AD8620ARZ-REEL [ADI]
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier; 精密，极低噪声，低输入偏置电流，宽带宽JFET运算放大器
| 型号： | AD8620ARZ-REEL |
| 厂家： | 
ADI |
| 描述： | Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier |
| 文件： | 总24页 (文件大小：1008K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Precision, Very Low Noise,
Low Input Bias Current, Wide
Bandwidth JFET Operational Amplifier
AD8610/AD8620
PIN CONFIGURATIONS
FEATURES
Low noise: 6 nV/√Hz
NULL
–IN
1
2
3
4
8
7
6
5
NC
Low offset voltage: 100 μV maximum
Low input bias current: 10 pA maximum
Fast settling: 600 ns to 0.01%
Low distortion
V+
AD8610
+IN
OUT
NULL
TOP VIEW
(Not to Scale)
V–
NC = NO CONNECT
Unity gain stable
Figure 1. AD8610 8-Lead MSOP and SOIC_N
No phase reversal
Dual-supply operation: ±± V to ±13 V
OUTA
–INA
+INA
V–
1
2
3
4
8
7
6
5
V+
OUTB
–INB
+INB
AD8620
APPLICATIONS
TOP VIEW
(Not to Scale)
Photodiode amplifier
ATE
Instrumentation
Figure 2.AD8620 8-Lead SOIC
Sensors and controls
High performance filters
Fast precision integrators
High performance audio
GENERAL DESCRIPTION
The AD8610/AD8620 are very high precision JFET input ampli-
fiers featuring ultralow offset voltage and drift, very low input
voltage and current noise, very low input bias current, and wide
bandwidth. Unlike many JFET amplifiers, the AD8610/AD8620
input bias current is low over the entire operating temperature
range. The AD8610/AD8620 are stable with capacitive loads of
over 1000 pF in noninverting unity gain; much larger capacitive
loads can be driven easily at higher noise gains. The AD8610/
AD8620 swing to within 1.2 V of the supplies even with a 1 kΩ
load, maximizing dynamic range even with limited supply volt-
ages. Outputs slew at 50 V/μs in either inverting or noninverting
gain configurations, and settle to 0.01% accuracy in less than
600 ns. Combined with high input impedance, great precision
and very high output drive, the AD8610/AD8620 are ideal
amplifiers for driving high performance ADC inputs and
buffering DAC converter outputs.
Applications for the AD8610/AD8620 include electronic instru-
ments; ATE amplification, buffering, and integrator circuits;
CAT/MRI/ultrasound medical instrumentation; instrumentation
quality photodiode amplification; fast precision filters (including
PLL filters); and high quality audio.
The AD8610/AD8620 are fully specified over the extended
industrial (−40°C to +125°C) temperature range. The AD8610
is available in the narrow 8-lead SOIC and the tiny 8-lead MSOP
surface-mount packages. The AD8620 is available in the narrow
8-lead SOIC package. 8-lead MSOP packaged devices are avail-
able only in tape and reel.
Rev. E
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 registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2006 Analog Devices, Inc. All rights reserved.
AD8610/AD8620
TABLE OF CONTENTS
Features .............................................................................................. 1
Absolute Maximum Ratings ............................................................5
Typical Performance Characteristics ..............................................6
Theory of Operation ...................................................................... 13
Functional Description.............................................................. 13
Outline Dimensions....................................................................... 22
Ordering Guide .......................................................................... 22
Applications....................................................................................... 1
Pin Configurations ........................................................................... 1
General Description......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Electrical Specifications............................................................... 4
5/02—Rev. A to Rev. B
REVISION HISTORY
Addition of part number AD8620 ...................................Universal
Addition of 8-Lead SOIC (R-8 Suffix) Drawing............................1
Changes to General Description .....................................................1
Additions to Specifications ..............................................................2
Change to Electrical Specifications.................................................3
Additions to Ordering Guide...........................................................4
Replace TPC 29..................................................................................8
Add Channel Separation Test Circuit Figure.................................9
Add Channel Separation Graph ......................................................9
Changes to Figure 26...................................................................... 15
Addition of High-Speed, Low Noise Differential Driver
11/06—Rev. D to Rev. E
Updated Format..................................................................Universal
Changes to Table 1............................................................................ 3
Changes to Table 2............................................................................ 4
Changes to Outline Dimensions................................................... 21
Changes to Ordering Guide .......................................................... 21
2/04—Rev. C to Rev. D.
Changes to Specifications................................................................ 2
Changes to Ordering Guide ............................................................ 4
Updated Outline Dimensions....................................................... 17
section .............................................................................................. 16
Addition of Figure 30..................................................................... 16
10/02—Rev. B to Rev. C.
Updated Ordering Guide................................................................. 4
Edits to Figure 15............................................................................ 12
Updated Outline Dimensions....................................................... 16
Rev. E | Page 2 of 24
AD8610/AD8620ꢀ
SPECIFICATIONSꢀ
@ VS = ±±5. V, VCM = . V, TA = 2±°C, unless otherwise noted5
Table 1.
Parameter
Symbol
VOS
Conditions
Min
Typ
Max
Unit
INPUT CHARACTERISTICS
Offset Voltage (AD8610B)
45
80
45
80
85
90
150
+2
+130
+1.5
+1
100
200
150
300
250
350
850
+10
+250
+2.5
+10
+75
+150
+3
μV
μV
μV
μV
μV
μV
μV
pA
pA
nA
pA
pA
pA
V
–40°C < TA < +125°C
–40°C < TA < +125°C
Offset Voltage (AD8620B)
VOS
Offset Voltage (AD8610A/AD8620A)
VOS
+25°C < TA < +125°C
–40°C < TA < +125°C
Input Bias Current
IB
–10
–250
–2.5
–10
–75
–150
–2
–40°C < TA < +85°C
–40°C < TA < +125°C
Input Offset Current
IOS
–40°C < TA < +85°C
–40°C < TA < +125°C
+20
+40
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
Offset Voltage Drift (AD8610B)
Offset Voltage Drift (AD8620B)
Offset Voltage Drift (AD8610A/AD8620A)
OUTPUT CHARACTERISTICS
Output Voltage High
CMRR
AVO
ΔVOS/ΔT
ΔVOS/ΔT
ΔVOS/ΔT
VCM = –1.5 V to +2.5 V
RL = 1 kΩ, VO = –3 V to +3 V
–40°C < TA < +125°C
–40°C < TA < +125°C
–40°C < TA < +125°C
90
100
95
dB
180
0.5
0.5
0.8
V/mV
μV/°C
μV/°C
μV/°C
1
1.5
3.5
VOH
VOL
IOUT
RL = 1 kΩ, –40°C < TA < +125°C
RL = 1 kΩ, –40°C < TA < +125°C
3.8
100
40
4
–4
30
V
V
mA
Output Voltage Low
Output Current
–3.8
VOUT
>
2 V
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
PSRR
ISY
VS = 5 V to 13 V
VO = 0 V
–40°C < TA < +125°C
110
2.5
3.0
dB
mA
mA
3.0
3.5
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Settling Time
SR
GBP
tS
RL = 2 kΩ
50
25
350
V/μs
MHz
ns
AV = +1, 4 V step, to 0.01%
NOISE PERFORMANCE
Voltage Noise
en p-p
en
in
0.1 Hz to 10 Hz
f = 1 kHz
f = 1 kHz
1.8
6
5
μV p-p
nV/√Hz
fA/√Hz
Voltage Noise Density
Current Noise Density
Input Capacitance
Differential Mode
Common Mode
CIN
8
15
pF
pF
Channel Separation
f = 10 kHz
f = 300 kHz
CS
137
120
dB
dB
Rev. E | Page 3 of 24
AD8610/AD8620
ELECTRICAL SPECIFICATIONS
@ VS = ±±1 V, VCM = 0 V, TA = 25°C, unless otherwise noted.
Table 2.
Parameter
Symbol
VOS
Conditions
Min
Typ
Max
Unit
INPUT CHARACTERISTICS
Offset Voltage (AD8610B)
45
100
μV
–40°C < TA < +125°C
–40°C < TA < +125°C
80
200
μV
Offset Voltage (AD8620B)
VOS
45
150
μV
80
300
μV
Offset Voltage (AD8610A/AD8620A)
VOS
85
250
μV
+25°C < TA < +125°C
–40°C < TA < +125°C
90
350
μV
150
+3
+130
850
μV
Input Bias Current
IB
–10
+10
+250
+3.5
+10
+75
+150
+10.5
pA
–40°C < TA < +85°C
–40°C < TA < +125°C
–250
–3.5
–10
pA
nA
Input Offset Current
IOS
+1.5
+20
+40
pA
–40°C < TA < +85°C
–40°C < TA < +125°C
–75
pA
–150
–10.5
90
pA
Input Voltage Range
V
Common-Mode Rejection Ratio
Large Signal Voltage Gain
Offset Voltage Drift (AD8610B)
Offset Voltage Drift (AD8620B)
Offset Voltage Drift (AD8610A/AD8620A)
OUTPUT CHARACTERISTICS
Output Voltage High
CMRR
VCM = –10 V to +10 V
RL = 1 kΩ, VO = –10 V to +10 V
–40°C < TA < +125°C
–40°C < TA < +125°C
–40°C < TA < +125°C
110
200
0.5
dB
AVO
100
V/mV
μV/°C
μV/°C
μV/°C
ΔVOS/ΔT
ΔVOS/ΔT
ΔVOS/ΔT
1
0.5
1.5
3.5
0.8
VOH
VOL
IOUT
ISC
RL = 1 kΩ, −40°C < TA < +125°C
RL = 1 kΩ, −40°C < TA < +125°C
VOUT > 10 V
+11.75
+11.84
–11.84
45
V
Output Voltage Low
–11.75
V
Output Current
mA
mA
Short Circuit Current
65
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
PSRR
ISY
VS = 5 V to 13 V
VO = 0 V
100
40
110
3.0
3.5
dB
3.5
4.0
mA
mA
–40°C < TA < +125°C
DYNAMIC PERFORMANCE
Slew Rate
SR
GBP
tS
RL = 2 kΩ
60
V/μs
MHz
ns
Gain Bandwidth Product
Settling Time
25
AV = 1, 10 V step, to 0.01%
600
NOISE PERFORMANCE
Voltage Noise
en p-p
en
0.1 Hz to 10 Hz
f = 1 kHz
1.8
6
μV p-p
nV/√Hz
fA/√Hz
Voltage Noise Density
Current Noise Density
Input Capacitance
Differential Mode
Common Mode
in
f = 1 kHz
5
CIN
8
pF
pF
15
Channel Separation
f = 10 kHz
CS
137
120
dB
dB
f = 300 kHz
Rev. E | Page 4 of 24
AD8610/AD8620ꢀ
ABSOLUTEꢀMAXIMUMꢀRATINGSꢀꢀ
Table 3.
Parameter
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device5 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 implied5 Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability5
Rating
Supply Voltage
Input Voltage
27.3 V
VS− to VS+
Supply Voltage
Indefinite
Differential Input Voltage
Output Short-Circuit Duration to GND
Storage Temperature Range
R, RM Packages
Operating Temperature Range
AD8610/AD8620
Junction Temperature Range
R, RM Packages
Lead Temperature Range (Soldering, 10 sec)
–65°C to +150°C
–40°C to +125°C
Table 4. Thermal Resistance
Package Type
1
θJA
θJC
44
43
Unit
°C/W
°C/W
8-Lead MSOP (RM)
8-Lead SOIC (R)
190
158
–65°C to +150°C
300°C
1 θJA is specified for worst-case conditions; that is, θJA is specified for a device
soldered in circuit board for surface-mount packages.
ESD CAUTION
Rev. E | Page 5 of 24
AD8610/AD8620ꢀꢀ
TYPICALꢀPERFORMANCEꢀCHARACTERISTICSꢀ
14
600
400
200
0
V
= ±13V
S
V
= ±5V
S
12
10
8
6
–200
–400
–600
4
2
0
–250
–150
–50
50
150
250
–40
25
85
125
INPUT OFFSET VOLTAGE (µV)
TEMPERATURE (°C)
Figure 3. Input Offset Voltage at 13 V
Figure 6. Input Offset Voltage vs. Temperature at 5 V (300 Amplifiers)
600
400
200
0
14
V
= ±5V OR ±13V
S
V
= ±13V
S
12
10
8
6
–200
–400
–600
4
2
0
–40
25
85
125
0
0.2
0.6
1.0
T
1.4
1.8
2.2
2.6
TEMPERATURE (°C)
V
(µV/°C)
C
OS
Figure 4. Input Offset Voltage vs. Temperature at 13 V (300 Amplifiers)
Figure 7. Input Offset Voltage Drift
18
3.6
3.4
3.2
3.0
2.8
2.6
2.4
2.2
2.0
V
= ±13V
S
V
= ±5V
S
16
14
12
10
8
6
4
2
0
–250
–150
–50
50
150
250
–10
–5
0
5
10
INPUT OFFSET VOLTAGE (µV)
COMMON-MODE VOLTAGE (V)
Figure 5. Input Offset Voltage at 5 V
Figure 8. Input Bias Current vs. Common-Mode Voltage
Rev. E | Page 6 of 24
AD8610/AD8620ꢀ
3.0
2.5
2.0
1.5
1.0
0.5
0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
V
= ±13V
S
0
1
2
3
4
5
6
7
8
9
10 11 12 13
100
1k
10k
100k
1M
10M
100M
SUPPLY VOLTAGE (±V)
RESISTANCE LOAD (Ω)
Figure 9. Supply Current vs. Supply Voltage
Figure 12. Output Voltage to Supply Rail vs. Load
3.05
2.95
2.85
2.75
2.65
2.55
4.25
4.20
4.15
4.10
4.05
4.00
3.95
V = ±5V
S
V
= ±13V
S
R
= 1kΩ
L
–40
25
85
125
–40
25
85
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 10. Supply Current vs. Temperature at 13 V
Figure 13. Output Voltage High vs. Temperature at 5 V
2.65
–3.95
–4.00
–4.05
–4.10
–4.15
–4.20
–4.25
–4.30
V
= ±5V
S
R
= 1kΩ
L
2.60
2.55
2.50
2.45
2.40
2.35
2.30
–40
25
85
125
–40
25
85
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 11. Supply Current vs. Temperature at 5 V
Figure 14. Output Voltage Low vs. Temperature at 5 V
Rev. E | Page 7 of 24
AD8610/AD8620ꢀꢀ
12.05
60
40
V
R
= ±13V
= 1kΩ
V
R
C
= ±13V
= 2kΩ
= 20pF
S
S
L
L
L
12.00
11.95
11.90
11.85
11.80
G = +100
G = +10
G = +1
20
0
–20
–40
–40
25
85
125
1k
10k
100k
1M
10M
100M
TEMPERATURE (°C)
FREQUENCY (Hz)
Figure 15. Output Voltage High vs. Temperature at 13 V
Figure 18. Closed-Loop Gain vs. Frequency
260
240
220
200
180
160
140
120
100
–11.80
–11.85
–11.90
–11.95
–12.00
–12.05
V
= ±13V
= ±10V
= 1kΩ
S
V
O
R
L
–40
25
85
125
–40
25
85
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 19. AVO vs. Temperature at 13 V
Figure 16. Output Voltage Low vs. Temperature at 13 V
190
180
170
160
150
140
130
120
110
100
120
100
80
270
225
180
135
90
V
R
= ±13V
= 1kΩ
S
V
V
R
= ±5V
= ±3V
= 1kΩ
S
L
O
MARKER AT 27MHz
φ
C
L
= 69.5
= 20pF
M
L
60
40
20
45
0
0
–20
–40
–60
–80
–45
–90
–135
–180
–40
25
85
125
1
10
100
200
TEMPERATURE (°C)
FREQUENCY (MHz)
Figure 20. AVO vs. Temperature at 5 V
Figure 17. Open-Loop Gain and Phase vs. Frequency
Rev. E | Page 8 of 24
AD8610/AD8620ꢀ
160
140
120
100
80
140
120
100
80
V
S
= ±13V
V = ±13V
S
+PSRR
60
60
40
20
40
0
20
–20
–40
0
100
1k
10k
100k
1M
10M
60M
10
100
1k
10k
100k
1M
10M
60M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 21. PSRR vs. Frequency at 13 V
Figure 24. CMRR vs. Frequency
160
140
120
100
80
V
S
= ±5V
V
V
= ±13V
IN
S
= –300mV p-p
= –100
A
R
V
L
= 10kΩ
+PSRR
–PSRR
60
0V
V
V
IN
40
20
CH = 5V/DIV
OUT
2
0
–20
0V
–40
100
1k
10k
100k
1M
10M
60M
FREQUENCY (Hz)
TIME (4µs/DIV)
Figure 22. PSRR vs. Frequency at 5V
Figure 25. Positive Overvoltage Recovery
122
121
120
119
118
117
116
V
V
A
R
C
= ±13V
IN
S
= 300mV p-p
= –100
V
L
L
= 10kΩ
= 0pF
V
IN
0V
0V
V
OUT
CH = 5V/DIV
2
–40
25
85
125
TEMPERATURE (°C)
TIME (4µs/DIV)
Figure 23. PSRR vs. Temperature
Figure 26. Negative Overvoltage Recovery
Rev. E | Page 9 of 24
AD8610/AD8620ꢀꢀ
100
90
80
70
60
50
40
30
20
10
0
V
= ±5V
S
V
V
= ±13V
IN
S
p-p = 1.8µV
GAIN = +1
GAIN = +10
GAIN = +100
1k
10k
100k
1M
10M
100M
TIME (1s/DIV)
FREQUENCY (Hz)
Figure 27. 0.1 Hz to 10 Hz Input Voltage Noise
Figure 30. ZOUT vs. Frequency
3000
2500
2000
1500
1000
500
1000
100
10
V
= ±13V
S
1
0
1
10
100
1k
10k
100k
1M
0
25
85
125
FREQUENCY (Hz)
TEMPERATURE (°C)
Figure 28. Input Voltage Noise Density vs. Frequency
Figure 31. Input Bias Current vs. Temperature
100
40
35
30
25
20
15
10
5
V
= ±13V
S
V
= ±13V
S
L
90
80
70
60
50
40
30
20
10
0
R
= 2kΩ
V
= 100mV p-p
IN
GAIN = +1
+OS
–OS
GAIN = +100
GAIN = +10
0
1k
10k
100k
1M
10M
100M
0
10
100
CAPACITANCE (pF)
1k
10k
FREQUENCY (Hz)
Figure 29. ZOUT vs. Frequency
Figure 32. Small Signal Overshoot vs. Load Capacitance
Rev. E | Page 10 of 24
AD8610/AD8620ꢀ
40
35
30
25
20
15
10
5
V
= ±5V
S
L
R
= 2kΩ
V
= 100mV
IN
+OS
–OS
V
V
A
R
C
= ±13V
p-p = 20V
= +1
S
IN
V
L
L
= 2kΩ
= 20pF
0
0
10
100
CAPACITANCE (pF)
1k
10k
TIME (400ns/DIV)
Figure 33. Small Signal Overshoot vs. Load Capacitance
Figure 36. +SR at G = +1
V
V
A
= ±13V
= ±14V
= +1
S
IN
V
FREQ = 0.5kHz
V
IN
V
OUT
V
V
A
R
C
= ±13V
p-p = 20V
= +1
S
IN
V
L
L
= 2kΩ
= 20pF
TIME (400µs/DIV)
TIME (400ns/DIV)
Figure 34. No Phase Reversal
Figure 37. −SR at G = +1
V
V
A
R
C
= ±13V
p-p = 20V
= +1
V
= ±13V
p-p = 20V
= –1
S
IN
V
L
L
S
V
IN
A
R
C
V
L
L
= 2kΩ
= 2kΩ
= 20pF
= 20pF
TIME (1µs/DIV)
TIME (1µs/DIV)
Figure 35. Large Signal Response at G = +1
Figure 38. Large Signal Response at G =−1
Rev. E | Page 11 of 24
AD8610/AD8620ꢀ
V
V
A
R
= ±13V
p-p = 20V
= –1
S
IN
V
L
= 2kΩ
SR = 50V/µs
= 20pF
C
L
V
V
A
R
= ±13V
p-p = 20V
= –1
S
IN
V
L
= 2kΩ
SR = 55V/µs
= 20pF
C
L
TIME (400ns/DIV)
TIME (400ns/DIV)
Figure 39. +SR at G = −1
Figure 40. −SR at G = −1
Rev. E | Page 12 of 24
AD8610/AD8620
THEORY OF OPERATION
/ 10 × V )
IN
R1
138
136
134
132
130
128
126
124
122
120
CS (dB) = 20 log (V
OUT
20kΩ
+13V
R2
2kΩ
U1
V+
V–
3
2
+
–
V–
V+
6
7
V
IN
20V p-p
5
0
R3
R4
2kΩ
2kΩ
U2
0
–13V
0
0
0
Figure 41. Channel Separation Test Circuit
FUNCTIONAL DESCRIPTION
The AD8610/AD8620 are manufactured on Analog Devices,
Inc.'s XFCB (eXtra fast complementary bipolar) process. XFCB
is fully dielectrically isolated (DI) and used in conjunction with
N-channel JFET technology and thin film resistors (that can be
trimmed) to create the JFET input amplifier. Dielectrically iso-
lated NPN and PNP transistors fabricated on XFCB have an FT
greater than 3 GHz. Low TC thin film resistors enable very accurate
offset voltage and offset voltage tempco trimming. These process
breakthroughs allow Analog Devices’ IC designers to create an
amplifier with faster slew rate and more than 50% higher band-
width at half of the current consumed by its closest competition.
The AD8610/AD8620 are unconditionally stable in all gains,
even with capacitive loads well in excess of 1 nF. The AD8610/
AD8620B grade achieves less than 100 μV of offset and 1 μV/°C
of offset drift, numbers usually associated with very high precision
bipolar input amplifiers. The AD8610 is offered in the tiny 8-lead
MSOP as well as narrow 8-lead SOIC surface-mount packages
and is fully specified with supply voltages from 5 V to 13 V.
The very wide specified temperature range, up to 125°C, guarantees
superior operation in systems with little or no active cooling.
0
50
100
150
200
250
300
350
FREQUENCY (kHz)
Figure 42. AD8620 Channel Separation Graph
8
7
6
5
4
3
2
OPA627
AD8610
–75
–50
–25
0
25
50
75
100
125
TEMPERATURE (°C)
The unique input architecture of the AD8610/AD8620 features
extremely low input bias currents and very low input offset volt-
age. Low power consumption minimizes the die temperature and
maintains the very low input bias current. Unlike many com-
petitive JFET amplifiers, the AD8610/AD8620 input bias currents
are low even at elevated temperatures. Typical bias currents are
less than 200 pA at 85°C. The gate current of a JFET doubles
every 10°C resulting in a similar increase in input bias current
over temperature. Give special care to the PC board layout to
minimize leakage currents between PCB traces. Improper lay-
out and board handling generates a leakage current that exceeds
the bias current of the AD8610/AD8620.
Figure 43. Supply Current vs. Temperature
Power Consumption
A major advantage of the AD8610/AD8620 in new designs is
the power saving capability. Lower power consumption of the
AD8610/AD8620 makes them much more attractive for portable
instrumentation and for high density systems, simplifying ther-
mal management, and reducing power-supply performance
requirements. Compare the power consumption of the AD8610
vs. the OPA627 in Figure 43.
Rev. E | Page 13 of 24
AD8610/AD8620ꢀꢀ
+5V
7
Driving Large Capacitive Loads
3
2
The AD861./AD862. have excellent capacitive load driving
capability and can safely drive up to 1. nF when operating with
±± V supply5 Figure 44 and Figure 4± compare the AD861./
AD862. against the OPA627 in the noninverting gain configu
ration driving a 1. kΩ resistor and 1.,... pF capacitor placed
in parallel on its output, with a square wave input set to a frequency
of 2.. kHz5 The AD861./AD862. have much less ringing than
the OPA627 with heavy capacitive loads5
V
= 50mV
IN
4
2µF
–5V
2kΩ
2kΩ
Figure 46. Capacitive Load Drive Test Circuit
V
= ±5V
S
L
L
R
C
= 10kΩ
= 10,000pF
V
= ±5V
= 10kΩ
= 2µF
S
L
L
R
C
TIME (20µs/DIV)
Figure 47. OPA627 Capacitive Load Drive, AV = +2
TIME (2µs/DIV)
Figure 44. OPA627 Driving CL = 10,000 pF
V
= ±5V
S
L
L
R
C
= 10kΩ
= 10,000pF
V
= ±5V
= 10kΩ
= 2µF
S
L
L
R
C
TIME (20µs/DIV)
Figure 48. AD8610/AD8620 Capacitive Load Drive, AV = +2
TIME (2µs/DIV)
Figure 45. AD8610/AD8620 Driving CL = 10,000 pF
The AD861./AD862. can drive much larger capacitances
without any external compensation5 Although the AD861./
AD862. are stable with very large capacitive loads, remember
that this capacitive loading limits the bandwidth of the amplifier5
Heavy capacitive loads also increase the amount of overshoot
and ringing at the output5 Figure 47 and Figure 48 show the
AD861./AD862. and the OPA627 in a noninverting gain of +2
driving 2 μF of capacitance load5 The ringing on the OPA627 is
much larger in magnitude and continues 1. times longer than
the AD861./AD862.5
Rev. E | Page 14 of 24
AD8610/AD8620ꢀ
Slew Rate (Unity Gain Inverting vs. Noninverting)
V
= ±13V
S
L
R
= 2kΩ
Amplifiers generally have a faster slew rate in an inverting unity
gain configuration due to the absence of the differential input
capacitance5 Figure 49 through Figure ±2 show the performance
of the AD861./AD862. configured in a gain of –1 compared to
the OPA6275 The AD861./AD862. slew rate is more symmetrical,
and both the positive and negative transitions are much cleaner
than in the OPA6275
G = –1
SR = 54V/µs
V
= ±13V
S
L
R
= 2kΩ
G = –1
SR = 54V/µs
TIME (400ns/DIV)
Figure 51. –Slew Rate of AD8610/AD8620 in Unity Gain of –1
V
= ±13V
S
L
R
= 2kΩ
G = –1
SR = 56V/µs
TIME (400ns/DIV)
Figure 49. +Slew Rate of AD8610/AD8620 in Unity Gain of –1
V
= ±13V
S
L
R
= 2kΩ
G = –1
TIME (400ns/DIV)
SR = 42.1V/µs
Figure 52. –Slew Rate of OPA627 in Unity Gain of –1
The AD861./AD862. have a very fast slew rate of 6. V/μs even
when configured in a noninverting gain of +15 This is the toughest
condition to impose on any amplifier since the input common
mode capacitance of the amplifier generally makes its SR appear
worse5 The slew rate of an amplifier varies according to the voltage
difference between its two inputs5 To observe the maximum SR,
a voltage difference of about 2 V between the inputs must be
ensured5 This is required for virtually any JFET op amp so that
one side of the op amp input circuit is completely off, thus maxi
mizing the current available to charge and discharge the internal
compensation capacitance5 Lower differential drive voltages
produce lower slew rate readings5 A JFET input op amp with a
slew rate of 6. V/μs at unity gain with VIN = 1. V might slew at
2. V/μs, if it is operated at a gain of +1.. with VIN = 1.. mV5
TIME (400ns/DIV)
Figure 50. +Slew Rate of OPA627 in Unity Gain of –1
Rev. E | Page 15 of 24
AD8610/AD8620ꢀꢀ
The slew rate of the AD861./AD862. is double that of the
OPA627 when configured in a unity gain of +1 (see Figure ±3
and Figure ±4)5
Input Overvoltage Protection
When the input of an amplifier is driven below VEE or above
VCC by more than one VBE, large currents flow from the sub
strate through the negative supply (V–) or the positive supply
(V+), respectively, to the input pins and can destroy the device5
If the input source can deliver larger currents than the maximum
forward current of the diode (>± mA), a series resistor can be
added to protect the inputs5 With its very low input bias and
offset current, a large series resistor can be placed in front of
the AD861./AD862. inputs to limit current to below damaging
levels5 Series resistance of 1. kΩ generates less than 2± μV of offset5
This 1. kΩ allows input voltages more than ± V beyond either
power supply5 Thermal noise generated by the resistor adds
75± nV/√Hz to the noise of the AD861./AD862.5 For the AD861./
AD862., differential voltages equal to the supply voltage do not
cause any problem (see Figure ±±)5 In this context, please note that
the high breakdown voltage of the input FETs eliminates the need
to include clamp diodes between the inputs of the amplifier, a prac
tice that is mandatory on many precision op amps5 Unfortunately,
clamp diodes greatly interfere with many application circuits
such as precision rectifiers and comparators5 The AD861./
AD862. are free from these limitations5
V
= ±13V
S
L
R
= 2kΩ
G = +1
SR = 85V/µs
TIME (400ns/DIV)
Figure 53. +Slew Rate of AD8610/AD8620 in Unity Gain of +1
V
R
= ±13V
= 2kΩ
S
L
G = +1
+13V
3
7
6
V1
2
4
AD8610
14V
SR = 23V/µs
–13V
0
Figure 56. Unity Gain Follower
No Phase Reversal
Many amplifiers misbehave when one or both of the inputs are
forced beyond the input commonmode voltage range5 Phase
reversal is typified by the transfer function of the amplifier, effect
tively reversing its transfer polarity5 In some cases, this can cause
lockup and even equipment damage in servo systems, and can
cause permanent damage or no recoverable parameter shifts to
the amplifier itself5 Many amplifiers feature compensation cir
cuitry to combat these effects, but some are only effective for
the inverting input5 The AD861./AD862. are designed to prevent
phase reversal when one or both inputs are forced beyond their
input commonmode voltage range5
TIME (400ns/DIV)
Figure 54. +Slew Rate of OPA627 in Unity Gain of +1
The slew rate of an amplifier determines the maximum frequency
at which it can respond to a large signal input5 This frequency
(known as fullpower bandwidth or FPBW) can be calculated
for a given distortion (for example, 1%) from the equation:
SR
FPBW =
(
2π × VPEAK
)
CH = 20.8V p-p
1
V
IN
0V
CH = 19.4V p-p
2
V
0V
OUT
TIME (400ns/DIV)
TIME (400µs/DIV)
Figure 55. AD8610 FPBW
Figure 57. No Phase Reversal
Rev. E | Page 16 of 24
AD8610/AD8620ꢀ
THD Readings vs. Common-Mode Voltage
Settling Time
Total harmonic distortion of the AD8610/AD8620 is well below
0.0006% with any load down to 600 Ω. The AD8610/AD8620
outperform the OPA627 for distortion, especially at frequencies
above 20 kHz.
The AD8610/AD8620 have a very fast settling time, even to a
very tight error band, as can be seen from Figure 60. The AD8610/
AD8620 are configured in an inverting gain of +1 with 2 kΩ input
and feedback resistors. The output is monitored with a 10 X,
10 MΩ, 11.2 pF scope probe.
0.1
1.2k
V
V
= ±13V
S
= 5V rms
IN
BW = 80kHz
1.0k
800
600
400
200
0
0.01
OPA627
0.001
AD8610
0.0001
10
100
1k
10k
80k
0.001
0.01
0.1
1
10
FREQUENCY (Hz)
ERROR BAND (%)
Figure 58. AD8610 vs. OPA627 THD + Noise @ VCM = 0 V
Figure 60. AD8610/AD8620 Settling Time vs. Error Band
0.1
1.2k
V
= ±13V
S
R
= 600Ω
L
1.0k
800
600
400
200
0
2V rms
0.01
4V rms
6V rms
OPA627
0.001
10
100
1k
FREQUENCY (Hz)
10k 20k
0.001
0.01
0.1
ERROR BAND (%)
1
10
Figure 59. THD + Noise vs. Frequency
Figure 61. OPA627 Settling Time vs. Error Band
Noise vs. Common-Mode Voltage
AD8610/AD8620 noise density varies only 10% over the input
range as shown in Table 5.
Table 5. Noise vs. Common-Mode Voltage
VCM at F = 1 kHz (V)
Noise Reading (nV/√Hz)
−10
−5
0
+5
+10
7.21
6.89
6.73
6.41
7.21
Rev. E | Page 17 of 24
AD8610/AD8620ꢀꢀ
10
The AD861./AD862. maintain this fast settling when loaded
with large capacitive loads as shown in Figure 625
3.0
ERROR BAND = ±0.01%
2.5
2.0
1.5
1.0
0.5
0
1
V
V
EE
CC
0.1
0.00001
0.0001
0.001
0.01
0.1
1
LOAD CURRENT (A)
Figure 64. AD8610/AD8620 Dropout from 13 V vs. Load Current
0
500
1000
(pF)
1500
2000
10
C
L
Figure 62. AD8610/AD8620 Settling Time vs. Load Capacitance
3.0
V
CC
2.5
2.0
1.5
1.0
0.5
0
1
V
EE
0.1
0.00001
0.0001
0.001
0.01
0.1
1
LOAD CURRENT (A)
Figure 65. OPA627 Dropout from 15 V vs. Load Current
0
500
1000
(pF)
1500
2000
C
L
Although operating conditions imposed on the AD861./AD862.
(±13 V) are less favorable than the OPA627 (±1± V), it can be
seen that the AD861./AD862. have much better drive capability
(lower headroom to the supply) for a given load current5
Figure 63. OPA627 Settling Time vs. Load Capacitance
Output Current Capability
The AD861./AD862. can drive very heavy loads due to its
high output current5 It is capable of sourcing or sinking 4± mA
at ±1. V output5 The short circuit current is quite high and the
part is capable of sinking about 9± mA and sourcing over 6. mA
while operating with supplies of ±± V5 Figure 64 and Figure 6±
compare the load current vs5 output voltage of AD861./
AD862. and OPA6275
Operating with Supplies Greater than ±±1 V
The AD861./AD862. maximum operating voltage is specified
at ±13 V5 When ±13 V is not readily available, an inexpensive
LDO can provide ±12 V from a nominal ±1± V supply5
Rev. E | Page 18 of 24
AD8610/AD8620
5V
7
Input Offset Voltage Adjustment
Offset of AD8610 is very small and normally does not require
additional offset adjustment. However, the offset adjust pins can
be used as shown in Figure 66 to further reduce the dc offset. By
using resistors in the range of 50 kΩ, offset trim range is ±±.± mV.
100Ω
1
3
2
V
IN
6
AD8610
V
OUT
5
4
+V
S
10kΩ
5pF
+5V
7
2
3
+5V +5V
6
V
AD8610
OUT
12 13
1
V
L
V
DD
5
1kΩ
S1
D1
3
2
R1
4
G = +1
1
16
9
Y0
IN1
ADG452
10kΩ
G
S2 14
–V
S
G = +10
Y1
Y2
Y3
IN2
Figure 66. Offset Voltage Nulling Circuit
1kΩ
100Ω
11Ω
D2 15
S3 11
A0
A1
A
B
Programmable Gain Amplifier (PGA)
G = +100
G = +1000
The combination of low noise, low input bias current, low input
offset voltage, and low temperature drift make the AD8610/
AD8620 a perfect solution for programmable gain amplifiers.
PGAs are often used immediately after sensors to increase the
dynamic range of the measurement circuit. Historically, the large
on resistance of switches (combined with the large IB currents
of amplifiers) created a large dc offset in PGAs. Recent and
improved monolithic switches and amplifiers completely remove
these problems. A PGA discrete circuit is shown in Figure 67.
In Figure 67, when the 10 pA bias current of the AD8610 is
dropped across the (<5 Ω) RON of the switch, it results in a
negligible offset error.
IN3
IN4
D3 10
S4
6
8
D4
7
74HC139
GND
5
V
4
SS
–5V
Figure 67. High Precision PGA
1. Room temperature error calculation due to RON and IB:
ΔVOS = IB × RON = 2 pA × 5 Ω = 10 pV
Total Offset = AD8610 (Offset) + ΔVOS
Total Offset = AD8610 (Offset_Trimmed) + ΔVOS
Total Offset = 5 μV +10 pV ≅ 5 μV
When high precision resistors are used, as in the circuit of
Figure 67, the error introduced by the PGA is within the
½ LSB requirement for a 16-bit system.
2. Full temperature error calculation due to RON and IB:
ΔVOS (@ 85°C) = IB (@ 85°C) × RON (@ 85°C) =
250 pA × 15 Ω = ±.75 nV
±. Temperature coefficient of switch and AD8610/AD8620
combined is essentially the same as the TCVOS of the
AD8610/AD8620:
ΔVOS/ΔT(total) = ΔVOS/ΔT(AD8610/AD8620) +
ΔVOS/ΔT(IB × RON
)
ΔVOS /ΔT(total) = 0.5 μV/°C + 0.06 nV/°C ≅ 0.5 μV /°C
Rev. E | Page 19 of 24
AD8610/AD8620ꢀꢀ
High Speed Instrumentation Amplifier
In active filter applications using operational amplifiers, the dc
accuracy of the amplifier is critical to optimal filter performance5
The offset voltage and bias current of the amplifier contribute to
output error5 Input offset voltage is passed by the filter, and can
be amplified to produce excessive output offset5 For low frequency
applications requiring large value input resistors, bias and offset
currents flowing through these resistors also generate an offset
voltage5
The three op amp instrumentation amplifiers shown in Figure 68
can provide a range of gains from unity up to 1... or higher5 The
instrumentation amplifier configuration features high common
mode rejection, balanced differential inputs, and stable, accurately
defined gain5 Low input bias currents and fast settling are achieved
with the JFET input AD861./AD862.5 Most instrumentation
amplifiers cannot match the high frequency performance of this
circuit5 The circuit bandwidth is 2± MHz at a gain of 1, and close to
± MHz at a gain of 1.5 Settling time for the entire circuit is ±±. ns to
.5.1% for a 1. V step (gain = 1.)5 Note that the resistors around
the input pins need to be small enough in value so that the RC
time constant they form in combination with stray circuit capaci
tance does not reduce circuit bandwidth5
At higher frequencies, the dynamic response of the amplifier
must be carefully considered5 In this case, slew rate, bandwidth,
and openloop gain play a major role in amplifier selection5 The
slew rate must be both fast and symmetrical to minimize
distortion5 The bandwidth of the amplifier, in conjunction with the
gain of the filter, dictates the frequency response of the filter5 The
use of high performance amplifiers such as the AD861./AD862.
minimizes both dc and ac errors in all active filter applications5
V+
8
V
3
IN1
Second-Order Low-Pass Filter
1
1/2 AD8620
U1
4
2
Figure 69 shows the AD861. configured as a secondorder,
Butterworth, lowpass filter5 With the values as shown, the corner
frequency of the filter is 1 MHz5 The wide bandwidth of the
AD861./AD862. allows a corner frequency up to tens of mega
hertz5 The following equations can be used for component
selection:
C5
10pF
V–
V+
7
R1
1kΩ
3
2
V
OUT
R4
2kΩ
R7
2kΩ
C4
15pF
AD8610
6
U2
R1 = R2 =User Selected
Typical Values :1. kΩ−1.. kΩ
R6
2kΩ
RG
4
R8
2kΩ
15414
fCUTOFF (R1)
V–
C1 =
(
2π
)
(
)
R5
2kΩ
.57.7
fCUTOFF (R1)
C2 =
5
V
IN2
C3
15pF
(
2π
)
(
)
7
1/2 AD8620
U1
where C1 and C2 are in farads5
6
R2
1kΩ
+13V
C1
22pF
R2
R1
7
10kΩ 10kΩ
C2
5
3
2
V
10pF
IN
C2
11pF
6
V
OUT
AD8610
Figure 68. High Speed Instrumentation Amplifier
U1
1
High Speed Filters
4
The four most popular configurations are Butterworth, Elliptical,
Bessel (Thompson), and Chebyshev5 Each type has a response
that is optimized for a given characteristic as shown in Table 65
–13V
Figure 69. Second-Order Low-Pass Filter
Table 6. Filter Types
Type
Sensitivity
Overshoot
Phase
Amplitude (Pass Band)
Butterworth
Moderate
Good
Max Flat
Chebyshev
Elliptical
Good
Best
Moderate
Poor
Nonlinear
Linear
Equal Ripple
Equal Ripple
Bessel (Thompson)
Poor
Best
Rev. E | Page 20 of 24
AD8610/AD8620ꢀ
High Speed, Low Noise Differential Driver
V+
The AD862. is a perfect candidate as a low noise differential
driver for many popular ADCs5 There are also other applica
tions (such as balanced lines) that require differential drivers5
The circuit of Figure 7. is a unique line driver widely used in
industrial applications5 With ±13 V supplies, the line driver can
deliver a differential signal of 23 V pp into a 1 kΩ load5 The
high slew rate and wide bandwidth of the AD862. combine to
yield a full power bandwidth of 14± kHz while the low noise
front end produces a referredtoinput noise voltage spectral
density of 6 nV/√Hz5 The design is a balanced transmission system
without transformers, where output commonmode rejection of
noise is of paramount importance5 Like the transformerbased
design, either output can be shorted to ground for unbalanced
line driver applications without changing the circuit gain of 15
This allows the design to be easily set to noninverting, invert
ing, or differential operation5
3
2
1
V+
R4
V
1
O
3
2
1kΩ
R10
R5
1/2 AD8620
U2
R13
6
50Ω
R8
1kΩ
1kΩ
1kΩ
V–
R6
AD8610
R12
1kΩ
R1
1kΩ
V+
10kΩ
0
V–
R7
1kΩ
R9
1kΩ
5
R11
50Ω
R3
1kΩ
7
V
2
O
1/2 AD8620
U3
6
V
2 – V 1 = V
O
O
IN
V–
R2
1kΩ
0
Figure 70. Differential Driver
Rev. E | Page 21 of 24
AD8610/AD8620ꢀꢀ
OUTLINEꢀDIMENSIONSꢀꢀ
5.00 (0.1968)
4.80 (0.1890)
3.20
3.00
2.80
8
1
5
4
6.20 (0.2440)
5.80 (0.2284)
4.00 (0.1574)
3.80 (0.1497)
8
1
5
4
5.15
4.90
4.65
3.20
3.00
2.80
0.50 (0.0196)
0.25 (0.0099)
1.27 (0.0500)
BSC
45°
1.75 (0.0688)
1.35 (0.0532)
PIN 1
0.25 (0.0098)
0.10 (0.0040)
8°
0°
0.65 BSC
0.95
0.85
0.75
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
1.10 MAX
1.27 (0.0500)
0.40 (0.0157)
0.25 (0.0098)
0.17 (0.0067)
SEATING
PLANE
0.80
0.60
0.40
8°
0°
0.15
0.00
0.38
0.22
0.23
0.08
COMPLIANT TO JEDEC STANDARDS MS-012-AA
SEATING
PLANE
COPLANARITY
0.10
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.
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 71. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Figure 72. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model
AD8610AR
Temperature Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package Description
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
Package Option
R-8
R-8
R-8
R-8
Branding
AD8610AR-REEL
AD8610AR-REEL7
AD8610ARZ1
AD8610ARZ-REEL1
AD8610ARZ-REEL71
AD8610ARM-REEL
AD8610ARM-R2
AD8610ARMZ-REEL1
AD8610ARMZ-R21
AD8610BR
AD8610BR-REEL
AD8610BR-REEL7
AD8610BRZ1
AD8610BRZ-REEL1
AD8610BRZ-REEL71
AD8620AR
AD8620AR-REEL
AD8620AR-REEL7
AD8620ARZ1
AD8620ARZ-REEL1
AD8620ARZ-REEL71
AD8620BR
AD8620BR-REEL
AD8620BR-REEL7
AD8620BRZ1
AD8620BRZ-REEL1
AD8620BRZ-REEL71
R-8
R-8
RM-8
RM-8
RM-8
RM-8
R-8
R-8
R-8
R-8
R-8
B0A
B0A
B0A#
B0A#
8-Lead MSOP
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
R-8
1 Z = Pb-free part, # denotes lead-free product can be top or bottom marked.
Rev. E | Page 22 of 24
AD8610/AD8620ꢀ
NOTESꢀꢀ
Rev. E | Page 23 of 24
AD8610/AD8620
NOTES
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C02730-0-11/06(E)
Rev. E | Page 24 of 24
相关型号：
AD8620ARZ-REEL7
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
AD8620BR
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
AD8620BR-REEL
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
AD8620BR-REEL7
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
AD8620BRZ
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
AD8620BRZ-REEL
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
AD8620BRZ-REEL7
Precision, Very Low Noise, Low Input Bias Current, Wide Bandwidth JFET Operational Amplifier
ADI
©2020 ICPDF网 联系我们和版权申明