Impulse
AD7111AC Grade
T
A
= +25 C T
A
= T
MIN
, T
MAX
0.001
1
10
0.005
1.5
20
AD7111AB Grade
T
A
= +25 C T
A
= T
MIN
, T
MAX
Units
0.001
1
10
0.005
1.5
20
Conditions/Comments
dB per % max
∆V
DD
=
±
10%, Input Code = 00000000
µs
max
Full-Scale Change Measured from
WR
Going High,
CS
= 0 V
nV secs typ
Measured with AD843 as Output
Amplifier for Code Transition
10000000 to 00000000
C1 of Figure 1 is 0 pF
pF max
pF max
dB max
dB typ
V
IN
= 6 V rms at 1 kHz
nV/√Hz max
Includes AD711 Amplifier Noise
pF max
Output Capacitance, Pin 1
Input Capacitance, Pin 15 and Pin 16
Feedthrough at 1 kHz
Total Harmonic Distortion
Output Noise Voltage Density
Digital Input Capacitance
50
7
–94
–91
70
7
50
7
–90
–91
70
7
50
7
–92
–91
70
7
50
7
–90
–91
70
7
Specifications subject to change without notice.
REV. 0
–3–
AD7111/AD7111A
ABSOLUTE MAXIMUM RATINGS*
(T
A
= +25°C unless otherwise noted)
V
DD
(to DGND) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7 V
V
IN
(to AGND) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
35 V
Digital Input Voltage to DGND . . . . . –0.3 V to V
DD
+ 0.3 V
I
OUT
to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to V
DD
V
RFB
to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
35 V
AGND to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to V
DD
DGND to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to V
DD
Power Dissipation, DIP . . . . . . . . . . . . . . . . . . . . . . . . . . 1 W
θ
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . 117°C/W
Lead Temperature (Soldering, 10 secs) . . . . . . . . . +300°C
Power Dissipation, SOIC . . . . . . . . . . . . . . . . . . . . . . . . . 1 W
θ
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 75°C/W
Lead Temperature (Soldering)
Vapor Phase (60 secs) . . . . . . . . . . . . . . . . . . . . . . . 215°C
Infrared (15 secs) . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
Power Dissipation, LCCC . . . . . . . . . . . . . . . . . . . . . . . . 1 W
θ
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 76°C/W
Lead Temperature (Soldering, 10 secs) . . . . . . . . . +300°C
Operating Temperature Range
Commercial (K, L Versions) . . . . . . . . . . . . . 0°C to +70°C
Industrial (B, C Versions) . . . . . . . . . . . . . –40°C to +85°C
Extended (T, U Versions) . . . . . . . . . . . . –55°C to +125°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
*Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. This is a stress rating only, and functional
operation of the device at these or any other conditions above those listed in the
operational sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD7111/AD7111A features proprietary ESD protection circuitry, permanent
damage may occur on devices subjected to high energy electrostatic discharges. Therefore,
proper ESD precautions are recommended to avoid performance degradation or loss of
functionality.
WARNING!
ESD SENSITIVE DEVICE
ORDERING GUIDES
AD7111A ORDERING GUIDE
AD7111 ORDERING GUIDE
Model
AD7111ABN
AD7111ACN
AD7111ABR
AD7111ACR
Temperature
Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
Specified
Accuracy
Range
0 dB to 60 dB
0 dB to 72 dB
0 dB to 60 dB
0 dB to 72 dB
Package
Option
1
N-16
N-16
R-16
R-16
Specified
Temperature
Accuracy
l
Model
Range
Range
AD7111KN
0°C to +70°C
0 dB to 60 dB
AD7111BQ
–40°C to +85°C 0 dB to 60 dB
AD7111LN
0°C to +70°C
0 dB to 72 dB
AD7111CQ
–40°C to +85°C 0 dB to 72 dB
AD7111UQ/883B –55°C to +125°C 0 dB to 72 dB
AD7111TE/883B –55°C to +125°C 0 dB to 60 dB
Package
Option
2
N-16
Q-16
N-16
Q-16
Q-16
E-20A
NOTE
1
N = Plastic DIP; R = SOIC.
NOTES
1
To order MIL-STD-883B, Class B processed parts, add /883B to part number.
Contact local sales office for military data sheet and availability.
2
N = Plastic DIP; Q = Cerdip; E = LCCC; R = SOIC.
TERMINOLOGY
RESOLUTION:
Nominal change in attenuation when moving
between two adjacent codes.
MONOTONICITY:
The device is monotonic if the analog out-
put decreases (or remains constant) as the digital code increases.
FEEDTHROUGH ERROR:
That portion of the input signal
which reaches the output when all digital inputs are high. See
section on Applications.
OUTPUT LEAKAGE CURRENT:
Current which appears on
the I
OUT
terminal with all digital inputs high.
TOTAL HARMONIC DISTORTION:
A measure of the
harmonics introduced by the circuit when a pure sinusoid is
applied to the input. It is expressed as the harmonic energy
divided by the fundamental energy at the output.
ACCURACY:
The difference (measured in dB) between the
ideal transfer function as listed in Table I and the actual transfer
function as measured with the device.
OUTPUT CAPACITANCE:
Capacitance from I
OUT
to
ground.
DIGITAL-TO-ANALOG GLITCH IMPULSE:
The amount
of charge injected from the digital inputs to the analog output
when the inputs change state. This is normally specified as the
area of the glitch in either pA-secs or nV-secs depending upon
whether the glitch is measured as a current or voltage signal.
Glitch impulse is measured with V
IN
= AGND.
PROPAGATION DELAY:
This is a measure of the internal
delays of the circuit and is defined as the time from a digital in-
put change to the analog output current reaching 90% of its
final value.
–4–
REV. 0
AD7111/AD7111A
PIN CONFIGURATIONS
DIP/SOIC
LCCC
Write Cycle Timing Diagram
CIRCUIT DESCRIPTION
GENERAL CIRCUIT DESCRIPTION
The AD7111/AD7111A consists of a 17-bit R-2R CMOS mul-
tiplying D/A converter with extensive digital logic. The logic
translates the 8-bit binary input into a 17-bit word which is
used to drive the D/A converter. Input data on the D7-D0 bus
is loaded into the input data latches using
CS
and
WR
control
signals. When using the AD7111, the rising edge of
WR
latches
the input data and initiates the internal data transfer to the de-
coder. A minimum time t
RFSH
, the refresh time, is required for
the data to propagate through the decoder before a new data
write is attempted.
In contrast, the AD7111A
WR
input is level triggered to allow
transparent operation of the latches if required.
The transfer function for the circuit of Figure 1 is given by:
V
O
=
–V
IN
10
exp
–
0. 375
N
20
where 0.375 is the step size (resolution) in dB and N is the in-
put code in decimal for values 0 to 239. For 240
≤
N
≤
255 the
output is zero. Table I gives the output attenuation relative to
0 dB for all possible input codes.
Figure 1. Typical Circuit Configuration
or
V
O
V
IN
dB
= –0.375
N
The graphs on the last page give a pictorial representation of the
specified accuracy and monotonic ranges for all grades of the
AD7111/AD7111A. High attenuation levels are specified with
less accuracy than low attenuation levels. The range of mono-
tonic behavior depends upon the attenuation step size used.
Table I. Ideal Attenuation in dB vs. Input Code
D3-D0
D7-D4
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
0000
0.0
6.0
12.0
18.0
24.0
30.0
36.0
42.0
48.0
54.0
60.0
66.0
72.0
78.0
84.0
MUTE
0001
0.375
6.375
12.375
18.375
24.375
30.375
36.375
42.375
48.375
54.375
60.375
66.375
72.375
78.375
84.375
MUTE
0010
0.75
6.75
12.75
18.75
24.75
30.75
36.75
42.75
48.75
54.75
60.75
66.75
72.75
78.75
84.75
MUTE
0011
1.125
7.125
13.125
19.125
25.125
31.125
37.125
43.125
49.125
55.125
61.125
67.125
73.125
79.125
85.125
MUTE
0100
1.5
7.5
13.5
19.5
25.5
31.5
37.5
43.5
49.5
55.5
61.5
67.5
73.5
79.5
85.5
MUTE
0101
1.875
7.875
13.875
19.875
25.875
31.875
37.875
43.875
49.875
55.875
61.875
67.875
73.875
79.875
85.875
MUTE
0110
2.25
8.25
14.25
20.25
26.25
32.25
38.25
44.25
50.25
56.25
62.25
68.25
74.25
80.25
86.25
MUTE
0111
2.625
8.625
14.625
20.625
26.625
32.625
38.625
44.625
50.625
56.625
62.625
68.625
74.625
80.625
86.625
MUTE
1000
3.0
9.0
15.0
21.0
27.0
33.0
39.0
45.0
51.0
57.0
63.0
69.0
75.0
81.0
87.0
MUTE
1001
3.375
9.375
15.375
21.375
27.375
33.375
39.375
45.375
51.375
57.375
63.375
69.375
75.375
81.375
87.375
MUTE
1010
3.75
9.75
15.75
21.75
27.75
33.75
39.75
45.75
51.75
57.75
63.75
69.75
75.75
81.75
87.75
MUTE
1011
4.125
10.125
16.125
22.125
28.125
34.125
40.125
46.125
52.125
58.125
64.125
70.125
76.125
82.125
88.125
MUTE
1100
4.5
10.5
16.5
22.5
28.5
34.5
40.5
46.5
52.5
58.5
64.5
70.5
76.5
82.5
88.5
MUTE
1101
4.875
10.875
16.875
22.875
28.875
34.875
40.875
46.875
52.875
58.875
64.875
70.875
76.875
82.875
88.875
MUTE
1110
5.25
11.25
17.25
23.25
29.25
35.25
41.25
47.25
53.25
59.25
65.25
71.25
77.25
83.25
89.25
MUTE
1111
5.625
11.625
17.625
23.625
29.625
35.625
41.625
47.625
53.625
59.625
65.625
71.625
77.625
83.625
89.625
MUTE
REV. 0
–5–
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