DATASHEET
ISL28274, ISL28474
FN6345
Rev 3.00
May 14, 2009
Micropower, Single Supply, Rail-to-Rail Input-Output Instrumentation Amplifier and
Precision Operational Amplifier
The ISL28274 is a combination of a micropower
instrumentation amplifier (Amp A) with a low power precision
amplifier (Amp B) in a single package. The ISL28474
consists of two micropower instrumentation amplifiers
(Amp A) and two low power precision amplifiers (Amp B) in a
single package. The amplifiers are optimized for operation at
2.4V to 5V single supplies. Inputs and outputs can operate
rail-to-rail. As with all instrumentation amplifiers, a pair of
inputs provide a high common-mode rejection and are
completely independent from a pair of feedback terminals.
The feedback terminals allow zero input to be translated to
any output offset, including ground. A feedback divider
controls the overall gain of the amplifier. The additional
precision amplifier can be used to generate higher gain, with
smaller feedback resistors or used to generate a reference
voltage.
The instrumentation amp (Amp A) is compensated for a gain
of 100 or more and the precision amp (Amp B) is unity gain
stable. Both amplifiers have PMOS inputs that provide less
than 30pA input bias currents.
The amplifiers can be operated from one lithium cell or two
Ni-Cd batteries. The amplifiers input range goes from below
ground to slightly above positive rail. The output stage
swings completely to ground or positive supply; no pull-up or
pull-down resistors are needed.
Features
• Combination of IN-AMP and OP-AMP in a Single Package
• 120µA Supply Current for ISL28274
• Input Offset Voltage IN-AMP 500µV Max
• Input Offset Voltage OP-AMP 225µV Max
• 30pA Max Input Bias Current
• 100dB CMRR and PSRR
• Single Supply Operation of 2.4V to 5.0V
• Ground Sensing
• Input Voltage Range is Rail-to-Rail and Output Swings
Rail-to-Rail
• Pb-Free available (RoHS Compliant)
Applications
• 4mA to 20mA Loops
• Industrial Process Control
• Medical Instrumentation
Ordering Information
PART NUMBER
(Note)
PART
MARKING
PACKAGE
(Pb-Free)
PKG.
DWG. #
ISL28274FAZ*
28274 FAZ
16 Ld QSOP
MDP0040
ISL28474FAZ*
ISL28474 FAZ
24 Ld QSOP
MDP0040
*Add “-T7” suffix for tape and reel. Please refer to TB347 for details
on reel specifications
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination
finish, which is RoHS compliant and compatible with both SnPb and
Pb-free soldering operations). Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J STD-020.
FN6345 Rev 3.00
May 14, 2009
Page 1 of 18
ISL28274, ISL28474
Pinout
ISL28474
(24 LD QSOP)
TOP VIEW
ISL28274
(16 LD QSOP)
TOP VIEW
16 V+
IA OUT_1 1
24 IA OUT_2
IA OUT 2
15 OUT
IA FB+_1 2
23 IA FB+_2
IA FB+ 3
14 NC
IA FB-_1 3
13 NC
IA IN-_1 4
21 IA IN-_2
IA IN- 5
12 IN-
IA IN+_1 5
20 IA IN+_2
IA IN+ 6
11 IN+
DNC 6
DNC
10 DNC
IA = INSTRUMENTATION
AMPLIFIER
A
+ B
= INSTRUMENTATION
AMPLIFIER
= PRECISION AMPLIFIER
22 IA FB-_2
19 DNC
V+ 7
18 V-
DNC 8
17 DNC
IN+_1 9
16 IN+_2
IN-_1 10
15 IN-_2
NC 11
+ -
9 NC
A
B
- +
+ -
V- 8
- +
7
B
+ -
IA FB- 4
A
A
- +
NC 1
B
14 NC
13 OUT_2
OUT_1 12
+ -
IA = INSTRUMENTATION
AMPLIFIER
A
+ + B
FN6345 Rev 3.00
May 14, 2009
= INSTRUMENTATION
AMPLIFIER
= PRECISION AMPLIFIER
Page 2 of 18
ISL28274, ISL28474
Absolute Maximum Ratings (TA = +25°C)
Thermal Information
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V
Supply Turn-On Voltage Slew Rate . . . . . . . . . . . . . . . . . . . . . 1V/µs
Input Current (IN, FB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
Differential Input Voltage (IN, FB) . . . . . . . . . . . . . . . . . . . . . . . 0.5V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . V- - 0.5V to V+ + 0.5V
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3kV
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300V
Thermal Resistance (Typical Note 1)
JA (°C/W)
16 Ld QSOP Package . . . . . . . . . . . . . . . . . . . . . . .
112
24 Ld QSOP Package . . . . . . . . . . . . . . . . . . . . . . .
88
Output Short-Circuit Duration . . . . . . . . . . . . . . . . . . . . . . .Indefinite
Ambient Operating Temperature Range . . . . . . . . .-40°C to +125°C
Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . +125°C
Pb-Free Reflow Profile. . . . . . . . . . . . . . . . . . . . . . . . .see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.
NOTES:
1. JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
PARAMETER
VOS
TCVOS
IOS
INSTRUMENTATION AMPLIFIER “A” V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise
specified. For ISL28274 ONLY. Boldface limits apply over the operating temperature range, -40°C to +125°C,
temperature data established by characterization.
DESCRIPTION
Input Offset Voltage
MIN
(Note 2)
CONDITIONS
35
400
750
µV
ISL28474
-500
-750
35
500
750
µV
Input Offset Voltage
Temperature Coefficient
Temperature = -40°C to +125°C
3
Input Offset Current
between IN+ and IN-, and
between FB+ and FB-
(see Figure 43 for extended temperature range)
-40°C to +85°C
eN
Input Noise Voltage
VIN
UNIT
-400
-750
Input Bias Current (IN+, IN- (see Figures 35 and 36 for extended temperature range)
FB+, and FB- terminals)
-40°C to +85°C
RIN
MAX
(Note 2)
ISL28274
IB
iN
TYP
µV/°C
-30
-80
±5
30
80
pA
-30
-80
±10
30
80
pA
f = 0.1Hz to 10Hz
6
µVP-P
Input Noise Voltage Density fo = 1kHz
78
nV/Hz
Input Noise Current Density fo = 1kHz
0.19
pA/Hz
1
G
Input Resistance
Input Voltage Range
V+ = 2.4V to 5.0V
0
CMRR
Common Mode Rejection
Ratio
VCM = 0V to 5V
80
75
100
dB
PSRR
Power Supply Rejection
Ratio
V+ = 2.4V to 5V
80
75
100
dB
EG
Gain Error
RL = 100k to 2.5V
-0.2
%
SR
Slew Rate
RL = 1k to VCM
GBWP
Gain Bandwidth Product
FN6345 Rev 3.00
May 14, 2009
VOUT = 10mVP-P; RL = 10k
V+
V
ISL28274
0.40
0.35
0.5
0.65
0.70
V/µs
ISL28474
0.40
0.35
0.5
0.7
0.75
V/µs
6
MHz
Page 3 of 18
ISL28274, ISL28474
Electrical Specifications
PARAMETER
VOS
OPERATIONAL AMPLIFIER “B” V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified.
For ISL28274 ONLY. Boldface limits apply over the operating temperature range, -40°C to +125°C.
DESCRIPTION
MIN
(Note 2)
CONDITIONS
Input Offset Voltage
-225
-450
MAX
(Note 2)
TYP
±20
225
450
UNIT
µV
V OS
-----------------Time
Long Term Input Offset Voltage
Stability
1.2
µV/Mo
V OS
--------------T
Input Offset Drift vs Temperature
2.2
µV/°C
Input Offset Current
(see Figure 45 for extended temperature range)
-40°C to +85°C
-30
-80
±5
30
80
pA
IB
Input Bias Current
(see Figures 39 and 40 for extended temperature range)
-40°C to +85°C
-30
-80
±10
30
80
pA
eN
Input Noise Voltage Peak-to-Peak f = 0.1Hz to 10Hz
5.4
µVP-P
Input Noise Voltage Density
50
nV/Hz
IOS
iN
fO = 1kHz
Input Noise Current Density
fO = 1kHz
CMIR
Input Voltage Range
Guaranteed by CMRR test
0
CMRR
Common-Mode Rejection Ratio
VCM = 0V to 5V
80
75
100
dB
PSRR
Power Supply Rejection Ratio
V+ = 2.4V to 5V
85
80
105
dB
AVOL
Large Signal Voltage Gain
VO = 0.5V to 4.5V, RL = 100k
200
190
300
V/mV
Slew Rate
RL = 1k to VCM
0.12
0.09
±0.14
Gain Bandwidth Product
VOUT = 10mVP-P; RL = 10k
SR
GBW
Electrical Specifications
0.14
0.16
0.21
300
V
V/µs
kHz
COMMON ELECTRICAL SPECIFICATIONS V+ = 5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise
specified. For ISL28274 ONLY. Boldface limits apply over the operating temperature range, -40°C to +125°C.
PARAMETER
DESCRIPTION
VOUT
Maximum Output Voltage Swing
CONDITIONS
MIN
(Note 2)
Output low, RL = 100k to VCM
Output low, RL = 1k to VCM
IS,ON
pA/Hz
5
Supply Current
TYP
MAX
(Note 2)
UNIT
3
6
30
mV
130
175
225
mV
Output high, RL = 100k to VCM
4.990
4.97
4.996
V
Output high, RL = 1k to VCM
4.800
4.750
4.880
V
ISL28274 All channels
120
156
175
µA
ISL28474 All channels
240
315
350
µA
ISC+
Short Circuit Sourcing Capability
RL = 10 to VCM
28
24
31
mA
ISC-
Short Circuit Sinking Capability
RL = 10 to VCM
24
20
26
mA
V+
Minimum Supply Voltage
2.4
V
NOTE:
2. Parts are 100% tested at +25°C. Over temperature limits established by characterization and are not production tested.
FN6345 Rev 3.00
May 14, 2009
Page 4 of 18
ISL28274, ISL28474
Typical Performance Curves
90
70
GAIN = 2,000
GAIN = 1,000
60
GAIN = 500
50
GAIN = 100
40
30
1
10
100k
1
GAIN = 5,000
35
1
GAIN = 100
10
100k
0
1M
AV = 100
RL = 10k
CL = 10pF
RF/RG = 100
RF = 10k
RG = 100
10k
100k
1M
100
1200pF
40
820pF
AV = 100
R = 10k
CL = 10pF
RF/RG = 100
RF = 10k
RG = 100
10
100
56pF
60
AV = 100
40
20
1k
10k
100k
FREQUENCY (Hz)
FIGURE 5. AMPLIFIER “A” (IN-AMP) FREQUENCY
RESPONSE vs CLOAD
FN6345 Rev 3.00
May 14, 2009
80
CMRR (dB)
GAIN (dB)
1k
120
2200pF
45
25
100
FIGURE 4. AMPLIFIER “A” (IN-AMP) FREQUENCY
RESPONSE vs SUPPLY VOLTAGE
50
30
10
FREQUENCY (Hz)
FIGURE 3. AMPLIFIER “A” (IN-AMP) FREQUENCY
RESPONSE vs CLOSED LOOP GAIN
35
1M
20
15
100
1k
10k
FREQUENCY (Hz)
100k
V+ = 2.4V
25
GAIN = 200
10
100
1k
10k
FREQUENCY (Hz)
V+ = 5V
5
30
10
30
GAIN (dB)
GAIN (dB)
GAIN = 100
40
GAIN = 500
40
GAIN = 200
GAIN = 10,000
GAIN = 1,000
50
GAIN = 500
45
GAIN = 2,000
60
GAIN = 1,000
60
FIGURE 2. AMPLIFIER “A” (IN-AMP) FREQUENCY
RESPONSE vs CLOSED LOOP GAIN, VCM = 1/2V+
COMMON-MODE INPUT = VM +10mV
70
GAIN = 2,000
30
1M
FIGURE 1. AMPLIFIER “A” (IN-AMP) FREQUENCY
RESPONSE vs CLOSED LOOP GAIN
80
70
40
100
1k
10k
FREQUENCY (Hz)
90
GAIN = 5,000
50
GAIN = 200
COMMON-MODE INPUT = 1/2V+
GAIN = 10,000
80
GAIN = 5,000
GAIN (dB)
GAIN (dB)
90
COMMON-MODE INPUT = V+
GAIN = 10,000
80
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified.
1M
0
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 6. AMPLIFIER “A” (IN-AMP) CMRR vs FREQUENCY
Page 5 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
700
INPUT VOLTAGE NOISE (nV/Hz)
120
100
PSRR (dB)
80
PSRR+
60
PSRR-
40
AV = 100
20
600
500
400
300
100
0
0
10
100
1k
10k
100k
AV = 100
200
1M
1
10
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
FIGURE 8. AMPLIFIER “A” (IN-AMP) INPUT VOLTAGE NOISE
SPECTRAL DENSITY
FIGURE 7. AMPLIFIER “A” (IN-AMP) PSRR vs FREQUENCY
2.0
VOLTAGE NOISE (2µV/DIV)
CURRENT NOISE (pA/Hz)
1.8
1.6
1.4
1.2
1.0
0.8
AV = 100
0.6
0.4
0.2
0.0
1
10
100
1k
10k
100k
TIME (1s/DIV)
FREQUENCY (Hz)
FIGURE 10. AMPLIFIER “A” (IN-AMP) 0.1Hz TO 10Hz INPUT
VOLTAGE NOISE
FIGURE 9. AMPLIFIER “A” (IN-AMP) INPUT CURRENT
NOISE SPECTRAL DENSITY
45
+1
0
40
-1
GAIN (dB)
-2
V+, V- = ±2.5V
RL = 10k
-3
-4
V+, V- = ±1.2V
RL = 1k
35
V+, V- = ±1.2V
RL = 10k
-5
VOUT = 50mVP-P
-6 AV = 1
CL = 3pF
-7 RF = 0/RG = INF
8
1k
30
GAIN (dB)
V+, V- = ±2.5V
RL = 1k
V+, V- = ±2.5V
25
V+, V- = ±1.2V
20
15
10
5
AV = 100
RL = 10k
CL = 3pF
RF = 100k
RG = 1k
V+, V- = ±1.0V
0
10k
100k
1M
FREQUENCY (Hz)
FIGURE 11. AMPLIFIER “B” (OP-AMP) FREQUENCY
RESPONSE vs SUPPLY VOLTAGE
FN6345 Rev 3.00
May 14, 2009
5M
100
1k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 12. AMPLIFIER “B” (OP-AMP) FREQUENCY
RESPONSE vs SUPPLY VOLTAGE
Page 6 of 18
ISL28274, ISL28474
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
80
600
60
400
40
I-BIAS (pA)
100
800
VOS (µV)
1000
200
0
-200
-400
-800
-1000
-1
0
1
2
3
VCM (V)
0
-20
-60
-80
4
5
-100
-1
6
FIGURE 13. INPUT OFFSET VOLTAGE vs COMMON MODE
INPUT VOLTAGE
80
100
80
40
80
40
0
-40
-80
-40
-80
GAIN (dB)
120
0
1
10
1k
100
10k
100k
1M
0
1
PSRR (dB)
-20
-30
PHASE
60
50
40
0
20
GAIN
-100
100
0
-20
-60
PSRR +
100k
-150
1M
-40
-50
-60
-70
-80
-80
-90
-90
-100
-100
1k
10k
100k
1M
TEMPERATURE (°C)
FIGURE 17. AMPLIFIER “B” (OP AMP) PSRR vs FREQUENCY
V+, V- = ±2.5VDC
VSOURCE = 1VP-P
RL = 10k
-30
-70
FN6345 Rev 3.00
May 14, 2009
10k
1k
FIGURE 16. AMPLIFIER “B” (OP AMP) AVOL vs FREQUENCY
@ 1k LOAD
-10
-50
100
-50
10
PSRR -
10
100
FREQUENCY (Hz)
V+ = 5VDC
VSOURCE = 1VP-P
RL = 10k
AV = +1
-40
6
150
-20
10
-120
10M
CMRR (dB)
-10
5
0
FIGURE 15. AMPLIFIER “B” (OP AMP) AVOL vs FREQUENCY
@ 100k LOAD
0
4
200
FREQUENCY (Hz)
10
2
3
VCM (V)
FIGURE 14. INPUT BIAS CURRENT vs COMMON-MODE
INPUT VOLTAGE
PHASE (°)
GAIN (dB)
20
-40
V+ = 5V
RL = OPEN
RF = 100k, RG = 100
AV = +1000
-600
V+ = 5V
RL = OPEN
RF= 100k, RG = 100
AV = +1000
PHASE (°)
Typical Performance Curves
10
100
1k
10k
100k
1M
TEMPERATURE (°C)
FIGURE 18. AMPLIFIER “B” (OP AMP) CMRR vs FREQUENCY
Page 7 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
2.56
5
VIN
2.54
V+ = 5VDC
VOUT = 2VP-P
RL = 1k
AV = -2
4
3
VOUT
2.50
VOLTS (V)
VOLTS (V)
2.52
2.48
V+ = 5VDC
VOUT = 0.1VP-P
2.46
0
2
4
6
8
10
VIN
0
AV = +1
2.42
2
1
RL = 1k
2.44
12
14
16
18
-1
20
0
50
100
150
TIME (µs)
TIME (µs)
250
1k
VOLTAGE NOISE (nV/Hz)
10.00
CURRENT NOISE (pA/Hz)
200
FIGURE 20. AMPLIFIER “B” (OP AMP) LARGE SIGNAL
TRANSIENT RESPONSE
FIGURE 19. AMPLIFIER “B” (OP AMP) SMALL SIGNAL
TRANSIENT RESPONSE
1.00
0.10
0.01
VOUT
100
10
1
1
10
100
1k
10k
100k
1
10
100
FIGURE 22. AMPLIFIER “B” (OP AMP) VOLTAGE NOISE vs
FREQUENCY
6
V+ = 5V
VIN
5
VOLTS (V)
VOLTAGE NOISE (1µV/DIV)
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
FIGURE 21. AMPLIFIER “B” (OP AMP) CURRENT NOISE vs
FREQUENCY
10k
1k
4
100K
100K
3
DUT
+
VOUT
1K
VS -
Function
Generator
33140A
2
1
5.4µVP-P
0
TIME (1s/DIV)
FIGURE 23. AMPLIFIER “B” (OP AMP) 0.1Hz TO 10Hz INPUT
VOLTAGE NOISE
FN6345 Rev 3.00
May 14, 2009
VS+
-
0
50
100
150
200
TIME (ms)
FIGURE 24. AMPLIFIER “B” (OP AMP) INPUT VOLTAGE SWING
ABOVE THE V+ SUPPLY
Page 8 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
155
1V/DIV
SUPPLY CURRENT (µA)
AV = -1
VIN = 200mVP-P
V+ = 5V
V- = 0V
EN
INPUT
135
115
95
0
55
35
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VOUT
0.1V/DIV
75
0
SUPPLY VOLTAGE (V)
10µs/DIV
FIGURE 25. SUPPLY CURRENT vs SUPPLY VOLTAGE
170
FIGURE 26. AMPLIFIER “B” (OP AMP) TO OUTPUT DELAY
TIME
-4.0
n = 100
n = 100
160
MAX
-4.5
MAX
140
CURRENT (µA)
CURRENT (µA)
150
MEDIAN
130
120
110
100
80
-40
-20
0
20
40
60
80
100
-6.5
-40
120
TEMPERATURE (°C)
-20
0
20
40
60
80
100
120
FIGURE 28. DISABLED NEGATIVE SUPPLY CURRENT vs
TEMPERATURE, V+, V- = ±2.5V, RL = INF
40
50
n = 100
MIN
n = 100
MIN
20
0
0
-50
IA FB- IBIAS (pA)
IA FB+ IBIAS (pA)
MIN
TEMPERATURE (°C)
FIGURE 27. TOTAL SUPPLY CURRENT vs TEMPERATURE,
V+, V- = ±2.5V, RL = INF
-100
-150
MEDIAN
-200
-20
0
20
40
60
80
100
-40
-60
-80
MEDIAN
-100
MAX
-140
120
TEMPERATURE (°C)
FIGURE 29. IBIAS (IA FB+) vs TEMPERATURE, V+, V- = ±2.5V
FN6345 Rev 3.00
May 14, 2009
-20
-120
MAX
-250
-300
-40
-5.5
-6.0
MIN
90
MEDIAN
-5.0
-160
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 30. IBIAS (IA FB-) vs TEMPERATURE, V+, V- = ±2.5V.
Page 9 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
25
50
n = 100
n = 100
0
MIN
-75
IA FB- IBIAS (pA)
IA FB+ IBIAS (pA)
-25
-125
-175
MEDIAN
-225
-275
-40
0
20
40
60
80
-100
MEDIAN
-150
MAX
-200
MAX
-20
MIN
-50
100
-250
-40
120
-20
0
TEMPERATURE (°C)
50
120
n = 100
MEDIAN
IA IN- IBIAS (pA)
IA IN+ IBIAS (pA)
100
0
MIN
-150
-200
-250
MAX
-300
-20
0
20
40
60
80
-50
MIN
-100
-150
MEDIAN
-200
MAX
-250
100
-300
-40
120
-20
0
TEMPERATURE (°C)
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 34. IBIAS (IA IN-) vs TEMPERATURE, V+, V- = ±2.5V
FIGURE 33. IBIAS (IA IN+) vs TEMPERATURE, V+, V- = ±2.5V
50
50
n = 100
0
n = 100
-50
MIN
-100
-150
MEDIAN
-200
MAX
-250
-20
0
20
40
60
80
100
-50
MIN
-100
MEDIAN
-150
MAX
-200
120
TEMPERATURE (°C)
FIGURE 35. IBIAS (IA IN+) vs TEMPERATURE, V+, V- = ±1.2V
FN6345 Rev 3.00
May 14, 2009
IA IN- IBIAS (pA)
0
OU
IA IN+ IBIAS (pA)
80
50
-100
-300
-40
60
n = 100
0
-350
-40
40
FIGURE 32. IBIAS (IA FB-) vs TEMPERATURE, V+, V- = ±1.2V
FIGURE 31. IBIAS (IA FB+) vs TEMPERATURE, V+, V- = ±1.2V
-50
20
TEMPERATURE (°C)
-250
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 36. IBIAS (IA IN-) vs TEMPERATURE, V+, V- = ±1.2V
Page 10 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
50
30
n = 100
n = 100
10
0
-10
MIN
IN- IBIAS (pA)
IN+ IBIAS (pA)
-50
-100
MEDIAN
-150
-50
MIN
-70
-90
MEDIAN
-110
MAX
-200
-30
MAX
-130
-250
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
-150
-40
120
60
80
100
120
n = 100
-10
-10
-60
IN- IBIAS (pA)
-110
-160
MIN
-60
MIN
MEDIAN
-210
MEDIAN
-110
MAX
-160
-210
MAX
-260
-260
-20
0
20
40
60
80
100
-310
-40
120
-20
0
TEMPERATURE (°C)
FIGURE 39. IBIAS (IN+) vs TEMPERATURE, V+, V- = ±1.2V
40.0
MAX
20.0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 40. IBIAS (IN-) vs TEMPERATURE, V+, V- = ±1.2V
50
n = 100
n = 100
40
30
-20.0
IA IOS (pA)
0.0
IA IOS (pA)
40
40
n = 100
MIN
-40.0
MEDIAN
-60.0
-80.0
20
10
MAX
0
-10
-20
-100.0
-30
-120.0
-140.0
-40
20
FIGURE 38. IBIAS (IN-) vs TEMPERATURE, V+, V- = ±2.5V
40
IN+ IBIAS (pA)
0
TEMPERATURE (°C)
FIGURE 37. IBIAS (IN+) vs TEMPERATURE, V+, V- = ±2.5V
-310
-40
-20
MEDIAN
MIN
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 41. IA INPUT OFFSET CURRENT vs TEMPERATURE,
V+, V- = ±2.5V
FN6345 Rev 3.00
May 14, 2009
-50
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 42. IA INPUT OFFSET CURRENT vs TEMPERATURE,
V+, V- = ±1.2V
Page 11 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
100
40
n = 100
n = 100
MAX
20
MAX
50
0
-50
-40
-60
MEDIAN
-100
-150
-200
-40
-20
IOS (pA)
IOS (pA)
0
-80
-100
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
100
-1400
-40
120
MIN
IA VOS (µV)
IA VOS (µV)
-200
MEDIAN
-400
80
100
120
n = 100
MIN
200
0
-200
MEDIAN
-600
MAX
-20
0
20
40
60
80
TEMPERATURE (°C)
100
-800
-40
120
-20
0
20
40
60
80
100
120
FIGURE 46. IA INPUT OFFSET VOLTAGE vs TEMPERATURE
V+, V- = ±1.2V
500
n = 100
400
300
MAX
TEMPERATURE (°C)
FIGURE 45. IA INPUT OFFSET VOLTAGE vs TEMPERATURE,
V+, V- = ±2.5V
n = 100
MIN
300
MIN
200
200
100
100
VOS (µV)
VOS (µV)
60
-400
-600
0
MEDIAN
-200
0
-100
MEDIAN
-200
-300
-300
MAX
-400
-500
-40
40
400
0
-100
20
600
200
400
0
800
n = 100
400
500
-20
FIGURE 44. INPUT OFFSET CURRENT vs TEMPERATURE,
V+, V- = ±1.2V
600
-800
-40
MIN
TEMPERATURE (°C)
FIGURE 43. INPUT OFFSET CURRENT vs TEMPERATURE,
V+, V- = ±2.5V
800
MEDIAN
-120
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 47. INPUT OFFSET VOLTAGE vs TEMPERATURE,
V+, V- = ±2.5V
FN6345 Rev 3.00
May 14, 2009
MAX
-400
-500
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 48. INPUT OFFSET VOLTAGE vs TEMPERATURE,
V+, V- = ±1.2V
Page 12 of 18
ISL28274, ISL28474
Typical Performance Curves
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
140
145
n = 100
n = 100
135
130
115
CMRR (dB)
MIN
125
IA CMRR (dB)
MIN
MEDIAN
105
120
110
MEDIAN
100
95
MAX
90
85
75
-40
MAX
-20
0
20
40
60
80
100
80
-40
120
-20
0
20
TEMPERATURE (°C)
FIGURE 49. IA CMRR vs TEMPERATURE,
VCM = +2.5V TO -2.5V
155
155
n = 100
115
MEDIAN
105
95
120
MIN
125
MEDIAN
115
105
MAX
95
MAX
85
85
-20
0
20
40
60
80
100
75
-40
120
-20
0
TEMPERATURE (°C)
4.910
4.9975
MIN
MIN
IA VOUT (V)
4.890
4.880
MEDIAN
4.9970
4.9965
4.9960
MEDIAN
MAX
MAX
4.9955
4.850
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 53. IA VOUT HIGH vs TEMPERATURE, RL = 1k,
V+, V- = ±2.5V
FN6345 Rev 3.00
May 14, 2009
120
n = 100
4.900
-20
100
4.9980
n = 100
4.860
20
40
60
80
TEMPERATURE (°C)
FIGURE 52. PSRR vs TEMPERATURE, V+, V- = ±2.5V
FIGURE 51. IA PSRR vs TEMPERATURE, V+, V- = ±2.5V
IA VOUT (V)
100
n = 100
135
PSRR (dB)
IA PSRR (dB)
MIN
125
4.840
-40
80
145
135
4.870
60
FIGURE 50. CMRR vs TEMPERATURE, VCM = +2.5V TO -2.5V
145
75
-40
40
TEMPERATURE (°C)
4.9950
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 54. IA VOUT HIGH vs TEMPERATURE, RL = 100k,
V+, V- = ±2.5V
Page 13 of 18
ISL28274, ISL28474
Typical Performance Curves
170
V+ = +5V, V- = GND, VCM = 1/2V+, TA = +25°C, unless otherwise specified. (Continued)
6.5
n = 100
n = 100
160
6.0
MIN
IA VOUT (mV)
IA VOUT (mV)
150
140
130
MEDIAN
120
5.5
MIN
5.0
MEDIAN
4.5
110
MAX
90
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
4.910
3.5
-40
120
FIGURE 55. IA VOUT LOW vs TEMPERATURE, RL = 1k,
V+, V- = ±2.5V
20
40
60
80
TEMPERATURE (°C)
100
120
n = 100
4.9984
4.9982
MIN
MIN
4.9980
VOUT (V)
VOUT (V)
0
4.9986
4.890
4.880
4.870
-20
FIGURE 56. IA VOUT LOW vs TEMPERATURE, RL = 100k,
V+, V- = ±2.5V
n = 100
4.900
MAX
4.0
100
MEDIAN
4.9978
4.9976
4.9974
MEDIAN
4.9972
4.860
MAX
4.9970
MAX
4.9968
4.850
-40
-20
0
20
40
60
80
100
120
4.9966
-40
-20
0
TEMPERATURE (°C)
FIGURE 57. VOUT HIGH vs TEMPERATURE, RL = 1k,
V+, V- = ±2.5V
170
n = 100
4.4
n = 100
MIN
4.0
130
VOUT (mV)
VOUT (mV)
120
4.2
MIN
140
MEDIAN
120
MAX
110
3.8
3.6
MEDIAN
3.4
MAX
3.2
100
90
-40
100
FIGURE 58. VOUT HIGH vs TEMPERATURE, RL = 100k,
V+, V- = ±2.5V
160
150
20
40
60
80
TEMPERATURE (°C)
-20
0
20
40
60
80
100
TEMPERATURE (°C)
FIGURE 59. VOUT LOW vs TEMPERATURE, RL = 1k,
V+, V- = ±2.5V
FN6345 Rev 3.00
May 14, 2009
120
3.0
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 60. VOUT LOW vs TEMPERATURE RL = 100k, V+, V= ±2.5V
Page 14 of 18
ISL28274, ISL28474
Pin Descriptions
ISL28274
ISL28474
(16 LD QSOP) (24 LD QSOP)
1, 9, 13, 14
PIN NAME
EQUIVALENT
CIRCUIT
DESCRIPTION
11, 14
NC
Circuit 2
Instrumentation Amplifier output
1, 24
IA OUT
IA OUT_1
IA OUT_2
IA FB+
IA FB+_1
IA FB+_2
Circuit 1
Instrumentation Amplifier Feedback from non-inverting output
2, 23
IA FBIA FB-_1
IA FB-_2
Circuit 1
Instrumentation Amplifier Feedback from inverting output
3, 22
IA INIA IN-_1
IA IN-_2
Circuit 1
Instrumentation Amplifier inverting input
4, 21
IA IN+
IA IN+_1
IA IN+_2
Circuit 1
Instrumentation Amplifier non-inverting input
5, 20
7
6, 19
DNC
8
18
V-
10
8, 17
DNC
Circuit 1
Amplifier non-inverting input
9, 16
IN+
IN+ 1
IN+ 2
ININ- 1
IN- 2
Circuit 1
Amplifier inverting input
10, 15
OUT
OUT 1
OUT 2
Circuit 2
Amplifier output
12, 13
7
V+
Circuit 3
Positive power supply
2
3
4
5
6
11
12
15
16
No internal connection
Do Not Connect, Internal connection - Must be left floating
Circuit 3
Negative power supply
Do Not Connect, Internal connection - Must be left floating
IA = Instrumentation Amplifier
V+
IN-
V+
V-
V-
VCIRCUIT 2
Description of Operation and Application
Information
Product Description
The ISL28274 and ISL28474 provide both a micropower
instrumentation amplifier (Amp A) and a low power precision
amplifier (Amp B) in the same package. The amplifiers deliver
rail-to-rail input amplification and rail-to-rail output swing on a
single 2.4V to 5V supply. They also deliver excellent DC and
AC specifications while consuming only 60µA typical supply
current per amplifier. Because the instrumentation amplifiers
provide an independent pair of feedback terminals to set the
gain and to adjust the output level, the in-amp achieves high
FN6345 Rev 3.00
May 14, 2009
CAPACITIVELY
COUPLED
ESD CLAMP
OUT
IN+
CIRCUIT 1
V+
CIRCUIT 3
common-mode rejection ratio regardless of the tolerance of the
gain setting resistors. The instrumentation amplifier is internally
compensated for a minimum closed loop gain of 100 or
greater.
Input Protection
The input and feedback terminals have internal ESD protection
diodes to both positive and negative supply rails, limiting the
input voltage to within one diode drop beyond the supply rails.
If overdriving the inputs is necessary, the external input current
must never exceed 5mA. An external series resistor may be
used as a protection to limit excessive external voltage and
current from damaging the inputs.
Page 15 of 18
ISL28274, ISL28474
Input Stage and Input Voltage Range
Reference Connection
The input terminals (IN+ and IN-) of both amplifiers “A” and “B”
are single differential pair P-MOSFET devices aided by an
Input Range Enhancement Circuit to increase the headroom of
operation of the common-mode input voltage. The feedback
terminals (FB+ and FB-) of amplifier “A” also have a similar
topology. As a result, the input common-mode voltage range is
rail-to-rail. These amps are able to handle input voltages that
are at or slightly beyond the supply and ground making them
well suited for single 5V or 3.3V low voltage supply systems.
There is no need then to move the common-mode input to
achieve symmetrical input voltage.
Unlike a three-op amp instrumentation amplifier, a finite series
resistance seen at the REF terminal does not degrade the high
CMRR performance, eliminating the need for an additional
external buffer amplifier. Figure 62 uses the FB+ pin to provide
a high impedance REF terminal.
A pair of complementary MOSFET devices drives the output
VOUT to within a few mV of the supply rails. At a 100k load,
the PMOS sources current and pulls the output up to 4mV
below the positive supply, while the NMOS sinks current and
pulls the output down to 3mV above the negative supply, or
ground in the case of a single supply operation. The current
sinking and sourcing capability of the ISL28274 are internally
limited to 31mA.
Gain Setting of Instrumentation Amp “A”
VIN, the potential difference across IN+ and IN-, is replicated
(less the input offset voltage) across FB+ and FB-. The goal of
the ISL28274 in-amp is to maintain the differential voltage
across FB+ and FB- equal to IN+ and IN-;
(FB+ - FB-) = (IN+ - IN-). Consequently, the transfer function
can be derived. The gain is set by two external resistors, the
feedback resistor RF, and the gain resistor RG.
2.4V TO 5V
16
6 IN+
5 IN-
VIN/2
3 FB+
VCM
4 FB-
+
+
7
AMP “A”
V+
ISL28274
-
2
16
VIN/2
6 IN+
5 IN-
VIN/2
VOUT
4 FB-
2.4V to 5V
+
VOUT
V8
R1
R2
RG
RF
FIGURE 62. GAIN SETTING AND REFERENCE CONNECTION
RF 
RF 


VOUT =  1 + --------  VIN  +  1 + --------  VREF 
R
R


G
G
(EQ. 2)
The FB+ pin is used as a REF terminal to center or to adjust
the output. Because the FB+ pin is a high impedance input, an
economical resistor divider can be used to set the voltage at
the REF terminal without degrading or affecting the CMRR
performance. Any voltage applied to the REF terminal will shift
VOUT by VREF times the closed loop gain, which is set by
resistors RF and RG as shown in Figure 62.
The FB+ pin can also be connected to the other end of resistor,
RG. See Figure 63. Keeping the basic concept that the in-amps
maintain constant differential voltage across the input terminals
and feedback terminals (IN+ - IN- = FB+ - FB-), the transfer
function of Figure 63 can be derived.
V-
2.4V TO 5V
16
6 IN+
RF
5 IN-
VIN/2
FIGURE 61. GAIN IS BY EXTERNAL RESISTORS RF AND RG
3 FB+
VCM
4 FB-
+
+
7
V+
ISL28274
-
AMP “A”
2
VOUT
V8
(EQ. 1)
In Figure 61, the FB+ pin and one end of resistor RG are
connected to GND. With this configuration, Equation 1 is only
true for a positive swing in VIN; negative input swings will be
ignored and the output will be at ground.
FN6345 Rev 3.00
May 14, 2009
2
REF
VIN/2
RF 

VOUT =  1 + -------- VIN
R G

AMP “A”
ISL28274
-
8
RG
7
V+
+
-
3 FB+
VCM
Output Stage and Output Voltage Range
VIN/2
2.4V TO 5V
RG
RF
VREF
FIGURE 63. REFERENCE CONNECTION WITH AN AVAILABLE
VREF
Page 16 of 18
ISL28274, ISL28474
RF 

VOUT =  1 + --------  VIN  +  VREF 
R

G
(EQ. 3)
HIGH IMPEDANCE INPUT
A finite resistance RS in series with the VREF source, adds an
output offset of VIN*(RS/RG). As the series resistance RS
approaches zero, the gain equation is simplified to Equation 3
for Figure 63. VOUT is simply shifted by an amount VREF.
V+
IN
1/2 ISL28274
1/4 ISL28474
External Resistor Mismatches
Because of the independent pair of feedback terminals
provided by the ISL28274, the CMRR is not degraded by any
resistor mismatches. Hence, unlike a three op amp and
especially a two op amp in-amp, the ISL28274 reduces the
cost of external components by allowing the use of 1% or more
tolerance resistors without sacrificing CMRR performance. The
ISL28274 CMRR will be 100dB regardless of the tolerance of
the resistors used.
The ISL28274 has no internal current-limiting circuitry. If the
output is shorted, it is possible to exceed the Absolute
Maximum Rating for output current or power dissipation,
potentially resulting in the destruction of the device.
Using Only the Instrumentation Amplifier
Power Dissipation
If the application only requires the instrumentation amp, the
user must configure the unused op amp to prevent it from
oscillating. The unused op amp will oscillate if the input and
output pins are floating. This will result in higher than expected
supply currents and possible noise injection into the in-amp.
The proper way to prevent this oscillation is to short the output
to the negative input and ground the positive input (as shown
in Figure 64).
It is possible to exceed the +150°C maximum junction
temperatures under certain load and power-supply conditions.
It is therefore important to calculate the maximum junction
temperature (TJMAX) for all applications to determine if power
supply voltages, load conditions, or package type need to be
modified to remain in the safe operating area. These
parameters are related in Equation 4:
FIGURE 65. GUARD RING EXAMPLE FOR UNITY GAIN
AMPLIFIER
Current Limiting
T JMAX = T MAX +   JA xPD MAXTOTAL 
-
where:
+
• PDMAXTOTAL is the sum of the maximum power dissipation
of each amplifier in the package (PDMAX)
FIGURE 64. PREVENTING OSCILLATIONS IN UNUSED
CHANNELS
Proper Layout Maximizes Performance
To achieve the maximum performance of the high input
impedance and low offset voltage, care should be taken in the
circuit board layout. The PC board surface must remain clean
and free of moisture to avoid leakage currents between
adjacent traces. Surface coating of the circuit board will reduce
surface moisture and provide a humidity barrier, reducing
parasitic resistance on the board. When input leakage current
is a concern, the use of guard rings around the amplifier inputs
will further reduce leakage currents. Figure 65 shows a guard
ring example for a unity gain amplifier that uses the low
impedance amplifier output at the same voltage as the high
impedance input to eliminate surface leakage. The guard ring
does not need to be a specific width, but it should form a
continuous loop around both inputs. For further reduction of
leakage currents, components can be mounted to the PC
board using Teflon standoff insulators.
FN6345 Rev 3.00
May 14, 2009
(EQ. 4)
• PDMAX for each amplifier can be calculated as shown in
Equation 5:
V OUTMAX
PD MAX = 2*V S  I SMAX +  V S - V OUTMAX   ---------------------------RL
(EQ. 5)
where:
• TMAX = Maximum ambient temperature
• JA = Thermal resistance of the package
• PDMAX = Maximum power dissipation of 1 amplifier
• VS = Supply voltage (Magnitude of V+ and V-)
• IMAX = Maximum supply current of 1 amplifier
• VOUTMAX = Maximum output voltage swing of the
application
• RL = Load resistance
Page 17 of 18
ISL28274, ISL28474
Quarter Size Outline Plastic Packages Family (QSOP)
MDP0040
A
QUARTER SIZE OUTLINE PLASTIC PACKAGES FAMILY
D
(N/2)+1
N
INCHES
SYMBOL QSOP16 QSOP24 QSOP28 TOLERANCE NOTES
E
PIN #1
I.D. MARK
E1
1
(N/2)
B
0.010
C A B
e
H
C
SEATING
PLANE
0.007
0.004 C
b
C A B
A
0.068
0.068
0.068
Max.
-
A1
0.006
0.006
0.006
±0.002
-
A2
0.056
0.056
0.056
±0.004
-
b
0.010
0.010
0.010
±0.002
-
c
0.008
0.008
0.008
±0.001
-
D
0.193
0.341
0.390
±0.004
1, 3
E
0.236
0.236
0.236
±0.008
-
E1
0.154
0.154
0.154
±0.004
2, 3
e
0.025
0.025
0.025
Basic
-
L
0.025
0.025
0.025
±0.009
-
L1
0.041
0.041
0.041
Basic
-
N
16
24
28
Reference
Rev. F 2/07
NOTES:
L1
A
1. Plastic or metal protrusions of 0.006” maximum per side are not
included.
2. Plastic interlead protrusions of 0.010” maximum per side are not
included.
c
SEE DETAIL "X"
3. Dimensions “D” and “E1” are measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994.
0.010
A2
GAUGE
PLANE
L
A1
4°±4°
DETAIL X
© Copyright Intersil Americas LLC 2006-2009. All Rights Reserved.
All trademarks and registered trademarks are the property of their respective owners.
For additional products, see www.intersil.com/en/products.html
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets are
current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its
subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
FN6345 Rev 3.00
May 14, 2009
Page 18 of 18
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