AD AD8646ARZ

24 MHz Rail-to-Rail
Dual Amplifier
AD8646
Offset voltage: 2.5 mV maximum
Single-supply operation: 2.7 V to 5.5 V
Low noise: 8 nV/√Hz
Wide bandwidth: 24 MHz
Slew rate: 12 V/μs
Short-circuit output current: 150 mA
No phase reversal
Low input bias current: 1 pA
Low supply current: 2 mA maximum
Unity gain stable
PIN CONFIGURATION
OUTA 1
–INA 2
AD8646
8
V+
7
OUTB
TOP VIEW
6 –INB
(Not to Scale)
V– 4
5 +INB
+INA 3
06527-001
FEATURES
Figure 1.
APPLICATIONS
Battery-powered instruments
Multipole filters
ADC front ends
Sensors
Barcode scanners
ASIC input or output amplifiers
Audio amplifiers
Photodiode amplifiers
Datapath/mux/switch control
GENERAL DESCRIPTION
The AD8646 is a dual, rail-to-rail, input and output, singlesupply amplifier featuring low offset voltage, wide signal
bandwidth, low input voltage, and low current noise.
The combination of 24 MHz bandwidth, low offset, low noise,
and very low input bias current makes these amplifiers useful in
a wide variety of applications. Filters, integrators, photodiode
amplifiers, and high impedance sensors all benefit from the
combination of performance features. AC applications benefit
from the wide bandwidth and low distortion. This amplifier
offers high output drive capability, which is excellent for audio
line drivers and other low impedance applications.
Applications include portable and low powered instrumentation, audio amplification for portable devices, portable phone
headsets, barcode scanners, and multipole filters. The ability to
swing rail to rail at both the input and output enables designers
to buffer CMOS ADCs, DACs, ASICs, and other wide output
swing devices in single-supply systems.
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 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
©2007 Analog Devices, Inc. All rights reserved.
AD8646
TABLE OF CONTENTS
Features .............................................................................................. 1
Absolute Maximum Ratings ............................................................5
Applications....................................................................................... 1
Thermal Resistance .......................................................................5
Pin Configuration............................................................................. 1
ESD Caution...................................................................................5
General Description ......................................................................... 1
Typical Performance Characteristics ..............................................6
Revision History ............................................................................... 2
Outline Dimensions ....................................................................... 12
Specifications..................................................................................... 3
Ordering Guide .......................................................................... 12
REVISION HISTORY
8/07—Revision 0: Initial Version
Rev. 0 | Page 2 of 12
AD8646
SPECIFICATIONS
VDD = 5 V, VCM = VDD/2, TA = +25oC, unless otherwise noted.
Table 1.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
VOS
Offset Voltage Drift
Input Bias Current
ΔVOS/ΔT
IB
VCM = 2.5 V
−40°C < TA < +125°C
−40°C < TA < +125°C
Min
Typ
Max
Unit
0.6
2.5
3.2
7.5
1
50
550
0.5
50
250
5
84
116
mV
mV
μV/°C
pA
pA
pA
pA
pA
pA
V
dB
dB
4.99
V
4.92
V
V
mV
mV
mV
mV
mA
Ω
1.8
0.3
−40°C < TA < +85°C
−40°C < TA < +125°C
Input Offset Current
IOS
0.1
−40°C < TA < +85°C
−40°C < TA < +125°C
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
VCM
CMRR
AVO
VOH
VOL
IOUT
ZOUT
PSRR
ISY
VCM = 0 V to 5 V
RL = 2 kΩ, VO = 0.5 V to 4.5 V
0
67
104
IOUT = 1 mA
−40°C < TA < +125°C
IOUT = 10 mA
−40°C < TA < +125°C
IOUT = 1 mA
−40°C < TA < +125°C
IOUT = 10 mA
−40°C < TA < +125°C
Short circuit
At 1 MHz, AV = 1
4.98
4.90
4.85
4.70
VDD = 2.7 V to 5.0 V
63
8.4
78
±120
5
80
1.5
−40°C < TA < +125°C
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Phase Margin
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
SR
GBP
Øm
en p-p
en
Channel Separation
CS
Total Harmonic Distortion Plus Noise
THD+N
20
40
145
200
1.9
2.25
dB
mA
mA
RL = 2 kΩ
11
27
77
V/μs
MHz
Degrees
0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
f = 10 kHz
f = 100 kHz
V p-p = 0.1 V, RL = 600 Ω, f = 25 kHz,
TA = 25°C
AV = +1
AV = −10
2.3
8
6
−129
−119
μV
nV/√Hz
nV/√Hz
dB
dB
0.010
0.021
%
%
Rev. 0 | Page 3 of 12
AD8646
VDD = 2.7 V, VCM = VDD/2, TA = +25oC, unless otherwise noted.
Table 2.
Parameter
INPUT CHARACTERISTICS
Offset Voltage
Symbol
Conditions
VOS
Offset Voltage Drift
Input Bias Current
ΔVOS/ΔT
IB
VCM = 1.35 V
−40°C < TA < +125°C
−40°C < TA < +125°C
Min
Typ
Max
Unit
0.6
2.5
3.2
7.0
1
50
550
0.5
50
250
2.7
mV
mV
μV/°C
pA
pA
pA
pA
pA
pA
V
dB
dB
1.5
0.2
−40°C < TA < +85°C
−40°C < TA < +125°C
Input Offset Current
IOS
0.1
−40°C < TA < +85°C
−40°C < TA < +125°C
Input Voltage Range
Common-Mode Rejection Ratio
Large Signal Voltage Gain
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
VCM
CMRR
AVO
VOH
VOL
IOUT
ZOUT
PSRR
ISY
VCM = 0 V to 2.7 V
RL = 2 kΩ, VO = 0.5 V to 2.2 V
0
62
95
IOUT = 1 mA
−40°C < TA < +125°C
IOUT = 1 mA
−40°C < TA < +125°C
Short circuit
At 1 MHz, AV = 1
2.65
2.60
VDD = 2.7 V to 5.0 V
63
79
107
2.68
11
±63
5
80
1.6
−40°C < TA < +125°C
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Phase Margin
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Channel Separation
SR
RL = 2 kΩ
RL = 10 kΩ
GBP
Øm
en p-p
en
CS
0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
f = 10 kHz
f = 100 kHz
Rev. 0 | Page 4 of 12
25
30
1.9
2.25
V
V
mV
mV
mA
Ω
dB
mA
mA
11
V/μs
26
53
MHz
Degrees
2.3
8
6
−129
−121
μV
nV/√Hz
nV/√Hz
dB
dB
AD8646
ABSOLUTE MAXIMUM RATINGS
THERMAL RESISTANCE
Table 3.
Parameter
Supply Voltage
Input Voltage
Differential Input Voltage
Output Short Circuit to GND
Storage Temperature Range
Operating Temperature Range
Lead Temperature (Soldering 60 sec)
Junction Temperature
Rating
6V
GND to VDD
±3 V
Indefinite
−65°C to +150°C
−40°C to +125°C
300°C
150°C
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 4. Thermal Resistance
Package Type
8-Lead SOIC
8-Lead MSOP
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.
ESD CAUTION
Rev. 0 | Page 5 of 12
θJA
121
210
θJC
43
45
Unit
°C/W
°C/W
AD8646
TYPICAL PERFORMANCE CHARACTERISTICS
300
VSY = 5V
VCM = 2.5V
TA = 25°C
2244 AMPLIFIERS
180
160
NUMBER OF AMPLIFIERS
250
NUMBER OF AMPLIFIERS
200
VSY = 2.7V
VCM = 1.35V
TA = 25°C
2244 AMPLIFIERS
200
150
100
140
120
100
80
60
40
50
–1.0
–0.5
0
0.5
1.0
1.5
2.0
VOS (mV)
0
–2.0
06527-002
–1.5
35
0
0.5
1.0
1.5
2.0
VSY = 5V
–40°C < TA < +125°C
30
NUMBER OF AMPLIFIERS
25
20
15
10
25
20
15
10
5
5
0
1
2
3
4
5
6
0
06527-003
0
7
TCVOS (µV/°C)
0
3
4
5
6
7
8
Figure 6. VOS Drift (TCVOS) Distribution
1000
VSY = 2.7V
TA = 25°C
600
2
TCVOS (µV/°C)
Figure 3. VOS Drift (TCVOS) Distribution
800
1
06527-006
NUMBER OF AMPLIFIERS
–0.5
Figure 5. Input Offset Voltage Distribution
VSY = 2.7V
–40°C < TA < +125°C
30
–1.0
VOS (mV)
Figure 2. Input Offset Voltage Distribution
35
–1.5
06527-005
20
0
–2.0
VSY = 5V
TA = 25°C
800
600
400
400
VOS (µV)
0
–200
200
0
–200
–400
–400
–600
–600
–800
0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
VCM (V)
Figure 4. Input Offset Voltage vs. Input Common-Mode Voltage
–1000
0
1
2
3
4
5
VCM (V)
Figure 7. Input Offset Voltage vs. Input Common-Mode Voltage
Rev. 0 | Page 6 of 12
06527-007
–800
06527-004
VOS (µV)
200
AD8646
10000
1000
VDD – VOH
VOL
10
1
0.01
0.1
1
10
100
LOAD CURRENT (mA)
100
10
VDD – VOH
1
OUTPUT SATURATION VOLTAGE (mV)
VDD – VOH
15
VOL
5
–25
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (°C)
1000
80
VOL = 10mA
60
40
20
VSY – VOH = 1mA
VOL = 1mA
–25
–10
5
20
35
50
65
80
95
110
125
Figure 12. Output Saturation Voltage vs. Temperature
300
VSY = 5V
TA = 125°C
250
INPUT BIAS CURRENT (pA)
250
200
150
100
50
200
150
100
50
0.75
1.00
1.25
1.50
1.75
COMMON-MODE VOLTAGE (V)
2.00
06527-010
INPUT BIAS CURRENT (pA)
100
TEMPERATURE (°C)
VSY = 2.7V
TA = 125°C
0
0.50
10
VSY – VOH = 10mA
100
Figure 9. Output Saturation Voltage vs. Temperature
300
1
VSY = 5V
0
–40
06527-009
OUTPUT SATURATION VOLTAGE (mV)
120
20
0
–40
0.1
Figure 11. Output Saturation Voltage vs. Load Current
VSY = 2.7V
IL = 1mA
10
0.01
LOAD CURRENT (mA)
Figure 8. Output Saturation Voltage vs. Load Current
25
VOL
0.1
0.001
Figure 10. Input Bias Current vs. Common-Mode Voltage
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
INPUT COMMON-MODE VOLTAGE (V)
Figure 13. Input Bias Current vs. Common-Mode Voltage
Rev. 0 | Page 7 of 12
4.5
06527-013
0.1
0.001
1000
06527-012
100
VSY = 5V
TA = 25°C
06527-011
OUTPUT SATURATION VOLTAGE (mV)
VSY = 2.7V
TA = 25°C
06527-008
OUTPUT SATURATION VOLTAGE (mV)
10000
AD8646
20
45
0
0
180
135
40
90
20
45
0
0
–20
–45
–20
–45
–40
–90
–40
–90
1
10
100
1k
10k
FREQUENCY (kHz)
1
10
AV = 1
0
–20
AV = 10
20
AV = 1
0
–20
–40
10k
100k
1M
10M
100M
FREQUENCY (Hz)
–60
1k
06527-015
–60
1k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 15. Closed-Loop Gain vs. Frequency
250
10k
06527-018
–40
VSY = 5V
TA = 25°C
AV = 100
40
AV = 10
20
10k
60
CLOSED-LOOP GAIN (dB)
CLOSED-LOOP GAIN (dB)
40
1k
Figure 17. Open-Loop Gain and Phase vs. Frequency
VSY = 2.7V
TA = 25°C
AV = 100
100
FREQUENCY (kHz)
Figure 14. Open-Loop Gain and Phase vs. Frequency
60
–135
100k
–60
06527-014
–135
100k
–60
PHASE (Degrees)
90
GAIN (dB)
40
VSY = 5V
RL = 1kΩ
CL = 10pF
TA = 25°C
60
PHASE (Degrees)
GAIN (dB)
60
80
06527-017
180
VSY = 2.7V
RL = 1kΩ
CL = 10pF 135
TA = 25°C
80
Figure 18. Closed-Loop Gain vs. Frequency
120
VSY = 2.7V
TA = 25°C
VSY = 5V
TA = 25°C
100
200
AV = 1
80
ZOUT (Ω)
150
100
AV = 10
AV = 10
60
AV = 100
40
AV = 100
50
0
1
10
100
1k
10k
FREQUENCY (kHz)
100k
1M
Figure 16. ZOUT vs. Frequency
0
1
10
100
1k
10k
FREQUENCY (kHz)
Figure 19. ZOUT vs. Frequency
Rev. 0 | Page 8 of 12
100k
1M
06527-019
20
06527-016
ZOUT (Ω)
AV = 1
AD8646
100
VSY = 2.7V
TA = 25°C
80
80
60
60
CMRR (dB)
40
20
VSY = 5V
TA = 25°C
40
20
10k
100k
1M
10M
100M
FREQUENCY (Hz)
0
1k
06527-020
0
1k
10k
Figure 20. CMRR vs. Frequency
1M
10M
100M
Figure 23. CMRR vs. Frequency
100
100
VSY = 2.7V
90 T = 25°C
A
VSY = 5V
TA = 25°C
–PSRR
80
80
70
+PSRR
60
50
40
PSRR (dB)
PSRR (dB)
100k
FREQUENCY (Hz)
06527-023
CMRR (dB)
100
–PSRR
30
60
+PSRR
40
20
10
20
0
10k
100k
1M
10M
100M
FREQUENCY (Hz)
0
06527-021
–20
1k
1
10
Figure 21. PSRR vs. Frequency
60
100
1k
10k
100k
FREQUENCY (kHz)
06527-024
–10
Figure 24. PSRR vs. Frequency
60
VSY = ±1.35V
TA = 25°C
50
VSY = ±2.5V
TA = 25°C
50
OVERSHOOT (%)
40
+OVERSHOOT
30
20
40
30
+OVERSHOOT
20
–OVERSHOOT
10
0
1
10
100
CLOAD (pF)
1000
Figure 22. Small Signal Overshoot vs. Load Capacitance
0
1
10
100
CLOAD (pF)
Figure 25. Small Signal Overshoot vs. Load Capacitance
Rev. 0 | Page 9 of 12
1000
06527-025
10
06527-022
OVERSHOOT (%)
–OVERSHOOT
AD8646
VSY = 2.7V, VCM = 1.35V, VIN = 100mV p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
06527-029
06527-026
(50mV/DIV)
(50mV/DIV)
VSY = 5V, VCM = 2.5V, VIN = 100mV p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
(200ns/DIV)
(200ns/DIV)
Figure 26. 2.7 V Small Signal Transient Response
Figure 29. 5 V Small Signal Transient Response
VSY = 2.7V, VIN = 2V p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
06527-030
06527-027
(2V/DIV)
(2V/DIV)
VSY = 5V, VIN = 4V p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
(200ns/DIV)
(200ns/DIV)
Figure 27. 2.7 V Large Signal Transient Response
Figure 30. 5 V Large Signal Transient Response
0.08
0.07
0.06
THD + N (%)
0.05
0.04
0.03
0.04
0.03
0.02
0.01
0.01
0
10
100
1k
10k
FREQUENCY (Hz)
100k
VSY = ±2.5V
RL = 600Ω
AV = –10
TA = 25°C
0.05
0.02
06527-028
THD + N (%)
VSY = ±2.5V
RL = 600Ω
0.07
AV = 1
TA = 25°C
0.06
0
10
100
1k
10k
FREQUENCY (Hz)
Figure 31. THD + Noise vs. Frequency
Figure 28. THD + Noise vs. Frequency
Rev. 0 | Page 10 of 12
100k
06527-031
0.08
AD8646
20
18
VDD = 5V
16
INPUT BIAS CURRENT (pA)
VOLTAGE NOISE DENSITY (nV/ Hz)
1000
VSY = 5V
TA = 25°C
14
12
10
8
6
4
100
10
1
1k
10k
100k
FREQUENCY (Hz)
0.1
25
06527-032
0
100
4000
105
125
TA = 25°C
BOTH AMPS
ISY, BOTH AMPLIFIERS (µA)
3500
3.5
3.0
2.5
2.0
1.5
1.0
3000
2500
2000
1500
1000
10k
FREQUENCY (kHz)
0
0
0.5
1.5
2.0
2.5
0
CHANNEL SEPARATION (dB)
–20
06527-034
0.00V
4.0
4.5
5.0
VSY = 5V
RL = 2kΩ
AV = –100
TA = 25°C
–40
–60
–80
VIN = 2V p-p
–100
A CH1
3.5
Figure 36. Supply Current vs. Supply Voltage
2.3µV p-p
M4.00s
3.0
VSY (V)
Figure 33. Maximum Output Swing vs. Frequency
VSY = 2.7V TO 5V
TA = 25°C
1.0
–120
1k
VIN = 0.5V p-p
10k
FREQUENCY (Hz)
Figure 34. 0.1 Hz to 10 Hz Voltage Noise
Figure 37. Channel Separation
Rev. 0 | Page 11 of 12
100k
06527-037
1k
06527-033
0
100
06527-036
500
0.5
INPUT REFERRED NOISE (1µV/DIV)
OUTPUT SWING (V p-p)
4.0
80
Figure 35. Input Bias Current vs. Temperature
VSY = 5V
VIN = 4.9V
AV = 1
RL = 10kΩ
TA = 25°C
4.5
65
TEMPERATURE (°C)
Figure 32. Voltage Noise Density vs. Frequency
5.0
45
06527-035
2
AD8646
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
4.00 (0.1574)
3.80 (0.1497)
5
1
6.20 (0.2441)
5.80 (0.2284)
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
SEATING
PLANE
0.50 (0.0196)
0.25 (0.0099)
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
012407-A
COMPLIANT TO JEDEC STANDARDS MS-012-A A
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.
Figure 38. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
3.20
3.00
2.80
8
3.20
3.00
2.80
1
5
5.15
4.90
4.65
4
PIN 1
0.65 BSC
0.95
0.85
0.75
0.15
0.00
1.10 MAX
0.38
0.22
COPLANARITY
0.10
0.23
0.08
0.80
0.60
0.40
8°
0°
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 39. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD8646ARZ 1
AD8646ARZ-REEL1
AD8646ARZ-REEL71
AD8646ARMZ-R21
AD8646ARMZ-REEL1
1
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
Package Description
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
Z = RoHS Compliant Part.
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D06527-0-8/07(0)
Rev. 0 | Page 12 of 12
Package Option
R-8
R-8
R-8
RM-8
RM-8
Branding
A1V
A1V