AD AD8648ARZ

24 MHz Rail-to-Rail Amplifiers
with Shutdown Option
AD8646/AD8647/AD8648
PIN CONFIGURATIONS
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
No phase reversal
Low input bias current: 1 pA
Low supply current per amplifier: 2 mA maximum
Unity gain stable
OUTA 1
Battery-powered instruments
Multipole filters
ADC front ends
Sensors
Barcode scanners
ASIC input or output amplifiers
Audio amplifiers
Photodiode amplifiers
Datapath/mux/switch control
AD8646
8
V+
7
OUTB
TOP VIEW
6 –INB
(Not to Scale)
V– 4
5 +INB
+INA 3
Figure 1. 8-Lead SOIC and MSOP
–INA 2
+INA 3
V– 4
10 V+
AD8647
9
OUTB
TOP VIEW
(Not to Scale)
8
–INB
7
+INB
6
SDB
SDA 5
06527-002
OUTA 1
Figure 2. 10-Lead MSOP
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
–INA 2
06527-001
FEATURES
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.
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. B
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 ©2006–2007 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
Revision History: AD8646/AD8647/AD8648
10/07—Revision B: Initial Combined Version
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
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
6/07—Rev. 0 to Rev. A
8/07—Revision 0: Initial Version
1/06—Revision 0: Initial Version
Changes to General Description .....................................................1
Updated Outline Dimensions....................................................... 12
Changes to Ordering Guide .......................................................... 12
Revision History: AD8648
10/07—Rev. A to Rev. B
Combined with AD8646....................................................Universal
Added AD8647 ...................................................................Universal
Rev. B | 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 5V
−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)
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. B | Page 3 of 20
20
40
145
200
±120
5
−40°C < TA < +125°C
Shutdown of both amplifiers (AD8647 only)
−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
10
1
+2.0
+0.8
1
1
11
24
74
0.5
1
1
dB
mA
mA
nA
μA
V
V
μA
nA
V/μs
MHz
Degrees
μs
μs
μs
AD8646/AD8647/AD8648
Parameter
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
Symbol
en p-p
en
Channel Separation
CS
Total Harmonic Distortion Plus Noise
THD + N
Conditions
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
Rev. B | 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
V
V
mV
mV
mA
Ω
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)
VCM
CMRR
AVO
0
62
95
CDIFF
CCM
VOH
VOL
IOUT
ZOUT
PSRR
ISY
ISD
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)
SR
GBP
Øm
ts
ton
toff
NOISE PERFORMANCE
Peak-to-Peak Noise
Voltage Noise Density
en p-p
en
Channel Separation
VCM = 0 V to 2.7 V
RL = 2 kΩ, VO = 0.5 V to 2.2 V
VINH
VINL
VIN
CS
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
Shutdown of both amplifiers (AD8647 only)
−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)
25
30
80
1.6
2.0
2.5
10
1
1
V
V
μA
nA
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
V/μs
MHz
Degrees
μs
μs
μs
0.1 Hz to 10 Hz
f = 1 kHz
f = 10 kHz
f = 10 kHz
f = 100 kHz
2.3
8
6
−115
−110
μV
nV/√Hz
nV/√Hz
dB
dB
RL = 2 kΩ
To 0.1%
Rev. B | Page 5 of 20
+2.0
dB
mA
mA
nA
μA
+0.8
1
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
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Rating
6V
GND to VSY
±3 V
Indefinite
−65°C to +150°C
−40°C to +125°C
300°C
150°C
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. B | 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
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
06527-004
–1.5
20
15
10
5
0.5
1.0
1.5
2.0
25
20
15
10
5
1
2
3
4
5
6
7
0
TCVOS (µV/°C)
0
3
4
5
6
7
8
Figure 8. VOS Drift (TCVOS) Distribution
2500
VSY = 2.7V
TA = 25°C
2000
2
TCVOS (µV/°C)
Figure 5. VOS Drift (TCVOS) Distribution
2500
1
06527-008
0
06527-005
0
VSY = 5V
TA = 25°C
2000
INPUT OFFSET VOLTAGE (µV)
1500
1000
500
0
–500
–1000
–1500
1500
1000
500
0
–500
–1000
–1500
0
0.5
1.0
1.5
2.0
2.5
3.0
INPUT COMMON-MODE VOLTAGE (V)
–2500
0
1
2
3
4
INPUT COMMON-MODE VOLTAGE (V)
5
Figure 9. Input Offset Voltage vs. Input Common-Mode Voltage
Figure 6. Input Offset Voltage vs. Input Common-Mode Voltage
Rev. B | Page 7 of 20
06527-009
–2000
–2000
06527-006
INPUT OFFSET VOLTAGE (µV)
0
VSY = 5V
–40°C < TA < +125°C
30
NUMBER OF AMPLIFIERS
NUMBER OF AMPLIFIERS
35
25
–2500
–0.5
Figure 7. Input Offset Voltage Distribution
VSY = 2.7V
–40°C < TA < +125°C
30
–1.0
VOS (mV)
Figure 4. Input Offset Voltage Distribution
35
–1.5
06527-007
20
0
–2.0
AD8646/AD8647/AD8648
10000
100
10
VOL
1
0.01
0.1
1
10
100
LOAD CURRENT (mA)
100
10
VSY – VOH
1
OUTPUT SATURATION VOLTAGE (mV)
VSY – 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 14. 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
06527-012
INPUT BIAS CURRENT (pA)
100
TEMPERATURE (°C)
VSY = 2.7V
TA = 125°C
0
0.50
10
VSY – VOH = 10mA
100
Figure 11. Output Saturation Voltage vs. Temperature
300
1
VSY = 5V
0
–40
06527-011
OUTPUT SATURATION VOLTAGE (mV)
120
20
0
–40
0.1
Figure 13. Output Saturation Voltage vs. Load Current
VSY = 2.7V
IL = 1mA
10
0.01
LOAD CURRENT (mA)
Figure 10. Output Saturation Voltage vs. Load Current
25
VOL
0.1
0.001
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. B | Page 8 of 20
4.5
06527-015
0.1
0.001
1000
06527-013
VSY – VOH
VSY = 5V
TA = 25°C
06527-014
1000
OUTPUT SATURATION VOLTAGE (mV)
VSY = 2.7V
TA = 25°C
06527-010
OUTPUT SATURATION VOLTAGE (mV)
10000
AD8646/AD8647/AD8648
ФM = 52°
20
135
0
180
–20
225
–40
10k
100k
1M
270
100M
10M
60
FREQUENCY (Hz)
90
20
GAIN
180
–20
225
–40
10k
270
100M
10M
FREQUENCY (Hz)
–20
AV = 10
20
AV = 1
0
–20
–40
10k
100k
1M
10M
100M
FREQUENCY (Hz)
–60
1k
06527-017
–60
1k
100k
1M
10M
100M
FREQUENCY (Hz)
Figure 17. Closed-Loop Gain vs. Frequency
250
10k
06527-020
–40
VSY = 5V
TA = 25°C
AV = 100
40
AV = 1
0
1M
60
AV = 10
20
100k
Figure 19. Open-Loop Gain and Phase vs. Frequency
CLOSED-LOOP GAIN (dB)
CLOSED-LOOP GAIN (dB)
40
135
ФM = 74°
0
VSY = 2.7V
TA = 25°C
AV = 100
45
PHASE
40
Figure 16. Open-Loop Gain and Phase vs. Frequency
60
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
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 18. ZOUT vs. Frequency
0
1
10
100
1k
10k
FREQUENCY (kHz)
Figure 21. ZOUT vs. Frequency
Rev. B | Page 9 of 20
100k
1M
06527-021
20
06527-018
ZOUT (Ω)
AV = 1
AD8646/AD8647/AD8648
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
06527-022
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)
100
80
VSY = 5V
TA = 25°C
PSRR+
80
PSRR–
PSRR (dB)
40
20
60
40
20
10k
100k
1M
10M
FREQUENCY (Hz)
0
1k
06527-023
0
1k
10k
Figure 23. PSRR vs. Frequency
60
100k
1M
10M
FREQUENCY (Hz)
06527-026
PSRR (dB)
PSRR–
60
Figure 26. PSRR vs. Frequency
70
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
0
10
100
CLOAD (pF)
Figure 27. Overshoot vs. Load Capacitance
Figure 24. Overshoot vs. Load Capacitance
Rev. B | 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 = 2.7V, VIN = 2V p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
(200ns/DIV)
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
0.06
THD + N (%)
0.05
0.04
0.03
0.05
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. B | Page 11 of 20
100k
06527-033
(200ns/DIV)
06527-032
06527-029
(2V/DIV)
(2V/DIV)
VSY = 5V, VIN = 4V p-p,
TA = 25°C, RL = 10kΩ, CL = 100pF
Figure 29. Large-Signal Transient Response
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
100
10
1
10
100
10k
1k
FREQUENCY (Hz)
VSY = 5V
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
4.0
OUTPUT SWING (V p-p)
2.0
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. B | 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)
VSY = 2.7V TO 5V
TA = 25°C
06527-035
VOLTAGE NOISE DENSITY (nV/√Hz)
1000
AD8646/AD8647/AD8648
0
VOUT = VSY/2
CHANNEL SEPARATION (dB)
–20
3.0
2.5
VSY = 2.7V
2.0
VSY = 5V
1.5
1.0
V+
3
VIN
–40
–20
0
20
40
60
80
100
120
TEMPERATURE (°C)
+
–
0
2
V–
U1
V+
V–
R3
2kΩ
V–
U2
5
V–
V+
R2
6 200Ω
7
V+
0
0
0
–60
–80
VIN = 2V p-p
VIN = 0.5V p-p
–120
1k
10k
100k
FREQUENCY (Hz)
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)
R1
20Ω
CS (dB) = 20 log (VOUT/100 = VIN)
–100
0.5
0
–40
VSY = 5V
RL = 2kΩ
AV = –100
TA = 25°C
SHUTDOWN PIN
AMPLIFIER OUTPUT
TIME (200ns/DIV)
TIME (200ns/DIV)
Figure 41. Turn-On Time
Figure 44. Turn-On Time
VSY = 5V
RL = 1kΩ
AV = 1
TA = 25°C
VOLTAGE (1V/DIV)
SHUTDOWN PIN
SHUTDOWN PIN
TIME (200ns/DIV)
Figure 42. Turn-Off Time
Figure 45. Turn-Off Time
Rev. B | Page 13 of 20
06527-044
AMPLIFIER OUTPUT
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
3.5
06527-040
SUPPLY CURRENT PER AMPLIFIER (mA)
4.0
AD8646/AD8647/AD8648
100
VSY = 2.7V
10
ISY (nA)
ISY (nA)
10
1
0.1
1
0.1
–25
–10
5
20
35
50
65
TEMPERATURE (°C)
80
95
110
125
06527-048
0.01
–40
VSY = 5V
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
100
Figure 47. Supply Current with Op-Amp Shutdown vs. Temperature
Rev. B | Page 14 of 20
AD8646/AD8647/AD8648
THEORY OF OPERATION
POWER-DOWN OPERATION
1/2
AD8647
8
9
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.
7
6
5kHz
5V
1/2
AD8647
2
10
1
3
4
13kHz
5
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.
1
2
2kHz
06527-049
MULTIPLEXING OPERATION
Figure 48. AD8647 Output Switching
2V
1V
0V
5V
TIME (200µs/DIV)
Figure 49. Switching Waveforms
Rev. B | Page 15 of 20
06527-050
0V
AD8646/AD8647/AD8648
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 50. 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
8°
0°
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-187-AA
Figure 51. 8-Lead Mini Small Outline Package [MSOP]
(RM-8)
Dimensions shown in millimeters
Rev. B | Page 16 of 20
0.80
0.60
0.40
AD8646/AD8647/AD8648
3.10
3.00
2.90
6
10
3.10
3.00
2.90
1
5.15
4.90
4.65
5
PIN 1
0.50 BSC
0.95
0.85
0.75
1.10 MAX
0.15
0.05
0.33
0.17
SEATING
PLANE
0.23
0.08
8°
0°
0.80
0.60
0.40
COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-187-BA
Figure 52. 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
1.05
1.00
0.80
0.65
BSC
1.20
MAX
0.15
0.05
0.30
0.19
0.20
0.09
SEATING
COPLANARITY
PLANE
0.10
8°
0°
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1
Figure 53. 14-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-14)
Dimensions shown in millimeters
Rev. B | Page 17 of 20
0.75
0.60
0.45
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 54. 14-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-14)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model
AD8646ARZ 1
AD8646ARZ-REEL1
AD8646ARZ-REEL71
AD8646ARMZ-R21
AD8646ARMZ-REEL1
AD8647ARMZ-R21
AD8647ARMZ-REEL1
AD8648ARZ1
AD8648ARZ-REEL1
AD8648ARZ-REEL71
AD8648ARUZ1
AD8648ARUZ-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
−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
10-Lead MSOP
10-Lead MSOP
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead SOIC_N
14-Lead TSSOP
14-Lead TSSOP
Z = RoHS Compliant Part.
Rev. B | Page 18 of 20
Package Option
R-8
R-8
R-8
RM-8
RM-8
RM-10
RM-10
R-14
R-14
R-14
RU-14
RU-14
Branding
A1V
A1V
A1W
A1W
AD8646/AD8647/AD8648
NOTES
Rev. B | Page 19 of 20
AD8646/AD8647/AD8648
NOTES
©2006–2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D06527-0-10/07(B)
Rev. B | Page 20 of 20