12112714

Dual, Low Noise, Single-Supply
Variable Gain Amplifier
AD605
FUNCTIONAL BLOCK DIAGRAM
FEATURES
VGN
VREF
GAIN
CONTROL
AND
SCALING
PRECISION PASSIVE
INPUT ATTENUATOR
FIXED GAIN
AMPLIFIER
+34.4dB
OUT
FBK
VOCM
+IN
–IN
DIFFERENTIAL
ATTENUATOR
0 TO –48.4dB
AD605
00541-001
2 independent linear-in-dB channels
Input noise at maximum gain: 1.8 nV/√Hz, 2.7 pA/√Hz
Bandwidth: 40 MHz (−3 dB)
Differential input
Absolute gain range programmable
−14 dB to +34 dB (FBK shorted to OUT) through
0 dB to 48 dB (FBK open)
Variable gain scaling: 20 dB/V through 40 dB/V
Stable gain with temperature and supply variations
Single-ended unipolar gain control
Output common mode independently set
Power shutdown at lower end of gain control
Single 5 V supply
Low power: 90 mW/channel
Drives ADCs directly
Figure 1.
APPLICATIONS
Ultrasound and sonar time-gain controls
High performance AGC systems
Signal measurement
GENERAL DESCRIPTION
The AD605 is a low noise, accurate, dual-channel, linear-in-dB
variable gain amplifier (VGA), optimized for any application
requiring high performance, wide bandwidth variable gain
control. Operating from a single 5 V supply, the AD605 provides
differential inputs and unipolar gain control for ease of use.
Added flexibility is achieved with a user-determined gain range
and an external reference input that provide user-determined
gain scaling (dB/V).
Each independent channel of the AD605 provides a gain range
of 48 dB that can be optimized for the application. Gain ranges
between −14 dB to +34 dB and 0 dB to +48 dB can be selected
by a single resistor between Pin FBK and Pin OUT. The lower
and upper gain ranges are determined by shorting Pin FBK to
Pin OUT or leaving Pin FBK unconnected, respectively. The
two channels of the AD605 can be cascaded to provide 96 dB
of very accurate gain range in a monolithic package.
The high performance linear-in-dB response of the AD605 is
achieved with the differential input, single-supply, exponential
amplifier (DSX-AMP) architecture. Each of the DSX-AMPs
comprises a variable attenuator of 0 dB to −48.4 dB followed by
a high speed, fixed-gain amplifier. The attenuator is based on a
7-stage R-1.5R ladder network. The attenuation between tap
points is 6.908 dB, and 48.360 dB for the entire ladder network.
The DSX-AMP architecture results in 1.8 nV/√Hz input noise
spectral density and accepts a ±2.0 V input signal when VOCM
is biased at VP/2.
The gain control interface provides an input resistance of
approximately 2 MΩ and scale factors from 20 dB/V to 30 dB/V
for a VREF input voltage of 2.5 V to 1.67 V, respectively. Note
that scale factors up to 40 dB/V are achievable with reduced
accuracy for scales above 30 dB/V. The gain scales linearly in dB
with control voltages (VGN) of 0.4 V to 2.4 V for the 20 dB/V
scale and 0.20 V to 1.20 V for the 40 dB/V scale. When VGN is
<50 mV, the amplifier is powered down to draw 1.9 mA. Under
normal operation, the quiescent supply current of each amplifier
channel is only 18 mA.
The AD605 is available in a 16-lead PDIP and a 16-lead SOIC_N
package and is guaranteed for operation over the −40°C to +85°C
temperature range.
Rev. F
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 that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©1996–2008 Analog Devices, Inc. All rights reserved.
AD605
TABLE OF CONTENTS
Features .............................................................................................. 1
Gain Control Interface............................................................... 14
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
Fixed Gain Amplifier and Interpolator Circuits—Applying an
Active Feedback Amplifier ........................................................ 15
General Description ......................................................................... 1
Applications Information .............................................................. 16
Revision History ............................................................................... 2
Connecting Two Amplifiers to Double the Gain Range ....... 16
Specifications..................................................................................... 3
Evaluation Board ............................................................................ 18
Absolute Maximum Ratings............................................................ 5
Input Connections ..................................................................... 18
ESD Caution .................................................................................. 5
Adjusting Gain, Common-Mode, and Reference Levels ...... 18
Pin Configuration and Function Descriptions ............................. 6
Output Connections .................................................................. 18
Typical Performance Characteristics (per Channel) ................... 7
Outline Dimensions ....................................................................... 21
Theory of Operation ...................................................................... 13
Ordering Guide .......................................................................... 22
Differential Ladder (Attenuator) .............................................. 14
AC Coupling ............................................................................... 14
REVISION HISTORY
6/08—Rev. E to Rev. F
Added Evaluation Board Section ................................................. 18
Added Figure 42 and Table 4......................................................... 18
Added Figure 43 and Figure 44..................................................... 19
Added Figure 45 to Figure 50........................................................ 20
7/04—Rev. B to Rev. C
Edits to General Description ...........................................................1
Edits to Specifications .......................................................................2
Edits to Ordering Guide ...................................................................3
Change to TPC 22 .............................................................................6
Updated Outline Dimensions ....................................................... 12
5/07—Rev. D to Rev. E
Changes to Table 1 ............................................................................ 5
Changes to Fixed Gain Amplifier and Interpolator Circuits—
Applying an Active Feedback Amplifier Section........................ 15
Updated Outline Dimensions ....................................................... 18
Changes to Ordering Guide .......................................................... 19
1/06—Rev. C to Rev. D
Updated Format .................................................................. Universal
Changes to Table 2 ............................................................................ 5
Changes to Differential Ladder (Attenuator) Section ............... 14
Updated the Outline Dimensions ................................................ 18
Changes to the Ordering Guide.................................................... 19
Rev. F | Page 2 of 24
AD605
SPECIFICATIONS
Each channel @ TA = 25°C, VS = 5 V, RS = 50 Ω, RL = 500 Ω, CL = 5 pF, VREF = 2.5 V (scaling = 20 dB/V), −14 dB to +34 dB gain range,
unless otherwise noted.
Table 1.
Parameter
INPUT CHARACTERISTICS
Input Resistance
Input Capacitance
Peak Input Voltage
Input Voltage Noise
Input Current Noise
Noise Figure
Common-Mode Rejection Ratio
OUTPUT CHARACTERISTICS
−3 dB Bandwidth
Slew Rate
Output Signal Range
Output Impedance
Output Short-Circuit Current
Harmonic Distortion
HD2
HD3
HD2
HD3
Two-Tone Intermodulation
Distortion (IMD)
1 dB Compression Point
Third-Order Intercept
Channel-to-Channel Crosstalk
Group Delay Variation
VOCM Input Resistance
ACCURACY
Absolute Gain Error
−14 dB to −11 dB
−11 dB to +29 dB
+29 dB to +34 dB
Gain Scaling Error
Output Offset Voltage
Output Offset Variation
Conditions
Min
At minimum gain
VGN = 2.9 V
VGN = 2.9 V
RS = 50 Ω, f = 10 MHz, VGN = 2.9 V
RS = 200 Ω, f = 10 MHz, VGN = 2.9 V
f = 1 MHz, VGN = 2.65 V
Constant with gain
VGN = 1.5 V, output = 1 V step
RL ≥ 500 Ω
f = 10 MHz
VGN = 1 V, VOUT = 1 V p-p
f = 1 MHz
f = 1 MHz
f = 10 MHz
f = 10 MHz
RS = 0 Ω, VGN = 2.9 V, VOUT = 1 V p-p
f = 1 MHz
f = 10 MHz
f = 10 MHz, VGN = 2.9 V, output referred
f = 10 MHz, VGN = 2.9 V,
VOUT = 1 V p-p, input referred
Ch1: VGN = 2.65 V, inputs shorted,
Ch2: VGN = 1.5 V (mid gain),
f = 1 MHz, VOUT = 1 V p-p
1 MHz < f < 10 MHz, full gain range
0.25 V < VGN < 0.40 V
0.40 V < VGN < 2.40 V
2.40 V < VGN < 2.65 V
0.4 V < VGN < 2.4 V
VREF = 2.500 V, VOCM = 2.500 V
VREF = 2.500 V, VOCM = 2.500 V
−1.2
−1.0
−3.5
−30
Rev. F | Page 3 of 24
AD605A
Typ
Max
Min
AD605B
Typ
Max
Unit
175 ± 40
3.0
2.5 ± 2.5
1.8
2.7
8.4
12
−20
175 ± 40
3.0
2.5 ± 2.5
1.8
2.7
8.4
12
−20
Ω
pF
V
nV/√Hz
pA/√Hz
dB
dB
dB
40
170
2.5 ± 1.5
2
±40
40
170
2.5 ± 1.5
2
±40
MHz
V/μs
V
Ω
mA
−64
−68
−51
−53
−64
−68
−51
−53
dBc
dBc
dBc
dBc
−72
−60
15
−1
−72
−60
15
−1
dBc
dBc
dBm
dBm
−70
−70
dB
±2.0
45
±2.0
45
ns
kΩ
+1.0
±0.3
−1.25
±0.25
±20
30
+3.0
+1.0
+1.2
–1.2
–1.0
–3.5
+30
57
–30
+0.75
±0.2
−1.25
±0.25
±20
30
+3.0
+1.0
+1.2
+30
50
dB
dB
dB
dB/V
mV
mV
AD605
Parameter
GAIN CONTROL INTERFACE
Gain Scaling Factor
Gain Range
Input Voltage (VGN) Range
Input Bias Current
Input Resistance
Response Time
POWER SUPPLY
Supply Voltage
Power Dissipation
VREF Input Resistance
Quiescent Supply Current
Power-Down
Power-Up Response Time
Power-Down Response Time
Conditions
Min
VREF = 2.5 V, 0.4 V < VGN < 2.4 V
VREF = 1.67 V
FBK short to OUT
FBK open
20 dB/V, VREF = 2.5 V
19
4.5
48 dB gain change
VPOS
VPOS, VGN < 50 mV
48 dB gain, VOUT = 2 V p-p
Rev. F | Page 4 of 24
AD605A
Typ
Max
Min
20
30
−14 to +34
0 to 48
0.1 to 2.9
−0.4
2
0.2
21
19
5.0
90
10
18
1.9
0.6
0.4
5.5
4.5
23
3.0
AD605B
Typ
Max
Unit
20
30
−14 to +34
0 to 48
0.1 to 2.9
−0.4
2
0.2
21
dB/V
dB/V
dB
dB
V
μA
MΩ
μs
5.0
90
10
18
1.9
0.6
0.4
5.5
V
mW
kΩ
mA
mA
μs
μs
23
3.0
AD605
ABSOLUTE MAXIMUM RATINGS
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Table 2.
Parameter
Supply Voltage +VS
Pin 12, Pin 13 (with Pin 4, Pin 5 = 0 V)
Input Voltage Pin 1 to Pin 3, Pin 6 to Pin 9, Pin 16
Internal Power Dissipation
16-Lead PDIP
16-Lead SOIC_N
Operating Temperature Range
Storage Temperature Range
Lead Temperature, Soldering 60 sec
Thermal Resistance θJA
16-Lead PDIP
16-Lead SOIC_N
Rating
6.5 V
VPOS, 0 V
1.4 W
1.2 W
−40°C to +85°C
−65°C to +150°C
300°C
ESD CAUTION
85°C/W
100°C/W
Rev. F | Page 5 of 24
AD605
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
VGN1 1
16 VREF
–IN1 2
15 OUT1
+IN1 3
GND1 4
14 FBK1
AD605
+IN2 6
11 FBK2
–IN2 7
10 OUT2
VGN2 8
9 VOCM
00541-002
13 VPOS
TOP VIEW
GND2 5 (Not to Scale) 12 VPOS
Figure 2. Pin Configuration
Table 3. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Mnemonic
VGN1
−IN1
+IN1
GND1
GND2
+IN2
−IN2
VGN2
VOCM
OUT2
FBK2
VPOS
VPOS
FBK1
OUT1
VREF
Description
CH1 Gain Control Input and Power-Down Pin. If grounded, device is off; otherwise, positive voltage increases gain.
CH1 Negative Input.
CH1 Positive Input.
Ground.
Ground.
CH2 Positive Input.
CH2 Negative Input.
CH2 Gain Control Input and Power-Down Pin. If grounded, device is off; otherwise, positive voltage increases gain.
Input to This Pin Defines Common-Mode Voltage for OUT1 and OUT2.
CH2 Output.
Feedback Pin That Selects Gain Range of CH2.
Positive Supply.
Positive Supply.
Feedback Pin That Selects Gain Range of CH1.
CH1 Output.
Input to This Pin Sets Gain Scaling for Both Channels: 2.5 V = 20 dB/V and 1.67 V = 30 dB/V.
Rev. F | Page 6 of 24
AD605
TYPICAL PERFORMANCE CHARACTERISTICS (PER CHANNEL)
VREF = 2.5 V (20 dB/V scaling), f = 1 MHz, RL = 500 Ω, CL = 5 pF, TA = 25°C, VSS = 5 V.
40.0
40
–40°C, +25°C, +85°C
GAIN SCALING (dBV)
35.0
20
GAIN (dB)
THEORETICAL
37.5
30
10
0
32.5 ACTUAL
30.0
27.5
25.0
–10
0.1
0.5
0.9
1.3
1.7
VGN (V)
2.1
2.5
20.0
1.25
2.9
00541-006
00541-003
–20
22.5
1.50
1.75
2.00
2.25
2.50
VREF (V)
Figure 3. Gain vs. VGN
Figure 6. Gain Scaling vs. VREF
50
3.0
2.5
40
2.0
1.5
FBK (OPEN)
GAIN ERROR (dB)
20
FBK (SHORT)
10
0
1.0
0
–0.5
+25°C
+85°C
–1.0
–1.5
00541-004
–20
0.1
0.5
0.9
1.3
1.7
VGN (V)
2.1
2.5
00541-007
–2.0
–10
–2.5
–3.0
0.2
2.9
0.7
1.2
1.7
2.2
2.7
VGN (V)
Figure 4. Gain vs. VGN for Different Gain Ranges
Figure 7. Gain Error vs. VGN at Three Temperatures
40
2.0
1.5
30
30dB/V
(VREF = 1.67V)
20
ACTUAL
1.0
GAIN ERROR (dB)
ACTUAL
20dB/V
(VREF = 2.50V)
10
0
f = 1MHz
0.5
0
f = 5MHz
–0.5
f = 10MHz
–1.0
–10
–20
–1.5
00541-005
GAIN (dB)
–40°C
0.5
0.1
0.5
0.9
1.3
1.7
VGN (V)
2.1
2.5
–2.0
2.9
00541-008
GAIN (dB)
30
0.2
0.7
1.2
1.7
2.2
VGN (V)
Figure 5. Gain vs. VGN for Different Gain Scalings
Figure 8. Gain Error vs. VGN at Three Frequencies
Rev. F | Page 7 of 24
2.7
AD605
2.0
60
VGN = 2.9V (FBK = OPEN)
1.5
40
VGN = 2.9V (FBK = SHORT)
VGN = 1.5V (FBK = OPEN)
20
20dB/V
VREF = 2.50V
0.5
GAIN (dB)
GAIN ERROR
1.0
0
30dB/V
VREF = 1.67V
–0.5
VGN = 1.5V (FBK = SHORT)
VGN = 0.1V (FBK = OPEN)
0
VGN = 0.1V (FBK = SHORT)
–20
–1.0
VGN = 0.0V
00541-009
–2.0
0.2
0.7
1.2
1.7
2.2
00541-013
–40
–1.5
–60
100k
2.7
1M
10M
FREQUENCY (Hz)
VGN (V)
Figure 12. AC Response for Three Values of VGN
Figure 9. Gain Error vs. VGN for Two Gain Scale Values
2.515
14
2.510
12
2.505
VOS (V)
16
10
2.495
6
2.490
4
2.485
2
2.480
–0.8
–0.6
–0.4
–0.2
0
0.2
DELTA GAIN (dB)
0.4
0.6
2.475
0.8
+25°C
+85°C
0
0.5
1.0
1.5
2.0
2.5
3.0
VGN (V)
Figure 10. Gain Match, VGN1 = VGN2 = 1.0 V
Figure 13. Output Offset vs. VGN at Three Temperatures
20
18
–40°C
2.500
8
0
VOCM = 2.50V
2.520
00541-010
PERCENTAGE
18
2.525
N = 50
ΔG(dB) = G(CH1) – G(CH2)
00541-014
20
100M
130
N = 50
ΔG(dB) = G(CH1) – G(CH2)
+85°C
125
16
120
NOISE (nV/ Hz)
+25°C
12
10
8
115
110
–40°C
105
6
100
4
–0.8
–0.6
–0.4
–0.2
0
0.2
DELTA GAIN (dB)
0.4
0.6
90
0
0.8
00541-015
2
0
95
00541-011
PERCENTAGE
14
0.5
1.0
1.5
2.0
2.5
3.0
VGN (V)
Figure 14. Output Referred Noise vs. VGN at Three Temperatures
Figure 11. Gain Match, VGN1 = VGN2 = 2.50 V
Rev. F | Page 8 of 24
AD605
1000
100
VGN = 2.9V
1
0.1
0.5
0.9
1.3
1.7
VGN (V)
2.1
2.5
10
1.0
RSOURCE ALONE
00541-019
NOISE (nV/ Hz)
10
00541-016
NOISE (nV/ Hz)
100
0.1
1
2.9
10
100
1k
RSOURCE (Ω)
Figure 18. Input Referred Noise vs. RSOURCE
Figure 15. Input Referred Noise vs. VGN
30
2.00
VGN = 2.9V
VGN = 2.9V
1.95
25
NOISE FIGURE (dB)
NOISE (nV/ Hz)
1.90
1.85
1.80
1.75
20
15
1.70
00541-017
1.60
–40 –30 –20 –10
0
10
20
30
40
50
60
70
80
00541-020
10
1.65
5
1
90
10
100
Figure 19. Noise Figure vs. RSOURCE
Figure 16. Input Referred Noise vs. Temperature
60
1.90
VGN = 2.9V
RS = 50Ω
50
NOISE FIGURE (dB)
1.80
1.75
1.70
40
30
20
1M
FREQUENCY (Hz)
0
0.1
10M
Figure 17. Input Referred Noise vs. Frequency
00541-021
10
1.65
00541-018
NOISE (nV/ Hz)
1.85
1.60
100k
1k
RSOURCE (Ω)
TEMPERATURE (°C)
0.5
0.9
1.3
1.7
VGN (V)
2.1
Figure 20. Noise Figure vs. VGN
Rev. F | Page 9 of 24
2.5
2.9
AD605
15
–30
VOUT = 1V p-p
VGN = 1.0V
10
–40
INPUT GENERATOR
LIMIT = 21dBm
5
–45
PIN (dBm)
–50
HD3
–55
HD2
10M
FREQUENCY (Hz)
FREQ = 10MHz
FREQ = 1MHz
–15
00541-022
–65
1M
–5
–10
–60
–70
100k
0
–20
0.1
100M
Figure 21. Harmonic Distortion vs. Frequency
0.5
0.9
00541-025
HARMONIC DISTORTION (dBc)
–35
1.3
1.7
VGN (V)
2.1
2.5
2.9
Figure 24. 1 dB Compression vs. VGN
–35
35
–40
30
HD3
(10MHz)
25
HD2
(10MHz)
–55
–60
–75
0.5
HD3
(1MHz)
0.8
1.1
1.4
1.7
VGN (V)
2.0
2.3
2.6
–5
0.6
2.9
1.0
1.4
1.8
VGN (V)
2.2
2.6
3.0
Figure 25. Third-Order Intercept vs. VGN at 1 MHz and 10 MHz
–20
–40
10
0
Figure 22. Harmonic Distortion vs. VGN at 1 MHz and 10 MHz
–30
f = 10MHz
15
5
–65
–70
f = 1MHz
20
00541-026
–50
HD2
(1MHz)
INTERCEPT (dBm)
–45
00541-023
HARMONIC DISTORTION (dBc)
VOUT = 1V p-p
2V
f = 10MHz
VOUT = 1V p-p
VGN = 1.0V
VOUT = 2V p-p
VGN = 1.5V
–400mV/DIV
–60
–70
–80
–90
–110
–120
9.92
9.96
10.00
10.02
FREQUENCY (MHz)
10.04
00541-027
TRIG'D
–100
00541-024
POUT (dBm)
–50
2V
253ns
Figure 23. Intermodulation Distortion
100ns/DIV
Figure 26. Large Signal Pulse Response
Rev. F | Page 10 of 24
1.253µs
AD605
–30
VOUT = 200mV p-p
VGN = 1.5V
VGN1 = 1V
VOUT1 = 1V p-p
40mV (DIV)
CROSSTALK (dB)
–40
VIN2 = GND
–50
VGN2 = 2.9V
–60
–70
TRIG'D
VGN2 = 2.5V
00541-028
–80
–200
253ns
Figure 27. Small Signal Pulse Response
VGN2 = 0.1V
–90
100k
1.253µs
100ns/DIV
VGN2 = 2.0V
00541-031
200
1M
10M
FREQUENCY (Hz)
100M
Figure 30. Crosstalk (CH1 to CH2) vs. Frequency for Four Values of VGN2
0
VIN = 0dBm
500mV
2.9V
–10
100
VGN = 2.9V
90
VGN (V)
CMRR (dB)
–20
VGN = 2.5V
–30
–40
VGN = 2.0V
VGN = 0.1V
10
500mV
200ns
00541-029
0.0V
–60
100k
00541-032
–50
0%
1M
10M
FREQUENCY (Hz)
100M
Figure 31. CMRR vs. Frequency for Four Values of VGN
Figure 28. Power-Up/Power-Down Response
180
VGN = 2.9V
500mV
2.9V
175
100
VGN (V)
INPUT IMPEDANCE (Ω)
90
170
165
160
155
150
10
0%
100ns
00541-030
500mV
Figure 29. Gain Response
140
100k
00541-033
145
0.1V
1M
10M
FREQUENCY (Hz)
Figure 32. Input Impedance vs. Frequency
Rev. F | Page 11 of 24
100M
AD605
25
16
+IS (AD605)
14
GROUP DELAY (ns)
15
10
5
0
10 20 30 40 50
TEMPERATURE (°C)
10
8
VGN = 0.1V
60
70
80
90
VGN = 2.9V
4
100k
1M
10M
FREQUENCY (Hz)
Figure 34. Group Delay vs. Frequency
Figure 33. Supply Current (One Channel) vs. Temperature
Rev. F | Page 12 of 24
00541-035
0
–40 –30 –20 –10
12
6
+IS (VGN = 0)
00541-034
SUPPLY CURRENT (mA)
20
100M
AD605
THEORY OF OPERATION
The AD605 is a dual-channel, low noise VGA. Figure 35 shows
the simplified block diagram of one channel. Each channel consists
of a single-supply X-AMP® (hereafter called DSX, differential
single-supply X-AMP) comprising the following:
• Precision passive attenuator (differential ladder)
• Gain control block
• VOCM buffer with supply splitting resistors R3 and R4
• Active feedback amplifier 1 (AFA) with gain setting resistors
R1 and R2
The linear-in-dB gain response of the AD605 can generally be
described by Equation 1.
G (dB) = (Gain Scaling (dB/V)) × (Gain Control (V)) −
(19 dB − (14 dB) × (FB))
(1)
where:
FB = 0, if FBK to OUT is shorted.
FB = 1, if FBK to OUT is open.
Each channel provides between −14 dB to +34.4 dB through
0 dB to +48.4 dB of gain, depending on the value of the resistance
connected between Pin FBK and Pin OUT. The center 40 dB of
gain is exactly linear-in-dB while the gain error increases at the top
and bottom of the range. The gain is set by the gain control voltage
(VGN). The VREF input establishes the gain scaling. The useful
gain scaling range is between 20 dB/V and 40 dB/V for a VREF
voltage of 2.5 V and 1.25 V, respectively. For example, if FBK to
OUT is shorted and VREF is set to 2.50 V (to establish a gain
scaling of 20 dB/V), the gain equation simplifies to
G (dB) = (20 (dB/V)) × (VGN (V)) – 19 dB
The desired gain can then be achieved by setting the unipolar
gain control (VGN) to a voltage within its nominal operating
range of 0.25 V to 2.65 V (for 20 dB/V gain scaling). The gain is
monotonic for a complete gain control range of 0.1 V to 2.9 V.
Maximum gain can be achieved at a VGN of 2.9 V.
Because the two channels are identical, only Channel 1 is used
to describe their operation. VREF and VOCM are the only inputs
that are shared by the two channels, and because they are normally
ac grounds, crosstalk between the two channels is minimized.
For the highest gain scaling accuracy, VREF should have an
external low impedance voltage source. For low accuracy 20 dB/V
applications, the VREF input can be decoupled with a capacitor
to ground. In this mode, the gain scaling is determined by the
midpoint between +VCC and GND; therefore, care should be
taken to control the supply voltage to 5 V. The input resistance
looking into the VREF pin is 10 kΩ ± 20%.
The AD605 is a single-supply circuit, and the VOCM pin is used
to establish the dc level of the midpoint of this portion of the
circuit. VOCM needs only an external decoupling capacitor to
ground to center the midpoint between the supply voltages (5 V,
GND). However, if the dc level of the output is important to the
user (see the Applications Information section of the AD9050
data sheet for an example), VOCM can be specifically set. The
input resistance looking into the VOCM pin is 45 kΩ ± 20%.
1
To understand the active-feedback amplifier topology, refer to the AD830
data sheet. The AD830 is a practical implementation of the idea.
(2)
VREF
VGN
GAIN
CONTROL
DIFFERENTIAL
ATTENUATOR
EXT
+
G1
+
Ao
–IN
VPOS
R3
200kΩ
VOCM
+
C3
OUT
175Ω
R2
20Ω
G2
+
3.36kΩ
R1
820Ω
R4
200kΩ
EXT
Figure 35. Simplified Block Diagram of a Single Channel of the AD605
Rev. F | Page 13 of 24
FBK
00541-036
C2
DISTRIBUTED g m
175Ω
C1
+IN
AD605
+IN
R
–6.908dB
R
1.5R
–13.82dB
R
1.5R
R
–20.72dB
1.5R
R
–27.63dB
1.5R
R
–34.54dB
1.5R
–41.45dB
R
–48.36dB
1.5R
1.5R
175Ω
1.5R
175Ω
–IN
R
1.5R
R
1.5R
R
1.5R
R
1.5R
R
1.5R
R
1.5R
R
NOTE: R = 96Ω
1.5R = 144Ω
00541-037
MID
Figure 36. R-1.5R Dual Ladder Network
DIFFERENTIAL LADDER (ATTENUATOR)
AC COUPLING
The attenuator before the fixed gain amplifier is realized by a
differential, 7-stage, R-1.5R resistive ladder network with an
untrimmed input resistance of 175 Ω single ended or 350 Ω
differentially. The signal applied at the input of the ladder
network is attenuated by 6.908 dB per tap; therefore, the
attenuation at the first tap is 6.908 dB, at the second, 13.816 dB,
and so on all the way to the last tap where the attenuation is
48.356 dB (see Figure 36). A unique circuit technique is used to
interpolate continuously between the tap points, thereby providing
continuous attenuation from 0 dB to −48.36 dB. One can think
of the ladder network together with the interpolation mechanism
as a voltage-controlled potentiometer.
The DSX is a single-supply circuit; therefore, its inputs need to
be ac-coupled to accommodate ground-based signals. External
Capacitor C1 and Capacitor C2 in Figure 35 level-shift the input
signal from ground to the dc value established by VOCM (nominal
2.5 V). C1 and C2, together with the 175 Ω looking into each of
DSX inputs (+IN and −IN), act as high-pass filters with corner
frequencies depending on the values chosen for C1 and C2. For
example, if C1 and C2 are 0.1 μF, together with the 175 Ω input
resistance of each side of the differential ladder of the DSX, a −3 dB
high-pass corner at 9.1 kHz is formed.
Because the DSX is a single-supply circuit, some means of
biasing its inputs must be provided. Node MID together with
the VOCM buffer performs this function. Without internal
biasing, external biasing is required. If not done carefully, the
biasing network can introduce additional noise and offsets. By
providing internal biasing, the user is relieved of this task and
only needs to ac couple the signal into the DSX. It should be
made clear again that the input to the DSX is still fully differential if
driven differentially, that is, Pin +IN and Pin −IN see the same
signal but with opposite polarity. What changes is the load seen
by the driver; it is 175 Ω when each input is driven single ended,
but 350 Ω when driven differentially. This can be easily explained
when thinking of the ladder network as two 175 Ω resistors
connected back-to-back with the middle node, MID, being
biased by the VOCM buffer. A differential signal applied between
nodes +IN and −IN results in zero current into Node MID, but
a single-ended signal applied to either input +IN or −IN, while the
other input is ac grounded, causes the current delivered by the
source to flow into the VOCM buffer via Node MID.
A feature of the X-AMP architecture is that the output-referred
noise is constant vs. gain over most of the gain range. Referring
to Figure 36, the tap resistance is approximately equal for all
taps within the ladder, excluding the end sections. The resistance
seen looking into each tap is 54.4 Ω, which makes 0.95 nV/√Hz of
Johnson noise spectral density. Because there are two attenuators,
the overall noise contribution of the ladder network is √2 times
0.95 nV/√Hz or 1.34 nV/√Hz, a large fraction of the total DSX
noise. The rest of the DSX circuit components contribute another
1.20 nV/√Hz, which together with the attenuator produces
1.8 nV/√Hz of total DSX input referred noise.
If the DSX output needs to be ground referenced, another ac
coupling capacitor is required for level shifting. This capacitor also
eliminates any dc offsets contributed by the DSX. With a nominal
load of 500 Ω and a 0.1 μF coupling capacitor, this adds a high-pass
filter with −3 dB corner frequency at about 3.2 kHz.
The choice for all three of these coupling capacitors depends on
the application. They should allow the signals of interest to pass
unattenuated, while at the same time, they can be used to limit
the low frequency noise in the system.
GAIN CONTROL INTERFACE
The gain control interface provides an input resistance of
approximately 2 MΩ at Pin VGN1 and gain scaling factors from
20 dB/V to 40 dB/V for VREF input voltages of 2.5 V to 1.25 V,
respectively. The gain varies linearly in decibels for the center
40 dB of gain range, that is, for VGN equal to 0.4 V to 2.4 V for
the 20 dB/V scale and 0.25 V to 1.25 V for the 40 dB/V scale.
Figure 37 shows the ideal gain curves when the FBK-to-OUT
connection is shorted as described by the following equations:
G (20 dB/V) = 20 × VGN − 19, VREF = 2.500 V
(3)
G (30 dB/V) = 30 × VGN − 19, VREF = 1.6666 V
(4)
G (40 dB/V) = 40 × VGN − 19, VREF = 1.250 V
(5)
The equations show that all gain curves intercept at the same
−19 dB point; this intercept is 14 dB higher (−5 dB) if the FBKto-OUT connection is left open. Outside the central linear
range, the gain starts to deviate from the ideal control law but
still provides another 8.4 dB of range. For a given gain scaling,
one can calculate VREF as
Rev. F | Page 14 of 24
VREF =
2.500 V × 20 dB/V
Gain Scale
(6)
AD605
40dB/V
30dB/V
20dB/V
The AFA makes a differential input structure possible because
one of its inputs (G1) is fully differential; this input is made
up of a distributed gm stage. The second input (G2) is used for
feedback. The output of G1 is some function of the voltages
sensed on the attenuator taps that is applied to a high gain
amplifier (A0). Because of negative feedback, the differential
input to the high gain amplifier is zero; this in turn implies that
the differential input voltage to G2 times gm2 (the transconductance
of G2) is equal to the differential input voltage to G1 times gm1
(the transconductance of G1). Therefore, the overall gain
function of the AFA is
35
30
25
20
GAIN (dB)
15
LINEAR-IN-dB RANGE
OF AD605
10
5
0
–5
0.5
1.0
1.5
2.0
2.5
3.0
g
VOUT
R1× R2
= m1 ×
VATTEN g m 2
R2
GAIN CONTROL VOLTAGE
–10
00541-038
–15
–20
Figure 37. Ideal Gain Curves vs. VREF
Usable gain control voltage ranges are 0.1 V to 2.9 V for the
20 dB/V scale and 0.1 V to 1.45 V for the 40 dB/V scale. VGN
voltages of less than 0.1 V are not used for gain control because
below 50 mV the channel is powered down. This can be used to
conserve power and at the same time gate-off the signal. The
supply current for a powered-down channel is 1.9 mA, and the
response time to power the device on or off is less than 1 μs.
FIXED GAIN AMPLIFIER AND INTERPOLATOR
CIRCUITS—APPLYING AN ACTIVE FEEDBACK
AMPLIFIER
A typical X-amp architecture is powered by a dual polarity
power supply. Because the AD605 operates from a single supply, a
supply common equal to half the value of the supply voltage is
required. An active feedback amplifier (AFA) is used to provide
a differential input and to implement the feedback loop. The
AFA in the AD605 is an op amp with two gm stages; one is used
in the feedback path, and the other is used as a highly linear
differential input.
A multisection distributed gm stage senses the voltages on the
ladder network, one stage for each of the ladder nodes. Only a
few of the stages are active at any time and are dependent on the
gain control voltage.
(7)
where:
VOUT is the output voltage.
VATTEN is the effective voltage sensed on the attenuator.
(R1 + R2)/R2 = 42.
gm1/gm2 = 1.25; the overall gain is therefore 52.5 (34.4 dB).
The AFA has additional features that include the following:
inverting the output signal by switching the positive and negative
input to the ladder network; the possibility of using the −IN
input as a second signal input; and independent control of the
DSX common-mode voltage. Under normal operating conditions,
it is best to connect a decoupling capacitor to Pin VOCM, in
which case, the common- mode voltage of the DSX is half of
the supply voltage; this allows for maximum signal swing.
Nevertheless, the common-mode voltage can be shifted up or
down by directly applying a voltage to VOCM. It can also be
used as another signal input, the only limitation being the
rather low slew rate of the VOCM buffer.
If the dc level of the output signal is not critical, another coupling
capacitor is normally used at the output of the DSX; again, this
is done for level shifting and to eliminate any dc offsets contributed
by the DSX (see the AC Coupling section).
The gain range of the DSX is programmable by a resistor connected
between Pin FBK and Pin OUT. The possible ranges are −14 dB to
+34.4 dB when the pins are shorted together or 0 dB to +48.4 dB
when FBK is left open. For the higher gain range, the bandwidth
of the amplifier is reduced by a factor of five to about 8 MHz
because the gain increased by 14 dB. This is the case for any
constant gain bandwidth product amplifier that includes the
active feedback amplifier.
Rev. F | Page 15 of 24
AD605
APPLICATIONS INFORMATION
0.1µF
VIN
0.1µF
1
VGN1
VREF 16
2.500V
2
–IN1
OUT1 15
OUT
3
+IN1
4
GND1
VPOS 13
5
GND2
VPOS 12
AD605
FBK1 14
6
+IN2
FBK2 11
7
–IN2
OUT2 10
8
VGN2
VOCM 9
0.1µF
5V
0.1µF
C1
0.1µF
VIN
C2
0.1µF
C3
0.1µF
C4
0.1µF
1
VGN1
VREF 16
2
–IN1
OUT1 15
3
+IN1
4
GND1
VPOS 13
5
GND2
VPOS 12
AD605
FBK1 14
6
+IN2
FBK2 11
7
–IN2
OUT2 10
8
VGN2
VOCM 9
2.500V
R1
5V
R2
C5
0.1µF
OUT
C6
0.1µF
Figure 39. Doubling the Gain Range with Two Amplifiers
00541-039
VGN
VGN
00541-040
The basic circuit in Figure 38 shows the connections for one
channel of the AD605 with a gain range of −14 dB to +34.4 dB.
The signal is applied at +IN1. The ac coupling capacitors before
Pin −IN1 and Pin +IN1 should be selected according to the
required lower cutoff frequency. In this example, the 0.1 μF
capacitors, together with the 175 Ω of each of the DSX input
pins, provide a −3 dB high-pass corner of about 9.1 kHz. The
upper cutoff frequency is determined by the amplifier and is
40 MHz.
Figure 38. Basic Connections for a Single Channel
As shown in Figure 38, the output is ac-coupled for optimum
performance. In the case of connecting to the 10-bit, 40 MSPS
ADC, AD9050, ac coupling can be eliminated as long as
Pin VOCM is biased by the same 3.3 V common-mode voltage
as the AD9050.
Pin VREF requires a voltage of 1.25 V to 2.5 V, with gain scaling
between 40 dB/V and 20 dB/V, respectively. Voltage VGN controls
the gain; its nominal operating range is from 0.25 V to 2.65 V
for 20 dB/V gain scaling and 0.125 V to 1.325 V for 40 dB/V
scaling. When this pin is taken to ground, the channel powers
down and disables its output.
CONNECTING TWO AMPLIFIERS TO DOUBLE THE
GAIN RANGE
Figure 39 shows the two channels of the AD605 connected in
series to provide a total gain range of 96.8 dB. When R1 and R2
are shorts, the gain range is from −28 dB to +68.8 dB with a
slightly reduced bandwidth of about 30 MHz. The reduction in
bandwidth is due to two identical low-pass circuits being connected
in series; in the case of two identical single-pole, low-pass filters,
the bandwidth is reduced by exactly √2. If R1 and R2 are
replaced by open circuits, that is, Pin FBK1 and Pin FBK2 are left
unconnected, the gain range shifts up by 28 dB to 0 dB to 96.8 dB.
As previously noted, the bandwidth of each individual channel is
reduced by a factor of 5 to about 8 MHz because the gain increased
by 14 dB. In addition, there is still the √2 reduction because the
series connection of the two channels results in a final
bandwidth of the higher gain version of about 6 MHz.
Two other easy combinations are possible to provide a gain
range of −14 dB to +82.8 dB: make R1 a short and R2 an open,
or make R1 an open and R2 a short. The bandwidth for both of
these cases is dominated by the channel that is set to the higher
gain and is about 8 MHz. From a noise standpoint, the second
choice is the best because by increasing the gain of the first
amplifier, the noise of the second amplifier has less of an impact
on the total output noise. One further observation regarding
noise is that by increasing the gain, the output noise increases
proportionally; therefore, there is no increase in signal-to-noise
ratio. It actually stays fixed.
It should be noted that by selecting the appropriate values of R1
and R2, any gain range between −28 dB to +68.8 dB and 0 dB to
+96.8 dB can be achieved with the circuit in Figure 39. When
using any value other than shorts and opens for R1 and R2, the
final value of the gain range depends on the external resistors
matching the on-chip resistors. Because the internal resistors
can vary by as much as ±20%, the actual values for a particular
gain have to be determined empirically. Note that the two channels
within one part match quite well; therefore, R1 tracks R2 in
Figure 39.
C3 is not required because the common-mode voltage at
Pin OUT1 should be identical to the one at Pin +IN2 and
Pin −IN2. However, because only 1 mV of offset at the output
of the first DSX introduces an offset of 53 mV when the second
DSX is set to the maximum gain of the lowest gain range (34.4 dB),
and 263 mV when set to the maximum gain of the highest gain
range (48.4 dB), it is important to include ac coupling to get the
maximum dynamic range at the output of the cascaded amplifiers.
C5 is necessary if the output signal needs to be referenced to any
common-mode level other than half of the supply as is provided
by Pin OUT2.
Rev. F | Page 16 of 24
AD605
4
f = 1MHz
3
2
GAIN ERROR (dB)
Figure 40 shows the gain vs. VGN for the circuit in Figure 39
at 1 MHz and the lowest gain range (−14 dB to +34.4 dB). Note
that the gain scaling is 40 dB/V, double the 20 dB/V of an
individual DSX; this is the result of the parallel connection of
the gain control inputs, VGN1 and VGN2. The gain can also be
sequentially increased by first increasing the gain of Channel 1
and then Channel 2. In this case, VGN1 and VGN2 are driven
from separate voltage sources, for instance two separate DACs.
Figure 41 shows the gain error of Figure 39.
80
THEORETICAL
–2
–4
0.2
ACTUAL
0.7
1.2
1.7
2.2
VGN (V)
40
Figure 41. Gain Error vs. VGN for the Circuit in Figure 39
30
20
10
0
–10
–20
00541-041
GAIN (dB)
–1
–3
60
50
0
00541-042
f = 1MHz
70
1
–30
–40
0.1
0.5
0.9
1.3
1.7
VGN (V)
2.1
2.5
2.9
Figure 40. Gain vs. VGN for the Circuit in Figure 39
Rev. F | Page 17 of 24
2.7
AD605
EVALUATION BOARD
The AD605-EVALZ provides a platform for the circuit designer
to become familiar with the many operating and performance
features of the AD605 variable gain amplifier. It is a factorydesigned, surface-mount assembly fully tested and ready for
service. Figure 42 is a photograph of the AD605-EVALZ. Multiple
inputs, test points, and jumpers provide circuit configurations that
support any of the operating options of the device. Figure 43 is a
schematic of the board.
Power is required from only a single 5 V supply capable of
supplying 55 mA to 60 mA quiescent current.
INPUT CONNECTIONS
The AD605 VGA accepts differential or single-ended input
signals and provides single-ended outputs. The SMA connectors
enable either configuration to be used, as well as the output and
gain control signals. Each of the I/O ports is also available at a
test-loop labeled for easy identification.
The input resistance at each of the four input SMA connectors is
50 Ω, consisting of the 175 Ω, ±40 Ω resistance of the attenuator
ladder network in parallel with the external 69.8 Ω resistors. For
single-ended operation, unused inputs can be left disconnected
or optional jumpers installed. Either VGA input is usable; for
noninverting operation, the INPx is used, and for signal inversion,
the INMx is used.
ADJUSTING GAIN, COMMON-MODE, AND
REFERENCE LEVELS
The gain of each channel is adjusted with trimmers, GN1ADJ and
GN2ADJ. Trimmer VREF ADJ adjusts the gain scaling in dB/V (or
gain slope), and VOCM ADJ adjusts the output common-mode
voltage for both channels. For dynamic gain control, JP1 and
JP4 can be removed and the signal applied at the SMA
connectors, GN1 and GN2.
00541-043
OUTPUT CONNECTIONS
Figure 42. AD605–EVALZ Evaluation Board
SMA connectors, OUT1 and OUT2, are the output connectors.
Series resistors and capacitors are included for termination and
dc blocking purposes. The output of the AD605 has a commonmode value of one-half the supply (unless amended by a voltage
applied to the VCM pin).
Table 4 lists jumpers and their functions, and Figure 44 shows
the evaluation board in a typical test configuration.
Table 4. Table of Jumpers
Jumper
JP1
JP2
JP3
JP4
JP5
JP6
JP7
JP8
Function
Connects trimmer GN1ADJ to pin VGN1. This jumper can be removed for an ac signal at VGN1.
Grounds the IN1 pin via C2.
Grounds the IN2 pin via C5.
Connects trimmer GN2ADJ to Pin VGN2. This jumper can be removed for an ac signal at VGN2.
Connects trimmer VOCMADJ to the VOCM pin. This jumper can be removed for the half supply default VOCM.
Shifts the gain of Channel 2 up or down by 14 dB.
Shifts the gain of Channel 1 up or down by 14 dB.
Connects trimmer VREFADJ to the VREF pin to change the gain slope.
Rev. F | Page 18 of 24
Default Configuration
Installed
User supplied
User supplied
Installed
Installed
Installed
Installed
Installed
AD605
+5V
CH1_GN
R1
DNI
JP1
C1
1nF
VGA1_NEG
J2
INM1
R4
69.8Ω
JP2
VGA1_POS
J3
INP1
AD605
C2
0.1µF
1
2
C3
0.1µF
3
R3
69.8Ω
4
VGA2_POS
J4
INP2
R6
69.8Ω
VGA2_NEG
J5
INM2
5
C4
0.1µF
6
7
C5
0.1µF
8
R5
JP3
69.8Ω
CH2_GN
VGN1
VREF
–IN1
OUT1
+IN1
FBK1
GND1
VPOS
GND2
VPOS
+IN2
FBK2
–IN2
OUT2
VGN2
JP4
J6
GN2
C6
1nF
R7
DNI
VOCM
VREF
ADJ
R14
10kΩ
+5V
R2
10kΩ
GN1
ADJ
C14
0.1µF
JP8
VREF
16
C13
OUT1 R13
0.1µF
49.9Ω
15
14
R12
DNI
JP7
+5V
C12 C11
13 0.1µF 0.1µF
+ C8
10µF
10V
12
J8
OUT1
C7
0.1µF
+5V
GND1
11
10
C10
0.1µF
VOCM
9
+5V
R8
10kΩ
GN2
ADJ
R11 R10
DNI 49.9Ω
JP6
J7
OUT2
OUT2
+5V VOCM
ADJ
JP5
C9
0.1µF
R9
10kΩ
GND2 GND3 GND4
00541-044
J1
GN1
NOTES
1. PARTS IN GRAY ARE NOT INSTALLED.
Figure 43. Schematic Diagram of the AD605-EVALZ Evaluation Board
OSCILLOSCOPE
POWER SUPPLY
+5 V
GND
5V
FUNCTION GENERATOR
VGA OUTPUT
(TO SCOPE)
00541-045
SINGLE-ENDED
INPUT
Figure 44. Typical Test Configuration of the AD605-EVALZ
Rev. F | Page 19 of 24
00541-046
00541-049
AD605
Figure 48. AD605-EVALZ Internal Ground Plane
00541-047
00541-050
Figure 45. AD605-EVALZ Assembly
Figure 49. AD605-EVALZ Internal Power Plane
00541-051
00541-048
Figure 46. AD605-EVALZ Primary Side Copper
Figure 47. AD605-EVALZ Secondary Side Copper
Figure 50. AD605-EVALZ Primary Side Silkscreen
Rev. F | Page 20 of 24
AD605
OUTLINE DIMENSIONS
0.800 (20.32)
0.790 (20.07)
0.780 (19.81)
16
9
1
8
0.280 (7.11)
0.250 (6.35)
0.240 (6.10)
0.325 (8.26)
0.310 (7.87)
0.300 (7.62)
0.100 (2.54)
BSC
0.060 (1.52)
MAX
0.210 (5.33)
MAX
0.195 (4.95)
0.130 (3.30)
0.115 (2.92)
0.015
(0.38)
MIN
0.150 (3.81)
0.130 (3.30)
0.115 (2.92)
0.015 (0.38)
GAUGE
PLANE
SEATING
PLANE
0.022 (0.56)
0.018 (0.46)
0.014 (0.36)
0.430 (10.92)
MAX
0.005 (0.13)
MIN
0.014 (0.36)
0.010 (0.25)
0.008 (0.20)
0.070 (1.78)
0.060 (1.52)
0.045 (1.14)
073106-B
COMPLIANT TO JEDEC STANDARDS MS-001-AB
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
CORNER LEADS MAY BE CONFIGURED AS WHOLE OR HALF LEADS.
Figure 51. 16-Lead Plastic Dual In-Line Package [PDIP]
(N-16)
Dimensions shown in inches and (millimeters)
10.00 (0.3937)
9.80 (0.3858)
4.00 (0.1575)
3.80 (0.1496)
9
16
1
8
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0039)
COPLANARITY
0.10
0.51 (0.0201)
0.31 (0.0122)
6.20 (0.2441)
5.80 (0.2283)
1.75 (0.0689)
1.35 (0.0531)
SEATING
PLANE
0.50 (0.0197)
0.25 (0.0098)
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
Figure 52. 16-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-16)
Dimensions shown in millimeters and (inches)
Rev. F | Page 21 of 24
060606-A
COMPLIANT TO JEDEC STANDARDS MS-012-AC
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
AD605
ORDERING GUIDE
Model
AD605AN
AD605ANZ 1
AD605AR
AD605AR-REEL
AD605AR-REEL7
AD605ARZ1
AD605ARZ-RL1
AD605ARZ-R71
AD605BN
AD605BR
AD605BR-REEL
AD605BR-REEL7
AD605BRZ1
AD605BRZ-RL1
AD605BRZ-R71
AD605-EVALZ1
AD605ACHIPS
1
Temperature Range
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
Package Description
16-Lead PDIP
16-Lead PDIP
16-Lead SOIC_N
16-Lead SOIC_N, 13" Tape and Reel
16-Lead SOIC_N, 7" Tape and Reel
16-Lead SOIC_N
16-Lead SOIC_N, 13" Tape and Reel
16-Lead SOIC_N, 7" Tape and Reel
16-Lead PDIP
16-Lead SOIC_N
16-Lead SOIC_N, 13" Tape and Reel
16-Lead SOIC_N, 7" Tape and Reel
16-Lead SOIC_N
16-Lead SOIC_N, 13" Tape and Reel
16-Lead SOIC_N, 7" Tape and Reel
Evaluation Board
DIE
Z = RoHS Compliant Part.
Rev. F | Page 22 of 24
Package Option
N-16
N-16
R-16
R-16
R-16
R-16
R-16
R-16
N-16
R-16
R-16
R-16
R-16
R-16
R-16
AD605
NOTES
Rev. F | Page 23 of 24
AD605
NOTES
©1996–2008 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D00541-0-6/08(F)
Rev. F | Page 24 of 24