Analog Devices AD526 Datasheet
Software Programmable
a
FEATURES
Digitally Programmable Binary Gains from 1 to 16
Two-Chip Cascade Mode Achieves Binary Gain from
1 to 256
Gain Error:
0.01% Max, Gain = 1, 2, 4 (C Grade)
0.02% Max, Gain = 8, 16 (C Grade)
0.5 ppm/ⴗC Drift Over Temperature
Fast Settling Time
10 V Signal Change:
0.01% in 4.5 s (Gain = 16)
Gain Change:
0.01% in 5.6 s (Gain = 16)
Low Nonlinearity: ⴞ0.005% FSR Max (J Grade)
Excellent DC Accuracy:
Offset Voltage: 0.5 mV Max (C Grade)
Offset Voltage Drift: 3 V/ⴗC (C Grade)
TTL-Compatible Digital Inputs
PRODUCT DESCRIPTION
The AD526 is a single-ended, monolithic software programmable gain amplifier (SPGA) that provides gains of 1, 2, 4, 8
and 16. It is complete, including amplifier, resistor network
and TTL-compatible latched inputs, and requires no external
components.
Low gain error and low nonlinearity make the AD526 ideal for
precision instrumentation applications requiring programmable
gain. The small signal bandwidth is 350 kHz at a gain of 16. In
addition, the AD526 provides excellent dc precision. The FETinput stage results in a low bias current of 50 pA. A guaranteed
maximum input offset voltage of 0.5 mV max (C grade) and low
gain error (0.01%, G = 1, 2, 4, C grade) are accomplished using
Analog Devices’ laser trimming technology.
To provide flexibility to the system designer, the AD526 can be
operated in either latched or transparent mode. The force/sense
configuration preserves accuracy when the output is connected
to remote or low impedance loads.
The AD526 is offered in one commercial (0°C to +70°C) grade,
J, and three industrial grades, A, B and C, which are specified
from –40°C to +85°C. The S grade is specified from –55°C to
+125°C. The military version is available processed to MIL-
STD 883B, Rev C. The J grade is supplied in a 16-lead plastic
DIP, and the other grades are offered in a 16-lead hermetic
side-brazed ceramic DIP.
Gain Amplifier
AD526
PIN CONFIGURATION
DIG GND A1
ANALOG GND 2 A2
ANALOG GND 1 B
V
OUT
1
NULL A0
2
V
3
IN
NULL
4
AD526
TOP VIEW
5
(Not to Scale)
6
–V
7
S
SENSE V
8
APPLICATION HIGHLIGHTS
1. Dynamic Range Extension for ADC Systems: A single
AD526 in conjunction with a 12-bit ADC can provide
96 dB of dynamic range for ADC systems.
2. Gain Ranging Preamps: The AD526 offers complete digital
gain control with precise gains in binary steps from 1 to 16.
Additional gains of 32, 64, 128 and 256 are possible by cascading two AD526s.
ORDERING GUIDE
Model Range Descriptions Options
AD526JN Commercial 16-Lead Plastic DIP N-16
AD526AD Industrial 16-Lead Cerdip D-16
AD526BD Industrial 16-Lead Cerdip D-16
AD526CD Industrial 16-Lead Cerdip D-16
AD526SD Military 16-Lead Cerdip D-16
AD526SD/883B Military 16-Lead Cerdip D-16
5962-9089401MEA* Military 16-Lead Cerdip D-16
*Refer to official DESC drawing for tested specifications.
Temperature Package Package
16
15
14
CS
13
CLK
12
11
+V
10
S
FORCE
9
OUT
REV. D
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: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 1999
AD526–SPECIFICATIONS
(@ VS = ⴞ15 V, RL = 2 k⍀ and TA = +25ⴗC unless otherwise noted)
AD526J AD526A AD526B/S AD526C
Model Min Typ Max Min Typ Max Min Typ Max Min Typ Max Units
GAIN
Gain Range
(Digitally Programmable) 1, 2, 4, 8, 16 1, 2, 4, 8, 16 1, 2, 4, 8, 16 1, 2, 4, 8, 16
Gain Error
Gain = 1 0.05 0.02 0.01 0.01 %
Gain = 2 0.05 0.03 0.02 0.01 %
Gain = 4 0.10 0.03 0.02 0.01 %
Gain = 8 0.15 0.07 0.04 0.02 %
Gain = 16 0.15 0.07 0.04 0.02 %
Gain Error Drift
Over Temperature
G = 1 0.5 2.0 0.5 2.0 0.5 2.0 0.5 2.0 ppm/°C
G = 2 0.5 2.0 0.5 2.0 0.5 2.0 0.5 2.0 ppm/°C
G = 4 0.5 3.0 0.5 3.0 0.5 3.0 0.5 3.0 ppm/°C
G = 8 0.5 5.0 0.5 5.0 0.5 5.0 0.5 5.0 ppm/°C
G = 16 1.0 5.0 1.0 5.0 1.0 5.0 1.0 5.0 ppm/°C
Gain Error (T
MIN
to T
MAX
)
Gain = 1 0.06 0.03 0.02 0.015 %
Gain = 2 0.06 0.04 0.03 0.015 %
Gain = 4 0.12 0.04 0.03 0.015 %
Gain = 8 0.17 0.08 0.05 0.03 %
Gain = 16 0.17 0.08 0.05 0.03 %
Nonlinearity
Gain = 1 0.005 0.005 0.005 0.0035 % FSR
Gain = 2 0.001 0.001 0.001 0.001 % FSR
Gain = 4 0.001 0.001 0.001 0.001 % FSR
Gain = 8 0.001 0.001 0.001 0.001 % FSR
Gain = 16 0.001 0.001 0.001 0.001 % FSR
Nonlinearity (T
MIN
to T
MAX
)
Gain = 1 0.01 0.01 0.01 0.007 % FSR
Gain = 2 0.001 0.001 0.001 0.001 % FSR
Gain = 4 0.001 0.001 0.001 0.001 % FSR
Gain = 8 0.001 0.001 0.001 0.001 % FSR
Gain = 16 0.001 0.001 0.001 0.001 % FSR
VOLTAGE OFFSET, ALL GAINS
Input Offset Voltage 0.4 1.5 0.25 0.7 0.25 0.5 0.25 0.5 mV
Input Offset Voltage Drift Over
Temperature 5 20 3 10 3 10 3 10 µV/°C
Input Offset Voltage
to T
T
MIN
MAX
2.0 1.0 0.8 0.8 mV
Input Offset Voltage vs. Supply
(V
± 10%) 80 80 84 90 dB
S
INPUT BIAS CURRENT
Over Input Voltage Range ± 10 V 50 150 50 150 50 150 50 150 pA
ANALOG INPUT
CHARACTERISTICS
Voltage Range
(Linear Operation) ⴞ10 ±12 ⴞ10 ±12 ⴞ10 ±12 ⴞ10 ±12 V
Capacitance 5555pF
RATED OUTPUT
Voltage ⴞ10 ±12 ⴞ10 ±12 ⴞ10 ±12 ⴞ10 ±12 V
Current (V
= ±10 V) ±10 ⴞ5 ±10 ⴞ5 ±10 ⴞ5 ±10 mA
OUT
Short-Circuit Current 15 30 15 30 15 30 15 30 mA
DC Output Resistance 0.002 0.002 0.002 0.002 Ω
Load Capacitance
(For Stable Operation) 700 700 700 700 pF
–2–
REV. D
AD526
Model Min Typ Max Min Typ Max Min Typ Max Min Typ Max Units
AD526J AD526A AD526B/S AD526C
NOISE, ALL GAINS
Voltage Noise, RTI
0.1 Hz to 10 Hz 3 3 3 3 µV p-p
Voltage Noise Density, RTI
f = 10 Hz 70 70 70 70 nV√Hz
f = 100 Hz 60 60 60 60 nV√Hz
f = 1 kHz 30 30 30 30 nV√Hz
f = 10 kHz 25 25 25 35 nV√Hz
DYNAMIC RESPONSE
–3 dB Bandwidth (Small Signal)
G = 1 4.0 4.0 4.0 4.0 MHz
G = 2 2.0 2.0 2.0 2.0 MHz
G = 4 1.5 1.5 1.5 1.5 MHz
G = 8 0.65 0.65 0.65 0.65 MHz
G = 16 0.35 0.35 0.35 0.35 MHz
Signal Settling Time to 0.01%
= ±10 V)
(∆V
OUT
G = 1 2.1 4 2.1 4 2.1 4 2.1 4 µs
G = 2 2.5 5 2.5 5 2.5 5 2.5 5 µs
G = 4 2.7 5 2.7 5 2.7 5 2.7 5 µs
G = 8 3.6 7 3.6 7 3.6 7 3.6 7 µs
G = 16 4.1 7 4.1 7 4.1 7 4.1 7 µs
Full Power Bandwidth
G = 1, 2, 4 0.10 0.10 0.10 0.10 MHz
G = 8, 16 0.35 0.35 0.35 0.35 MHz
Slew Rate
G = 1, 2, 4 4 6 4 6 4 6 4 6V/µs
G = 8, 16 18 24 18 24 18 24 18 24 V/µs
DIGITAL INPUTS
to T
(T
MIN
Input Current (V
MAX
)
= 5 V) 60 100 140 60 100 140 60 100 140 60 100 140 µA
H
Logic “1” 2 6 2 6 2 6 2 6 V
Logic “0” 0 0.8 0 0.8 0 0.8 0 0.8 V
TIMING
1
(VL = 0.2 V, VH = 3.7 V)
A0, A1, A2
T
C
T
S
T
H
50 50 50 50 ns
30 30 30 30 ns
30 30 30 30 ns
B
T
C
T
S
T
H
50 50 50 50 ns
40 40 40 40 ns
10 10 10 30 ns
TEMPERATURE RANGE
Specified Performance 0 +70 –40 +85 –40/–55 +85/+125 –40 +85 °C
Storage –65 +125 –65 +150 –65 +150 –65 +150 °C
POWER SUPPLY
Operating Range ⴞ4.5 ⴞ16.5 ⴞ4.5 ⴞ16.5 ⴞ4.5 ⴞ16.5 ⴞ4.5 ⴞ16.5 V
Positive Supply Current 10 14 10 14 10 14 10 14 mA
Negative Supply Current 10 13 10 13 10 13 10 13 mA
PACKAGE OPTIONS
Plastic (N-16) AD526JN
Ceramic DIP (D-16) AD526AD AD526BD AD526SD AD526CD
AD526SD/883B
NOTES
1
Refer to Figure 25 for definitions. FSR = Full Scale Range = 20 V. RTI = Referred to Input.
Specifications subject to change without notice.
Specifications shown in boldface are tested on all production units at final electrical test. All min and max specifications are guaranteed, although only those shown in
boldface are tested on all production units.
REV. D
–3–
AD526–Typical Performance Characteristics
20
15
10
5
OUTPUT VOLTAGE SWING – 6V
0
05 20
+258C
R
= 2kV
L
SUPPLY VOLTAGE – 6V
10 15
Figure 1. Output Voltage Swing vs.
Supply Voltage, G = 16
100nA
10nA
1nA
100pA
INPUT BIAS CURRENT
10pA
30
20
10
OUTPUT VOLTAGE SWING – 6V
0
100 1k 10k
LOAD RESISTANCE – V
@ VS = 615V
Figure 2. Output Voltage Swing vs.
Load Resistance
75
VS = 615V
50
25
INPUT BIAS CURRENT – pA
20
15
VIN = 0
10
5
INPUT BIAS CURRENT – pA
0
05 20
SUPPLY VOLTAGE – 6V
10 15
Figure 3. Input Bias Current vs.
Supply Voltage
20
10
GAIN
1
16
4
2
8
1
1pA
–60 –20 140
20 60 100
TEMPERATURE – 8C
Figure 4. Input Bias Current vs.
Temperature
25
20
15
10
5
FULL POWER RESPONSE – V p-p
0
1k
GAIN = 1, 2, 4
10k 100k 1M 10M
FREQUENCY – Hz
GAIN = 8, 16
Figure 7. Large Signal Frequency
Response
0
–10
–5 0 5 10
INPUT VOLTAGE – V
Figure 5. Input Bias Current vs. Input
Voltage
100
80
60
40
20
POWER SUPPLY REJECTION – dB
10
10 100 1k 10k 100k 1M
1
FREQUENCY – Hz
615V WITH 1V p-p
SINE WAVE
–SUPPLY
+SUPPLY
Figure 8. PSRR vs. Frequency
10 100 10M
1k 10k 100k 1M
FREQUENCY – Hz
Figure 6. Gain vs. Frequency
1.0002
1.0001
1.0000
NORMALIZED GAIN
0.9999
0.9998
–60
–20 20 60 100 140
TEMPERATURE – 8C
Figure 9. Normalized Gain vs.
Temperature, Gain = 1
–4–
REV. D
AD526
1000
100
INPUT NOISE VOLTAGE – nV/ Hz
10
10 100k100
1k
FREQUENCY – Hz
10k
Figure 10. Noise Spectral Density
0.006
0.004
0.002
0.000
NONLINEARITY – %FSR
–0.002
–0.004
–60
–20 20 60 100 140
TEMPERATURE – 8C
Figure 11. Nonlinearity vs.
Temperature, Gain = 1
Figure 12. Wideband Output Noise,
G = 16 (Amplified by 10)
Figure 13. Large Signal Pulse
Response and Settling Time,*
G = 1
Figure 16. Small Signal Pulse
Response, G = 2
Figure 14. Small Signal Pulse
Response, G = 1
Figure 17. Large Signal Pulse
Response and Settling Time,*
G = 4
Figure 15. Large Signal Pulse
Response and Settling Time,*
G = 2
Figure 18. Small Signal Pulse
Response, G = 4
*For Settling Time Traces, 0.01% = 1/2 Vertical Division
REV. D
–5–
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