datasheet for AD8648WARUZ by Analog Devices Inc.
24 MHz Rail-to-Rail Amplifiers
with Shutdown Option
AD8646/AD8647/AD8648
PIN CONFIGURATIONS
OUTA 1
–INA 2
AD8646
8
V+
7
OUTB
TOP VIEW
6 –INB
(Not to Scale)
V– 4
5 +INB
+INA 3
06527-001
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: 11 V/μs
Short-circuit output current: 120 mA
Qualified for automotive applications
No phase reversal
Low input bias current: 1 pA
Low supply current per amplifier: 2 mA maximum
Unity gain stable
Figure 1. 8-Lead SOIC and MSOP
OUTA 1
10 V+
–INA 2
AD8647
9
OUTB
+INA 3
TOP VIEW
(Not to Scale)
8
–INB
7
+INB
6
SDB
V– 4
SDA 5
06527-002
FEATURES
Figure 2. 10-Lead MSOP
Battery-powered instruments
Multipole filters
ADC front ends
Sensors
Barcode scanners
ASIC input or output amplifiers
Audio amplifiers
Photodiode amplifiers
Datapath/mux/switch control
OUTA 1
14
OUTD
–INA 2
13
–IND
AD8648
12
+IND
TOP VIEW
(Not to Scale)
11
V–
+INB 5
10
+INC
–INB 6
9
–INC
OUTB 7
8
OUTC
+INA 3
V+ 4
06527-003
APPLICATIONS
Figure 3. 14-Lead SOIC and TSSOP
GENERAL DESCRIPTION
The AD8646 and the AD8647 are the dual, and the AD8648 is
the quad, rail-to-rail, input and output, single-supply amplifiers
featuring low offset voltage, wide signal bandwidth, low input
voltage, and low current noise. The AD8647 also has a low
power shutdown function.
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. TheAD8646/
AD8647/AD8648 offer high output drive capability, which is
excellent for audio line drivers and other low impedance
applications. The AD8646 and AD8648 are available for
automotive applications (see the Ordering Guide).
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. D
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties 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.
www.analog.com
Tel: 781.329.4700
Fax: 781.461.3113 ©2006–2010 Analog Devices, Inc. All rights reserved.
AD8646/AD8647/AD8648
TABLE OF CONTENTS
Features .............................................................................................. 1 ESD Caution...................................................................................6 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................7 Pin Configurations ........................................................................... 1 Theory of Operation ...................................................................... 15 General Description ......................................................................... 1 Power-Down Operation ............................................................ 15 Revision History ............................................................................... 2 Multiplexing Operation ............................................................. 15 Specifications..................................................................................... 3 Outline Dimensions ....................................................................... 16 Absolute Maximum Ratings............................................................ 6 Ordering Guide .......................................................................... 18 Thermal Resistance ...................................................................... 6 REVISION HISTORY
4/10—Rev. C to Rev. D
Changes to Features Section and General Description Section . 1
Updated Outline Dimensions ....................................................... 16
Changes to Ordering Guide Section ............................................ 18
Revision History: AD8646/AD8647/AD8648
2/09—Rev. B to Rev. C
Change to Supply Current Shutdown Mode (AD8647 Only)
Parameter, Table 1............................................................................. 3
Change to Supply Current Shutdown Mode (AD8647 Only)
Parameter, Table 2............................................................................. 5
Added Figure 50; Renumbered Sequentially .............................. 15
Updated Outline Dimensions ....................................................... 16
Changes to Ordering Guide .......................................................... 18
Revision History: AD8648
10/07—Rev. A to Rev. B
Combined with AD8646 ................................................... Universal
Added AD8647 ................................................................... Universal
Deleted Figure 7 .................................................................................6
Deleted Figure 11...............................................................................7
Deleted Figure 16 and Figure 17 .....................................................8
Deleted Figure 24...............................................................................9
Deleted Figure 27, Figure 28, Figure 31, and Figure 32 ............ 10
6/07—Rev. 0 to Rev. A
Changes to General Description .....................................................1
Updated Outline Dimensions ....................................................... 12
Changes to Ordering Guide .......................................................... 12
10/07—Revision B: Initial Combined Version
1/06—Revision 0: Initial Version
Revision History: AD8646
10/07—Rev. 0 to Rev. B
Combined with AD8648.................................................... Universal
Added AD8647 ................................................................... Universal
Deleted Figure 4 and Figure 7 ......................................................... 7
Deleted Figure 33 ............................................................................ 11
8/07—Revision 0: Initial Version
Rev. D | Page 2 of 20
AD8646/AD8647/AD8648
SPECIFICATIONS
VSY = 5 V, VCM = VSY/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 = 0 V to 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
2.5
6.7
pF
pF
4.99
V
V
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
Input Capacitance
Differential
Common Mode
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
Supply Current Shutdown Mode
(AD8647 Only)
SHUTDOWN INPUTS (AD8647)
Logic High Voltage (Enabled)
Logic Low Voltage (Power-Down)
Logic Input Current (Per Pin)
Output Pin Leakage Current
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Phase Margin
Settling Time
Amplifier Turn-On Time (AD8647)
Amplifier Turn-Off Time (AD8647)
VCM
CMRR
AVO
VCM = 0 V to 5 V
RL = 2 kΩ, VO = 0.5 V to 4.5 V
0
67
104
CDIFF
CCM
VOH
VOL
Isc
ZOUT
PSRR
ISY
ISD
VINH
VINL
IIN
SR
GBP
Øm
ts
ton
toff
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
VSY = 2.7 V to 5.5 V
63
8.4
78
RL = 2 kΩ
To 0.1%
25°C, AV = 1, RL = 1 kΩ (see Figure 44)
25°C, AV = 1, RL = 1 kΩ (see Figure 45)
Rev. D | Page 3 of 20
20
40
145
200
±120
5
−40°C < TA < +125°C
Both amplifiers shut down,
VIN_SDA and VIN_SDB = 0 V
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C (shutdown active)
4.92
80
1.5
2.0
2.5
dB
mA
mA
nA
1
μA
+0.8
1
1
V
V
μA
nA
11
24
74
0.5
1
1
V/μs
MHz
Degrees
μs
μs
μs
10
+2.0
AD8646/AD8647/AD8648
Parameter
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Symbol
Conditions
en p-p
en
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
Channel Separation
CS
Total Harmonic Distortion Plus Noise
THD + N
Rev. D | Page 4 of 20
Min
Typ
Max
Unit
2.3
8
6
−115
−110
μV
nV/√Hz
nV/√Hz
dB
dB
0.010
0.021
%
%
AD8646/AD8647/AD8648
VSY = 2.7 V, VCM = VSY/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 = 0 V to 2.7 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
79
102
mV
mV
μV/°C
pA
pA
pA
pA
pA
pA
V
dB
dB
2.5
7.8
pF
pF
2.68
25
30
V
V
mV
mV
mA
Ω
2.0
2.5
dB
mA
mA
nA
1
μA
+0.8
1
1
V
V
μA
nA
V/μs
MHz
Degrees
μs
μs
μs
μV
nV/√Hz
nV/√Hz
dB
dB
1.8
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
Input Capacitance
Differential
Common Mode
OUTPUT CHARACTERISTICS
Output Voltage High
Output Voltage Low
Output Current
Closed-Loop Output Impedance
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current per Amplifier
Supply Current Shutdown Mode
(AD8647 Only)
SHUTDOWN INPUTS (AD8647)
Logic High Voltage (Enabled)
Logic Low Voltage (Power-Down)
Logic Input Current (Per Pin)
Output Pin Leakage Current
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Phase Margin
Settling Time
Amplifier Turn-On Time (AD8647)
Amplifier Turn-Off Time (AD8647)
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Channel Separation
VCM
CMRR
AVO
VCM = 0 V to 2.7 V
RL = 2 kΩ, VO = 0.5 V to 2.2 V
0
62
95
CDIFF
CCM
VOH
VOL
Isc
ZOUT
PSRR
ISY
ISD
VINH
VINL
IIN
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
VSY = 2.7 V to 5.5 V
63
11
±63
5
−40°C < TA < +125°C
Both amplifiers shut down,
VIN_SDA and VIN_SDB = 0 V
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C
−40°C < TA < +125°C (shutdown active)
80
1.6
10
+2.0
SR
GBP
Øm
ts
ton
toff
RL = 2 kΩ
To 0.1%
25°C, AV = 1, RL = 1 kΩ (see Figure 41)
25°C, AV = 1, RL = 1 kΩ (see Figure 42)
11
24
53
0.3
1.2
1
en p-p
en
0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
f = 10 kHz
f = 100 kHz
2.3
8
6
−115
−110
CS
Rev. D | Page 5 of 20
AD8646/AD8647/AD8648
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 VSY
±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_N
8-Lead MSOP
10-Lead MSOP
14-Lead SOIC_N
14-Lead TSSOP
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. D | Page 6 of 20
θJA
125
210
200
120
180
θJC
43
45
44
36
35
Unit
°C/W
°C/W
°C/W
°C/W
°C/W
AD8646/AD8647/AD8648
TYPICAL PERFORMANCE CHARACTERISTICS
300
200
VSY = 2.7V
VCM = 1.35V
TA = 25°C
2244 AMPLIFIERS
160
NUMBER OF AMPLIFIERS
NUMBER OF AMPLIFIERS
250
VSY = 5V
VCM = 2.5V
TA = 25°C
2244 AMPLIFIERS
180
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
06527-004
–1.5
–0.5
0
0.5
1.0
1.5
2.0
Figure 7. Input Offset Voltage Distribution
35
35
VSY = 2.7V
–40°C < TA < +125°C
VSY = 5V
–40°C < TA < +125°C
30
NUMBER OF AMPLIFIERS
30
25
20
15
10
5
25
20
15
10
5
1
2
3
4
5
6
7
0
TCVOS (µV/°C)
0
1
2
3
4
5
6
7
06527-008
0
06527-005
0
8
TCVOS (µV/°C)
Figure 5. VOS Drift (TCVOS) Distribution
Figure 8. VOS Drift (TCVOS) Distribution
2500
2500
VSY = 2.7V
TA = 25°C
2000
VSY = 5V
TA = 25°C
2000
INPUT OFFSET VOLTAGE (µV)
1500
1000
500
0
–500
–1000
–1500
1500
1000
500
0
–500
–1000
–1500
–2000
–2500
0
0.5
1.0
1.5
2.0
2.5
3.0
INPUT COMMON-MODE VOLTAGE (V)
06527-006
–2000
Figure 6. Input Offset Voltage vs. Input Common-Mode Voltage
–2500
0
1
2
3
4
INPUT COMMON-MODE VOLTAGE (V)
5
Figure 9. Input Offset Voltage vs. Input Common-Mode Voltage
Rev. D | Page 7 of 20
06527-009
NUMBER OF AMPLIFIERS
–1.0
VOS (mV)
Figure 4. Input Offset Voltage Distribution
INPUT OFFSET VOLTAGE (µV)
–1.5
06527-007
20
0
–2.0
AD8646/AD8647/AD8648
10000
VSY = 2.7V
TA = 25°C
1000
OUTPUT SATURATION VOLTAGE (mV)
OUTPUT SATURATION VOLTAGE (mV)
10000
VSY – VOH
100
10
VOL
1
VSY = 5V
TA = 25°C
1000
100
10
VSY – VOH
1
0.1
1
10
100
LOAD CURRENT (mA)
06527-010
0.01
0.1
0.001
1
10
100
1000
Figure 13. Output Saturation Voltage vs. Load Current
25
120
VSY = 5V
20
VSY – VOH
15
10
VOL
5
0
–40
–25
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (°C)
VSY – VOH = 10mA
100
80
VOL = 10mA
60
40
20
VSY – VOH = 1mA
0
–40
VOL = 1mA
–25
–10
5
20
35
50
65
80
95
110
125
TEMPERATURE (°C)
Figure 11. Output Saturation Voltage vs. Temperature
06527-014
OUTPUT SATURATION VOLTAGE (mV)
VSY = 2.7V
IL = 1mA
06527-011
Figure 14. Output Saturation Voltage vs. Temperature
300
300
VSY = 2.7V
TA = 125°C
VSY = 5V
TA = 125°C
250
INPUT BIAS CURRENT (pA)
250
200
150
100
0
0.50
150
100
50
0.75
1.00
1.25
1.50
1.75
COMMON-MODE VOLTAGE (V)
2.00
06527-012
50
200
Figure 12. Input Bias Current vs. Common-Mode Voltage
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
COMMON-MODE VOLTAGE (V)
Figure 15. Input Bias Current vs. Common-Mode Voltage
Rev. D | Page 8 of 20
4.5
06527-015
OUTPUT SATURATION VOLTAGE (mV)
0.1
LOAD CURRENT (mA)
Figure 10. Output Saturation Voltage vs. Load Current
INPUT BIAS CURRENT (pA)
0.01
06527-013
VOL
0.1
0.001
AD8646/AD8647/AD8648
M = 52°
20
135
0
180
–20
225
–40
10k
100k
270
100M
10M
1M
60
FREQUENCY (Hz)
45
PHASE
40
90
20
M
135
= 74°
GAIN
0
180
–20
225
–40
10k
100k
1M
270
100M
10M
FREQUENCY (Hz)
Figure 16. Open-Loop Gain and Phase vs. Frequency
Figure 19. Open-Loop Gain and Phase vs. Frequency
60
60
VSY = 2.7V
TA = 25°C
AV = 100
AV = 10
20
AV = 1
0
–20
AV = 10
20
AV = 1
0
–20
–40
10k
100k
1M
10M
100M
FREQUENCY (Hz)
–60
1k
06527-017
–60
1k
10k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 17. Closed-Loop Gain vs. Frequency
06527-020
–40
VSY = 5V
TA = 25°C
AV = 100
40
CLOSED-LOOP GAIN (dB)
40
CLOSED-LOOP GAIN (dB)
0
OPEN-LOOP PHASE SHIFT (Degrees)
90
40
VSY = 5V
RL = 1kΩ
CL = 10pF
06527-019
45
80
OPEN-LOOP GAIN (dB)
OPEN-LOOP GAIN (dB)
60
0
OPEN-LOOP PHASE SHIFT (Degrees)
VSY = 2.7V
RL = 1kΩ
CL = 10pF
06527-016
80
Figure 20. Closed-Loop Gain vs. Frequency
250
120
VSY = 2.7V
TA = 25°C
VSY = 5V
TA = 25°C
100
200
AV = 1
80
ZOUT (Ω)
150
100
AV = 10
60
AV = 100
AV = 10
40
AV = 100
50
0
1
10
100
1k
10k
FREQUENCY (kHz)
100k
1M
Figure 18. ZOUT vs. Frequency
0
1
10
100
1k
10k
FREQUENCY (kHz)
Figure 21. ZOUT vs. Frequency
Rev. D | Page 9 of 20
100k
1M
06527-021
20
06527-018
ZOUT (Ω)
AV = 1
AD8646/AD8647/AD8648
100
100
VSY = 5V
TA = 25°C
80
80
60
60
CMRR (dB)
40
20
40
20
10k
100k
1M
10M
100M
FREQUENCY (Hz)
0
1k
06527-022
0
1k
10k
Figure 22. CMRR vs. Frequency
100
1M
10M
100M
Figure 25. CMRR vs. Frequency
100
VSY = 2.7V
TA = 25°C
PSRR+
100k
FREQUENCY (Hz)
06527-025
CMRR (dB)
VSY = 2.7V
TA = 25°C
VSY = 5V
TA = 25°C
PSRR+
80
80
PSRR–
PSRR (dB)
40
20
60
40
20
10k
100k
1M
10M
FREQUENCY (Hz)
0
1k
06527-023
0
1k
10k
100k
1M
10M
FREQUENCY (Hz)
06527-026
PSRR (dB)
PSRR–
60
Figure 26. PSRR vs. Frequency
Figure 23. PSRR vs. Frequency
70
60
VSY = ±1.35V
TA = 25°C
60
50
VSY = 5V
RL = 10kΩ
TA = 25°C
50
OVERSHOOT (%)
+OS
40
30
20
40
OS+
30
OS–
20
10
0
1
10
100
CLOAD (pF)
1000
Figure 24. Overshoot vs. Load Capacitance
0
10
100
CLOAD (pF)
Figure 27. Overshoot vs. Load Capacitance
Rev. D | Page 10 of 20
1000
06527-027
10
06527-024
OVERSHOOT (%)
–OS
AD8646/AD8647/AD8648
VSY = 2.7V, VCM = 1.35V, VIN = 100mV p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
(200ns/DIV)
(200ns/DIV)
Figure 28. Small-Signal Transient Response
Figure 31. Small-Signal Transient Response
VSY = 5V, VIN = 4V p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
(200ns/DIV)
Figure 29. Large-Signal Transient Response
Figure 32. Large-Signal Transient Response
0.08
0.08
VSY = ±2.5V
RL = 600Ω
0.07
AV = 1
TA = 25°C
0.06
0.07
0.05
0.05
THD + N (%)
0.06
0.04
0.03
0.04
0.03
0.02
0.01
0.01
100
1k
10k
FREQUENCY (Hz)
100k
06527-030
0.02
0
10
Figure 30. THD + Noise vs. Frequency
VSY = ±2.5V
RL = 600Ω
AV = –10
TA = 25°C
0
10
100
1k
10k
FREQUENCY (Hz)
Figure 33. THD + Noise vs. Frequency
Rev. D | Page 11 of 20
100k
06527-033
(200ns/DIV)
06527-032
06527-029
(2V/DIV)
(2V/DIV)
VSY = 2.7V, VIN = 2V p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
THD + N (%)
06527-031
06527-028
(50mV/DIV)
(50mV/DIV)
VSY = 5V, VCM = 2.5V, VIN = 100mV p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
AD8646/AD8647/AD8648
1
VSY = 2.7V TO 5V
TA = 25°C
0.01
06527037
0.001
TIME (1s/DIV)
VSY = 5V
AV = 1
BW = 30kHz
RL = 100kΩ
f = 1kHz
0.0001
0.001
0.01
0.1
06527-034
THD + N (%)
VOLTAGE (1µV/DIV)
0.1
1
OUTPUT AMPLITUDE (V rms)
Figure 37. THD + Noise vs. Output Amplitude
Figure 34. 0.1 Hz to 10 Hz Voltage Noise
1000
1000
VSY = 5V
10
1
10
100
10k
1k
FREQUENCY (Hz)
100
10
1
0.1
25
80
105
125
Figure 38. Input Bias Current vs. Temperature
5.0
TA = 25°C
VSY = 5V
VIN = 4.9V
AV = 1
RL = 10kΩ
TA = 25°C
4.5
2.0
OUTPUT SWING (V p-p)
4.0
1.5
1.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.0
Figure 36. Supply Current per Amplifier vs. Supply Voltage
0
100
1k
FREQUENCY (kHz)
Figure 39. Maximum Output Swing vs. Frequency
Rev. D | Page 12 of 20
10k
06527-036
0.5
06527-039
SUPPLY CURRENT PER AMPLIFIER (mA)
65
TEMPERATURE (°C)
Figure 35. Voltage Noise Density vs. Frequency
2.5
45
06527-038
INPUT BIAS CURRENT (pA)
100
06527-035
VOLTAGE NOISE DENSITY (nV/√Hz)
VSY = 2.7V TO 5V
TA = 25°C
AD8646/AD8647/AD8648
4.0
0
SUPPLY CURRENT PER AMPLIFIER (mA)
VOUT = VSY/2
3.5
CHANNEL SEPARATION (dB)
–20
3.0
2.5
VSY = 2.7V
2.0
VSY = 5V
1.5
1.0
VSY = 5V
RL = 2kΩ
AV = –100
TA = 25°C
V+
3
VIN
–40
R1
20Ω
CS (dB) = 20 log (VOUT/100 = VIN)
+
2
V–
U1
V+
V–
R3
2kΩ
–
0
V–
U2
5
V–
V+
R2
6 200Ω
7
V+
0
0
0
–60
–80
VIN = 2V p-p
–100
–20
0
20
40
60
80
100
120
TEMPERATURE (°C)
VIN = 0.5V p-p
–120
1k
10k
Figure 40. Supply Current per Amplifier vs. Temperature
Figure 43. Channel Separation
VSY = 5V
RL = 1kΩ
AV = 1
TA = 25°C
SHUTDOWN PIN
VOLTAGE (1V/DIV)
VSY = 2.7V
RL = 1kΩ
AV = 1
TA = 25°C
VOLTAGE (1V/DIV)
100k
FREQUENCY (Hz)
SHUTDOWN PIN
AMPLIFIER OUTPUT
TIME (200ns/DIV)
TIME (200ns/DIV)
Figure 44. Turn-On Time
Figure 41. Turn-On Time
VSY = 5V
RL = 1kΩ
AV = 1
TA = 25°C
VOLTAGE (1V/DIV)
SHUTDOWN PIN
AMPLIFIER OUTPUT
SHUTDOWN PIN
TIME (200ns/DIV)
Figure 45. Turn-Off Time
Figure 42. Turn-Off Time
Rev. D | Page 13 of 20
06527-044
AMPLIFIER OUTPUT
06527-046
VOLTAGE (1V/DIV)
VSY = 2.7V
RL = 1kΩ
AV = 1
TA = 25°C
TIME (200ns/DIV)
06527-043
06527-045
AMPLIFIER OUTPUT
06527-042
0
–40
06527-040
0.5
AD8646/AD8647/AD8648
100
100
VSY = 2.7V
VSY = 5V
10
ISY (nA)
1
0.1
0.1
–25
–10
5
20
35
50
65
TEMPERATURE (°C)
80
95
110
125
06527-048
0.01
–40
1
Figure 46. Supply Current with Op-Amp Shutdown vs. Temperature
0.01
–40
–25
–10
5
20
35
50
65
TEMPERATURE (°C)
80
95
110
125
06527-047
ISY (nA)
10
Figure 47. Supply Current with Op-Amp Shutdown vs. Temperature
Rev. D | Page 14 of 20
AD8646/AD8647/AD8648
THEORY OF OPERATION
POWER-DOWN OPERATION
The shutdown function of the AD8647 is referenced to the
negative supply voltage of the operational amplifier. A logic
level high (> 2.0 V) enables the device, while a logic level low
(< 0.8 V) disables the device and places the output in a high
impedance condition. Several outputs can be wire-OR’ed, thus
eliminating a multiplexer. The logic input is a high impedance
CMOS input. If dual or split supplies are used, the logic signals
must be properly referred to the negative supply voltage.
2V
1V
0V
5V
MULTIPLEXING OPERATION
8
9
7
6
5kHz
5V
70
60
50
40
30
20
VSY = 5V
VSY = 2.7V
0
1
–10
0
5
4
0.1
0.2
0.3
0.4
0.5
0.6
0.7
VIN_SDA AND VIN_SDB (V)
0.8
0.9
1
2
2kHz
06527-049
Figure 50. Supply Current Shutdown Mode, AD8647
Figure 48. AD8647 Output Switching
Rev. D | Page 15 of 20
1.0
06527-051
10
3
13kHz
80
10
1/2
AD8647
2
TIME (200µs/DIV)
Figure 49. Switching Waveforms
SUPPLY CURRENT (µA)
1/2
AD8647
06527-050
0V
Because each op amp has a separate logic input enable pin, the
outputs can be connected together if it can be guaranteed that
only one op amp is active at any time. By connecting the op amps
as shown in Figure 48, a multiplexer can be eliminated. With
the reasonably short turn-on and turn-off times, low frequency
signal paths can be smoothly selected. The turn-off time is
slightly faster than the turn-on time so, even when using
sections from two different packages, the overlap is less than
300 nanoseconds.
AD8646/AD8647/AD8648
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
4.00 (0.1574)
3.80 (0.1497)
5
1
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
6.20 (0.2441)
5.80 (0.2284)
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-AA
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 51. 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
5.15
4.90
4.65
5
4
PIN 1
IDENTIFIER
0.65 BSC
0.95
0.85
0.75
15° MAX
1.10 MAX
0.40
0.25
6°
0°
0.23
0.09
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 52. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
Rev. D | Page 16 of 20
0.80
0.55
0.40
100709-B
0.15
0.05
COPLANARITY
0.10
AD8646/AD8647/AD8648
3.10
3.00
2.90
10
3.10
3.00
2.90
5.15
4.90
4.65
6
1
5
PIN 1
IDENTIFIER
0.50 BSC
0.95
0.85
0.75
15° MAX
1.10 MAX
6°
0°
0.30
0.15
0.23
0.13
0.70
0.55
0.40
COMPLIANT TO JEDEC STANDARDS MO-187-BA
091709-A
0.15
0.05
COPLANARITY
0.10
Figure 53. 10-Lead Mini Small Outline Package [MSOP]
(RM-10)
Dimensions shown in millimeters
5.10
5.00
4.90
14
8
4.50
4.40
4.30
6.40
BSC
1
7
PIN 1
0.65 BSC
1.20
MAX
0.15
0.05
COPLANARITY
0.10
0.30
0.19
0.20
0.09
SEATING
PLANE
8°
0°
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1
Figure 54. 14-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-14)
Dimensions shown in millimeters
Rev. D | Page 17 of 20
0.75
0.60
0.45
061908-A
1.05
1.00
0.80
AD8646/AD8647/AD8648
8.75 (0.3445)
8.55 (0.3366)
8
14
1
7
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)
0.50 (0.0197)
0.25 (0.0098)
1.75 (0.0689)
1.35 (0.0531)
SEATING
PLANE
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-012-AB
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.
060606-A
4.00 (0.1575)
3.80 (0.1496)
Figure 55. 14-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-14)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model1, 2
AD8646ARZ
AD8646ARZ-REEL
AD8646ARZ-REEL7
AD8646ARMZ
AD8646ARMZ-REEL
AD8646WARZ-RL
AD8646WARZ-R7
AD8646WARMZ-RL
AD8646WARMZ-R7
AD8647ARMZ
AD8647ARMZ-REEL
AD8648ARZ
AD8648ARZ-REEL
AD8648ARZ-REEL7
AD8648ARUZ
AD8648ARUZ-REEL
AD8648WARUZ
AD8648WARUZ-RL
1
2
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
Package Description
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead MSOP
8-Lead MSOP
10-Lead MSOP
10-Lead MSOP
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead TSSOP
14-Lead TSSOP
14-Lead TSSOP
14-Lead TSSOP
Z = RoHS Compliant Part
W = Qualified for Automotive Applications.
Rev. D | Page 18 of 20
Package Option
R-8
R-8
R-8
RM-8
RM-8
R-8
R-8
RM-8
RM-8
RM-10
RM-10
R-14
R-14
R-14
RU-14
RU-14
RU-14
RU-14
Branding
A1V
A1V
A1V
A1V
A1W
A1W
AD8646/AD8647/AD8648
NOTES
Rev. D | Page 19 of 20
AD8646/AD8647/AD8648
NOTES
©2006–2010 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D06527-0-4/10(D)
Rev. D | Page 20 of 20
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