DATASHEET

ISL28176, ISL28276, ISL28476
®
Data Sheet
June 23, 2009
Single, Dual and Quad Micropower Single
Supply Rail-to-Rail Input and Output
(RRIO) Precision Op Amp
The ISL28176, ISL28276 and ISL28476 are single, dual and
quad channel micropower operational amplifiers optimized
for single supply operation over the 2.4V to 5V range. They
can be operated from one lithium cell or two Ni-Cd batteries.
These devices feature an Input Range Enhancement Circuit
(IREC) which enables them to maintain CMRR performance for
input voltages 10% above the positive supply rail and down to
the negative supply. The output operation is rail-to-rail.
The ISL28276 and ISL28476 draw minimal supply current
while meeting excellent DC-accuracy, AC-performance,
noise and output drive specifications. The ISL28276 (QSOP
package only) contains a power-down enable pin that
reduces the power supply current to typically 4µA in the
disabled state.
FN6301.4
Features
• Low power 120µA typical supply current (ISL28276)
• 100µV maximum offset voltage
• 500pA typical input bias current
• 400kHz typical gain-bandwidth product
• 115dB typical PSRR and CMRR
• Single supply operation down to 2.4V
• Input is capable of swinging above V+ and to V- (ground
sensing)
• Rail-to-rail input and output (RRIO)
• Pb-free (RoHS compliant)
Applications
• Battery- or solar-powered systems
• 4mA to 25mA current loops
Ordering Information
PART NUMBER
(Note)
PART
MARKING
• Handheld consumer products
PACKAGE
(Pb-free)
PKG.
DWG. #
ISL28176FBZ*
28176 FBZ
8 Ld SOIC
MDP0027
ISL28276FBZ*
28276 FBZ
8 Ld SOIC
MDP0027
ISL28276IAZ*
28276 IAZ
16 Ld QSOP MDP0040
ISL28476FAZ*
28476 FAZ
16 Ld QSOP MDP0040
• Medical devices
• Thermocouple amplifiers
• Photodiode pre-amps
• pH probe amplifiers
*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.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2006, 2007, 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
ISL28176, ISL28276, ISL28476
Pinouts
ISL28276
(16 LD QSOP)
TOP VIEW
ISL28176
(8 LD SOIC)
TOP VIEW
NC 1
IN-_A 2
NC 1
16 NC
7 V+
NC 2
15 V+
6 OUT_A
OUT_A 3
14 OUT_B
V- 4
5 NC
IN-_A 4
13 IN-_B
IN+_A 5
12 IN+_B
EN_A 6
11 EN_B
V- 7
10 NC
NC 8
9 NC
ISL28476
(16 LD QSOP)
TOP VIEW
ISL28276
(8 LD SOIC)
TOP VIEW
8 V+
OUT_A 1
16 OUT_D
+
OUT_A 1
+
+
IN+_A 3
+
8 NC
IN-_A 2
IN+_A 3
6 IN-_B
IN+_A 3
V- 4
5 IN+_B
V+ 4
+
15 IN-_D
+
IN-_A 2
+
7 OUT_B
14 IN+_D
13 V-
OUT_B 7
NC 8
2
+
-
IN-_B 6
12 IN+_C
+
-
IN+_B 5
11 IN-_C
10 OUT_C
9 NC
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Absolute Maximum Ratings (TA = +25°C)
Thermal Information
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V
Supply Turn On Voltage Slew Rate . . . . . . . . . . . . . . . . . . . . . 1V/µs
Differential Input Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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)
θJA (°C/W)
8 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . .
125
16 Ld QSOP Package . . . . . . . . . . . . . . . . . . . . . . .
100
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 . . . . . . . . . . . . . . . . . . . . . +150°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.
NOTE:
1. θJA 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
V+ = 5V, V- = 0V,VCM = 2.5V, RL = Open, TA = +25°C unless otherwise specified.
Boldface limits apply over the operating temperature range, -40°C to +125°C, temperature data
established by characterization.
DESCRIPTION
CONDITIONS
MIN
(Note 2)
TYP
MAX
(Note 2)
UNIT
DC SPECIFICATIONS
VOS
Input Offset Voltage
ΔV OS
--------------ΔT
Input Offset Voltage vs Temperature
IOS
Input Offset Current
ISL28176
-100
-220
±20
100
220
µV
ISL28276
-100
-150
±20
100
150
µV
ISL28476
-100
-225
±20
100
225
µV
ISL28176
0.7
µV/°C
ISL28276, ISL28476
0.5
µV/°C
ISL28176
ISL28276, ISL28476
IB
Input Bias Current
ISL28176
ISL28276, ISL28476
-1
-2
±0.4
1.3
2
nA
-1.3
-4
±0.25
1
4
nA
-2
-5
±0.5
2
5
nA
-2
-2.5
±0.5
2
2.5
nA
5
V
CMIR
Common-Mode Voltage Range
Guaranteed by CMRR
0
CMRR
Common-Mode Rejection Ratio
VCM = 0V to 5V
90
80
115
dB
PSRR
Power Supply Rejection Ratio
V+ = 2.4V to 5V
90
80
115
dB
3
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Electrical Specifications
PARAMETER
AVOL
VOUT
V+ = 5V, V- = 0V,VCM = 2.5V, RL = Open, TA = +25°C unless otherwise specified.
Boldface limits apply over the operating temperature range, -40°C to +125°C, temperature data
established by characterization. (Continued)
DESCRIPTION
Large Signal Voltage Gain
Maximum Output Voltage Swing
ISL28176
CONDITIONS
MIN
(Note 2)
Supply Current, Enabled
UNIT
200
200
500
V/mV
ISL28276, ISL28476
VO = 0.5V to 4.5V, RL = 100kΩ
350
350
550
V/mV
ISL28176,
VO = 0.5V to 4.5V, RL = 1kΩ
25
V/mV
ISL28276, ISL28476
VO = 0.5V to 4.5V, RL = 1kΩ
95
V/mV
Output low, RL = 100kΩ
3
8
10
mV
130
200
300
mV
Output high, RL = 100kΩ
4.994
4.992
4.997
V
Output high, RL = 1kΩ
4.750
4.7
4.867
V
Output low, RL = 100kΩ
Output low, RL = 1kΩ
IS,ON
MAX
(Note 2)
ISL28176
VO = 0.5V to 4.5V, RL = 100kΩ
Output low, RL = 1kΩ
Maximum Output Voltage Swing
ISL28276, ISL28476
TYP
3
6
30
mV
130
175
225
mV
Output high, RL = 100kΩ
4.990
4.97
4.996
V
Output high, RL = 1kΩ
4.800
4.750
4.880
V
35
30
55
75
90
µA
ISL28276, All channels enabled.
120
156
175
µA
ISL28476, All channels enabled.
240
315
350
µA
4
7
9
µA
ISL28176
IS,OFF
Supply Current, Disabled
ISL28276IAZ (QSOP package only),
All channels disabled.
ISC+
Short Circuit Sourcing Capability
ISL28176
RL = 10Ω
18
18
31
mA
ISL28276, ISL28476
RL = 10Ω
29
23
31
mA
ISL28176
RL = 10Ω
17
15
26
mA
ISL28276, ISL28476
RL = 10Ω
24
19
26
mA
2.4
ISC-
Short Circuit Sinking Capability
VSUPPLY
Supply Operating Range
V- to V+
VENH
EN Pin High Level
ISL28276IAZ, (QSOP package only)
VENL
EN Pin Low Level
ISL28276IAZ, (QSOP package only)
IENH
EN Pin Input High Current
VEN = V+
ISL28276IAZ, (QSOP package only)
4
5
2
V
V
0.7
0.8
V
1.3
1.5
µA
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Electrical Specifications
PARAMETER
IENL
V+ = 5V, V- = 0V,VCM = 2.5V, RL = Open, TA = +25°C unless otherwise specified.
Boldface limits apply over the operating temperature range, -40°C to +125°C, temperature data
established by characterization. (Continued)
DESCRIPTION
EN Pin Input Low Current
CONDITIONS
MIN
(Note 2)
VEN = VISL28276IAZ, (QSOP package only)
TYP
MAX
(Note 2)
UNIT
0
0.1
µA
AC SPECIFICATONS
GBW
Gain Bandwidth Product
AV = 100, RF = 100kΩ, RG = 1kΩ,
RL = 10kΩ to VCM
400
kHz
en
Input Noise Voltage Peak-to-Peak
ISL28176
f = 0.1Hz to 10Hz
1.5
µVP-P
ISL28276, ISL28476
f = 0.1Hz to 10Hz
2.5
µVP-P
ISL28176
fO = 1kHz
28
nV/√Hz
ISL28276, ISL28476
fO = 1kHz
30
nV/√Hz
ISL28176
fO = 1kHz
0.16
pA/√Hz
ISL28276, ISL28476
fO = 1kHz
0.12
pA/√Hz
Input Noise Voltage Density
in
Input Noise Current Density
CMRR @ 60Hz
Input Common Mode Rejection Ratio
ISL28276, ISL28476
VCM = 1VP-P, RL = 10kΩ to VCM
78
dB
PSRR+ @ 120Hz
Power Supply Rejection Ratio, +V
ISL28176
V+, V- = ±1.2V and ±2.5V,
VSOURCE = 1VP-P, RL = 10kΩ to VCM
90
dB
ISL28276, ISL28476
V+, V- = ±1.2V and ±2.5V,
VSOURCE = 1VP-P, RL = 10kΩ to VCM
105
dB
ISL28176
V+, V- = ±1.2V and ±2.5V
VSOURCE = 1VP-P, RL = 10kΩ to VCM
70
dB
ISL28276, ISL28476
V+, V- = ±1.2V and ±2.5V
VSOURCE = 1VP-P, RL = 10kΩ to VCM
73
dB
PSRR- @ 120Hz
Power Supply Rejection Ratio, -V
TRANSIENT RESPONSE
SR
Slew Rate
ISL28176
ISL28276, ISL28476
tEN
±0.065
±0.13
±0.3
V/µs
±0.10
±0.09
±0.17
±0.20
±0.25
V/µs
Enable to Output Turn-on Delay Time,
10% EN to 10% VOUT,
VEN = 5V to 0V, AV = -1,
Rg = Rf = RL = 1k to VCM, ISL28276IAZ,
(QSOP package only)
2
µs
Enable to Output Turn-off Delay Time,
10% EN to 10% VOUT
VEN = 0V to 5V, AV = -1,
Rg = Rf = RL = 1k to VCM, ISL28276IAZ,
(QSOP package only)
0.1
µs
NOTE:
2. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested.
5
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
2
+1
V+ = 2.5V
1
0
0
-1
-2
-2
GAIN (dB)
V+ = 5V
-3
-4
-5
RL = 10k
CL = 8.3pF
AV = +1
VOUT = 10mVP-P
-6
-7
-8
-9
1k
10k
V+, V- = ±2.5V
RL = 10k
-4
-5
V+ = 2V
VOUT = 50mVP-P
AV = 1
CL = 3pF
RF = 0/RG = INF
-6
-7
100k
FREQUENCY (Hz)
1M
-8
10M
FIGURE 1. ISL28176 GAIN vs FREQUENCY vs SUPPLY
VOLTAGE
1k
10k
100k
FREQUENCY (Hz)
1M
5M
FIGURE 2. ISL28276, ISL28476 FREQUENCY RESPONSE vs
SUPPLY VOLTAGE
45
45
40
40
35
V+ = 2.5V
35
30
25
GAIN (dB)
30
GAIN (dB)
-3
V+, V- = ±1.2V
RL = 10k
V+ = 5V
20
AV = 100
RL = 10k
CL = 8.3pF
VOUT = 10mVP-P
RF = 221kΩ
RG = 2.23kΩ
15
10
5
0
100
1k
25
15
V+ = 2V
10
5
10k
FREQUENCY (Hz)
100k
V+, V- = ±1.25V
20
AV = 100
V+, V- = ±2.5V
RL = 10kΩ
CL = 2.7pF
RF/RG = 99.02
V+, V- = ±1.0V
RF = 221kΩ
RG = 2.23kΩ
0
100
1M
FIGURE 3. ISL28176 GAIN vs FREQUENCY vs SUPPLY
VOLTAGE
1k
10k
100k
FREQUENCY (Hz)
1M
FIGURE 4. ISL28276, ISL28476 FREQUENCY RESPONSE vs
SUPPLY VOLTAGE
120
80
100
80
40
80
200
150
0
GAIN
0
-40
GAIN (dB)
40
PHASE (°)
GAIN (dB)
PHASE
100
60
50
40
0
20
GAIN
-50
PHASE
-40
-80
-80
1
10
100
1k
10k
100k
1M
-120
10M
FREQUENCY (Hz)
FIGURE 5. AVOL vs FREQUENCY @ 100kΩ LOAD
6
0
-20
10
PHASE (°)
GAIN (dB)
-1
V+, V- = ±1.2V
RL = 1k
V+, V- = ±2.5V
RL = 1k
-100
100
1k
10k
100k
-150
1M
FREQUENCY (Hz)
FIGURE 6. AVOL vs FREQUENCY @ 1kΩ LOAD
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
100
120
110
100
90
PSRR +
80
60
50
PSRR -
40
30
20
10
0
10
70
CMRR (dB)
80
70
PSRR (dB)
V+, V- = ±2.5V
VSOURCE = 1VP-P
RL = 100kΩ
AV = +1
90
60
50
40
V+, V- = ±2.5V
VSOURCE = 1VP-P
RL = 100kΩ
AV = +1
100
1k
30
20
10k
100k
10
10
1M
100
FREQUENCY (Hz)
FIGURE 7. PSRR vs FREQUENCY
VOLTAGE NOISE (nV/√Hz)
INPUT VOLTAGE NOISE (nV√Hz)
100
1
10
100
1k
FREQUENCY (Hz)
10k
100
10
100k
FIGURE 9. ISL28176 INPUT VOLTAGE NOISE DENSITY vs
FREQUENCY
1
10
100
1k
FREQUENCY (Hz)
100k
10k
FIGURE 10. ISL28276, ISL28476 VOLTAGE NOISE vs
FREQUENCY
10
10.0
V+ = 5V
RL = OPEN
CL = 8.3pF
AV = +1
CURRENT NOISE (pA/√Hz)
INPUT CURRENT NOISE (pA√Hz)
100k
1k
V+ = 5V
RL = OPEN
CL = 8.3pF
AV = +1
1
0.1
0.1
10k
FIGURE 8. CMRR vs FREQUENCY
1000
10
0.1
1k
FREQUENCY (Hz)
1
10
100
1k
FREQUENCY (Hz)
10k
100k
FIGURE 11. ISL28176 INPUT CURRENT NOISE DENSITY vs
FREQUENCY
7
1.0
0.1
1
10
100
1k
FREQUENCY (Hz)
10k
100k
FIGURE 12. ISL28276, ISL28476 CURRENT NOISE vs
FREQUENCY
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
1.5
2.0
VOLTAGE NOISE (0.5µV/DIV)
INPUT NOISE (µV)
V+ = 5V
R = OPEN
1.5 L
CL = 8.3pF
1.0 Rg = 10, Rf = 10k
AV = 1000
0.5
0
-0.5
-1.0
-1.5
-2.0
0
1
2
3
4
5
6
TIME (s)
7
8
9
10
0.5
0
-0.5
-1.0
-1.5
0
10
2.54
8
2.52
VOLTS (V)
2.56
V+, V- = ±2.5V
RL = 10k
CL = 8.3pF
Rg = Rf = 10k
AV = 2
VOUT = 10mVP-P
4
2
2
3
5
6
7
8
9
10
VIN
VOUT
2.50
2.48
V+ = 5VDC
VOUT = 0.1VP-P
RL = 500Ω
AV = +1
2.46
2.44
0
2.42
-2
0
50
100
150
200
250
TIME (µs)
300
350
0
400
2
4
6
8
10
12
14
16
18
20
TIME (µs)
FIGURE 15. ISL28176 SMALL SIGNAL TRANSIENT RESPONSE
FIGURE 16. ISL28276, ISL28476 SMALL SIGNAL TRANSIENT
RESPONSE
2.5
4.0
VIN
2.0
VOUT
3.5
1.5
V+ = 5VDC
VOUT = 2VP-P
RL = 1kΩ
AV = -1
1.0
0.5
VOLTS (V)
LARGE SIGNAL (V)
4
FIGURE 14. ISL28276, ISL28476 0.1Hz TO 10Hz INPUT
VOLTAGE NOISE
12
6
1
TIME (1s/DIV)
FIGURE 13. ISL28176 INPUT VOLTAGE NOISE 0.1Hz TO 10Hz
SMALL SIGNAL (mV)
1.0
V+, V- = ±2.5V
RL = 10k
CL = 8.3pF
Rg = 10k
Rf = 30k
AV = 4
VOUT = 4VP-P
0
-0.5
-1.0
-1.5
VOUT
100
150
200
250
TIME (µs)
300
350
FIGURE 17. ISL28176 LARGE SIGNAL TRANSIENT
RESPONSE
8
VIN
1.5
-2.5
50
2.5
2.0
-2.0
0
3.0
400
1.0
0
20
40
60
TIME (µs)
80
100
FIGURE 18. ISL28276, ISL28476 LARGE SIGNAL TRANSIENT
RESPONSE
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
100
AV = -1
VIN = 200mVP-P
V+ = 5V
V- = 0V
80
60
40
VOS (μV)
1V/DIV
EN
INPUT
0
0
-20
-40
VOUT
0.1V/DIV
20
V+ = 5V
RL = OPEN
RF = 100k, RG = 100
AV = +1000
-60
-80
0
-100
10µs/DIV
FIGURE 19. ISL28276 ENABLE TO OUTPUT DELAY TIME
-1
0
1
2
3
VCM (V)
4
5
6
FIGURE 20. INPUT OFFSET VOLTAGE vs COMMON-MODE
INPUT VOLTAGE
155
100
80
I-BIAS (nA)
40
20
0
-20
-40
-60
-80
-100
-1
V+ = 5V
RL = OPEN
RF = 100k, RG = 100
AV = +1000
0
1
135
SUPPLY CURRENT (µA)
60
2
3
VCM (V)
4
5
115
95
75
55
35
2.0
6
FIGURE 21. INPUT OFFSET CURRENT vs COMMON-MODE
INPUT VOLTAGE
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.5
150
n = 12
N=7
70
100
CURRENT (µA)
65
MAX
60
MIN
55
MAX
50
0
MEDIAN
-50
MIN
MEDIAN
50
45
-40
5.0
FIGURE 22. ISL28276 SUPPLY CURRENT vs SUPPLY VOLTAGE
75
SUPPLY CURRENT (µA)
2.5
-100
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 23. ISL28176 SUPPLY CURRENT vs TEMPERATURE
VS = ±2.5V ENABLED, RL = INF
9
-150
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 24. ISL28276 SUPPLY CURRENT vs TEMPERATURE,
V+,V- = ±2.5V ENABLED, RL = INF
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
4.9
320
N=7
N = 1000
4.7
MAX
280
MEDIAN
260
4.5
CURRENT (µA)
CURRENT (µA)
300
240
4.3
4.1
MAX
MEDIAN
3.9
MIN
220
3.7
200
-40
3.5
-40
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 25. ISL28476 SUPPLY CURRENT vs TEMPERATURE,
V+, V- = ±2.5V ENABLED, RL = INF
100
120
SO PACKAGE
n = 12
150
VOS (µV)
VOS (µV)
20
40
60
80
TEMPERATURE (°C)
200
SO PACKAGE
150
100
0
FIGURE 26. ISL28276 SUPPLY CURRENT vs TEMPERATURE,
V+, V- = ±2.5V DISABLED, RL = INF
200
n = 12
-20
MAX
MEDIAN
100
MAX
MEDIAN
50
50
MIN
0
0
MIN
-50
-40
-20
0
20
40
60
80
100
-50
-40
120
-20
0
20
FIGURE 27. ISL28176 INPUT OFFSET VOLTAGE vs
TEMPERATURE VS = ±2.5V
150
N=7
100
80
100
120
N=7
100
MAX
MAX
50
50
VOS (µV)
VOS (µV)
60
FIGURE 28. ISL28176 INPUT OFFSET VOLTAGE vs
TEMPERATURE VS = ±1.2V
150
MEDIAN
0
-50
MEDIAN
0
-50
MIN
MIN
-100
-150
-40
40
TEMPERATURE (°C)
TEMPERATURE (°C)
-100
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 29. ISL28276 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±2.5V
10
-150
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 30. ISL28276 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±1.2V
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
200
(Continued)
200
N = 1000
150
100
100
MAX
50
VOS (µV)
VOS (µV)
N = 1000
150
MEDIAN
0
-50
MAX
50
MEDIAN
0
-50
MIN
MIN
-100
-100
-150
-150
-200
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
-200
-40
120
FIGURE 31. ISL28476 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±2.5V
0
n = 12
CURRENT (nA)
1.5
MAX
1.0
0.5
MEDIAN
0
2.0
MAX
1.5
1.0
MEDIAN
0.5
0
MIN
MIN
-20
0
20
40
60
80
100
-0.5
-40
120
-20
0
TEMPERATURE (°C)
40
60
80
100
120
FIGURE 34. ISL28176 IBIAS (+) vs TEMPERATURE VS = ±1.2V
3.0
N = 1000
N = 1000
2.5
2.0
MAX
2.0
1.5
1.0
IBIAS+ (nA)
IBIAS+ (nA)
20
TEMPERATURE (°C)
FIGURE 33. ISL28176 IBIAS (+) vs TEMPERATURE VS = ±2.5V
MEDIAN
0.5
0
MIN
-0.5
MAX
1.5
1.0
MEDIAN
0.5
0
MIN
-0.5
-1.0
-1.5
-40
120
2.5
2.0
2.5
100
3.0
n = 12
-0.5
-40
20
40
60
80
TEMPERATURE (°C)
FIGURE 32. ISL28476 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±1.2V
2.5
CURRENT (nA)
-20
-1.0
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 35. ISL28276 ISL28476 IBIAS (+) vs TEMPERATURE,
V+,V- = ±2.5V
11
-1.5
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 36. ISL28276, ISL28476 IBIAS (+) vs TEMPERATURE,
V+,V- = ±1.2V
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
2.5
3.0
n = 12
2.5
1.5
CURRENT (nA)
CURRENT (nA)
2.0
MAX
1.0
MEDIAN
0.5
0
-20
0
20
2.0
MAX
1.5
1.0
MEDIAN
0.5
0
MIN
-0.5
-40
n = 12
40
60
80
100
-0.5
-40
120
MIN
-20
0
TEMPERATURE (°C)
FIGURE 37. ISL28176 IBIAS (-) vs TEMPERATURE VS = ±2.5V
2.5
2.5
1.0
IBIAS- (nA)
MEDIAN
0.5
0
MIN
-0.5
100
120
MAX
0
-1.5
-1.5
-20
0
20
40
60
80
TEMPERATURE (°C)
100
-2.0
-40
120
MEDIAN
-0.5
-1.0
FIGURE 39. ISL28276 ISL28476 IBIAS (-) vs TEMPERATURE,
V+, V- = ±2.5V
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 40. ISL28276, ISL28476 IBIAS (-) vs TEMPERATURE,
V+, V- = ±1.2V
2.5
2.5
n = 12
N = 1000
2.0
2.0
1.5
1.5
MAX
1.0
MAX
IOS (nA)
CURRENT (nA)
80
0.5
-1.0
1.0
0.5
0.5
MEDIAN
0
-0.5
MEDIAN
-1.0
0
MIN
MIN
-0.5
-40
60
1.5
1.0
IBIAS- (nA)
N = 1000
2.0
MAX
1.5
-2.0
-40
40
FIGURE 38. ISL28176 IBIAS (-) vs TEMPERATURE VS = ±1.2V
N = 1000
2.0
20
TEMPERATURE (°C)
-20
0
-1.5
20
40
60
80
TEMPERATURE (°C)
100
FIGURE 41. ISL28176 INPUT OFFSET CURRENT vs
TEMPERATURE, VS = ±2.5V
12
120
-2.0
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 42. ISL28276, ISL28476 IOS vs TEMPERATURE,
V+, V- = ±2.5V
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
900
(Continued)
1050
n = 12
N = 1000
800
MAX
MAX
950
850
600
500
AVOL (V/mV)
AVOL (V/mV)
700
MEDIAN
400
MIN
300
750
650
MEDIAN
550
200
450
100
0
-40
MIN
-20
0
20
40
60
80
100
350
-40
120
-20
0
TEMPERATURE (°C)
FIGURE 43. ISL28176 AVOL, RL = 100k, VS ±2.5V, VO = ±2V
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 44. ISL28276, ISL28476 AVOL vs TEMPERATURE,
V+, V- = ±2.5V, RL = 100k
125
135
n = 12
N = 1000
MAX
130
120
115
CMRR (dB)
CMRR (dB)
125
MAX
110
105
MEDIAN
120
MEDIAN
115
110
105
MIN
100
100
95
-40
MIN
-20
0
20
40
95
60
80
100
90
-40
120
-20
0
FIGURE 45. ISL28176 CMRR vs TEMPERATURE, VCM = +2.5V
TO -2.5V
140
40
60
80
100
120
FIGURE 46. ISL28276, ISL28476 CMRR vs TEMPERATURE,
VCM = +2.5V TO -2.5V V+, V- = ±2.5V
140
n = 12
N = 1000
135
MAX
130
130
MAX
125
PSRR (dB)
PSRR (dB)
20
TEMPERATURE (°C)
TEMPERATURE (°C)
120
115
MEDIAN
110
120
MEDIAN
110
MIN
100
105
100
95
-40
90
MIN
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 47. ISL28176 PSRR vs TEMPERATURE, VS = ±1.2V
TO ±2.5V
13
80
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 48. ISL28276, ISL28476 PSRR vs TEMPERATURE, V+,
V- = ±1.2V to ±2.5V
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
4.91
(Continued)
4.91
n = 12
N = 1000
4.90
MAX
4.90
4.89
MAX
MEDIAN
VOUT (V)
VOUT (V)
4.88
4.87
4.86
MIN
4.85
4.89
MEDIAN
4.88
4.87
MIN
4.84
4.86
4.83
4.82
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
FIGURE 49. ISL28176 VOUT HIGH vs TEMPERATURE,
V+, V- = ±2.5V, RL= 1k
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 50. ISL28276, ISL28476 VOUT HIGH vs
TEMPERATURE, V+,V- = ±2.5V, RL= 1k
170
n = 12
220
160
200
150
MEDIAN
MAX
180
160
140
VOUT (mV)
VOUT (mV)
240
4.85
-40
120
N = 1000
140
MAX
130
MEDIAN
MIN
120
MIN
120
110
100
100
80
-40
-20
0
20
40
60
80
100
90
-40
120
-20
0
39
N = 1000
37
MAX
33
MEDIAN
31
MIN
29
27
25
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 53. ISL28276, ISL28476 + OUTPUT SHORT CIRCUIT
CURRENT vs TEMPERATURE, VIN = -2.55V,
RL = 10, V+, V- = ±2.5V
14
40
60
80
100
120
FIGURE 52. ISL28276, ISL28476 VOUT LOW vs
TEMPERATURE, V+, V- = ±2.5V, RL= 1k
- OUTPUT SHORT CIRCUIT CURRENT
(mA)
+ OUTPUT SHORT CIRCUIT CURRENT
(mA)
FIGURE 51. ISL28176 VOUT LOW vs TEMPERATURE,
V+, V- = ±2.5V, RL= 1k
35
20
TEMPERATURE (°C)
TEMPERATURE (°C)
-21
N = 1000
-23
MAX
-25
-27
MEDIAN
MIN
-29
-31
-33
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 54. ISL28276, ISL28476 - OUTPUT SHORT CIRCUIT
CURRENT vs TEMPERATURE, VIN = +2.55V,
RL = 10, V+, V- = ±2.5V
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
0.24
0.23
N = 1000
n = 12
0.22
0.19
+ SLEW RATE (V/μs)
SLEW RATE (V/µs)
0.21
MAX
MEDIAN
0.17
0.15
0.13
MIN
0.11
0.20
MAX
0.18
0.16
MEDIAN
MIN
0.14
0.12
0.09
-40
-20
0
20
40
60
80
100
0.10
-40
120
-20
0
TEMPERATURE (°C)
FIGURE 55. ISL28176 + SLEW RATE vs TEMPERATURE,
VOUT = ±1.5V, AV = +2
120
0.24
N = 1000
n = 12
0.22
MAX
- SLEW RATE (V/μs)
CURRENT (pA)
100
FIGURE 56. ISL28276, ISL28476 + SLEW RATE vs
TEMPERATURE, VOUT = ±1.5V, AV = +2
0.17
0.16
20
40
60
80
TEMPERATURE (°C)
0.15
0.14
MEDIAN
0.13
MIN
0.12
0.11
0.10
-40
0.20
MAX
0.18
MEDIAN
0.16
MIN
0.14
0.12
-20
0
20
40
60
80
100
0.10
-40
120
-20
0
TEMPERATURE (°C)
FIGURE 57. ISL28176 - SLEW RATE vs TEMPERATURE, VOUT
= ±1.5V, AV = +2
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 58. ISL28276, ISL28476 - SLEW RATE vs
TEMPERATURE, VOUT = ±1.5V, AV = +2
Pin Descriptions
ISL28176
ISL28276
(8 LD SOIC) (8 LD SOIC)
ISL28276
(16 LD QSOP)
ISL28476
PIN
EQUIVALENT
(16 LD QSOP) NAME
CIRCUIT
DESCRIPTION
6
1
3
1
OUT_A
Circuit 3
Amplifier A output
2
2
4
2
IN-_A
Circuit 1
Amplifier A inverting input
3
3
5
3
IN+_A
Circuit 1
Amplifier A non-inverting input
7
8
15
4
V+
Circuit 4
Positive power supply
5
12
5
IN+_B
Circuit 1
Amplifier B non-inverting input
6
13
6
IN-_B
Circuit 1
Amplifier B inverting input
7
14
7
OUT_B
Circuit 3
Amplifier B output
1, 2, 8, 9, 10, 16
8, 9
NC
10
OUT_C
Circuit 3
Amplifier C output
11
IN-_C
Circuit 1
Amplifier C inverting input
12
IN+_C
Circuit 1
Amplifier B non-inverting input
1, 5, 8
15
No internal connection
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Pin Descriptions (Continued)
ISL28176
ISL28276
(8 LD SOIC) (8 LD SOIC)
4
ISL28276
(16 LD QSOP)
4
ISL28476
PIN
EQUIVALENT
(16 LD QSOP) NAME
CIRCUIT
7
13
V-
Circuit 4
Negative power supply
14
IN+_D
Circuit 1
Amplifier D non-inverting input
15
IN-_D
Circuit 1
Amplifier D inverting input
16
OUT_D
Circuit 3
Amplifier D output
6
EN_A
Circuit 2
Amplifier A enable pin internal pull-down; Logic “1”
selects the disabled state; Logic “0” selects the enabled
state.
11
EN_B
Circuit 2
Amplifier B enable pin with internal pull-down; Logic “1”
selects the disabled state; Logic “0” selects the enabled
state.
V+
V+
IN-
IN+
V+
LOGIC
PIN
CIRCUIT 1
V+
CAPACITIVELY
COUPLED
ESD CLAMP
OUT
V-
V-
VCIRCUIT 2
Applications Information
Introduction
The ISL28176, ISL28276 and ISL28476 are single, dual and
quad BiCMOS rail-to-rail input, output (RRIO) micropower
precision operational amplifiers. These devices are designed
to operate from a single supply (2.4V to 5.0V) or dual
supplies (±1.2V to ±2.5V) while drawing only 120µA
(ISL28276) of supply current. This combination of low power
and precision performance makes these devices suitable for
solar and battery power applications.
Rail-to-Rail Input
Many rail-to-rail input stages use two differential input pairs, a
long-tail PNP (or PFET) and an NPN (or NFET). Severe
penalties have to be paid for this circuit topology. As the input
signal moves from one supply rail to another, the operational
amplifier switches from one input pair to the other causing
drastic changes in input offset voltage and an undesired
change in magnitude and polarity of input offset current.
The devices achieve rail-to-rail input without sacrificing
important precision specifications and degrading distortion
performance. The devices’ input offset voltage exhibits a
smooth behavior throughout the entire common-mode input
range. The input bias current versus the common-mode
voltage range gives us an undistorted behavior from typically
down to the negative rail to 10% higher than the V+ rail (0.5V
higher than V+ when V+ equals 5V).
16
DESCRIPTION
VCIRCUIT 3
CIRCUIT 4
Input Protection
All input terminals have internal ESD protection diodes to the
positive and negative supply rails, limiting the input voltage
to within one diode beyond the supply rails. Both parts have
additional back-to-back diodes across the input terminals. If
overdriving the inputs is necessary, the external input current
must never exceed 5mA. External series resistors may be
used as an external protection to limit excessive external
voltage and current from damaging the inputs.
Input Bias Current Compensation
The devices contain an input bias cancellation circuit which
reduces the bias currents down to a typical of 500pA while
maintaining an excellent bandwidth for a micro-power
operational amplifier. The input stage transistors are still
biased with adequate current for speed but the canceling
circuit sinks most of the base current, leaving a small fraction
as input bias current.
Rail-to-Rail Output
A pair of complementary MOSFET devices are used to
achieve the rail-to-rail output swing. The NMOS sinks
current to swing the output in the negative direction. The
PMOS sources current to swing the output in the positive
direction. Both parts, with a 100kΩ load, will typically swing to
within 4mV of the positive supply rail and within 3mV of the
negative supply rail.
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Enable/Disable Feature
The ISL28276 (QSOP package only) offers two EN pins
(EN_A and EN_B) which disable the op amp when pulled up
to at least 2.0V. In the disabled state (output in a high
impedance state), the part consumes typically 4µA. By
disabling the part, multiple parts can be connected together
as a MUX. The outputs are tied together in parallel and a
channel can be selected by the EN pins. The loading effects
of the feedback resistors of the disabled amplifier must be
considered when multiple amplifier outputs are connected
together. The EN pin also has an internal pull-down. If left
open, the EN pin will pull to the negative rail and the device
will be enabled by default.
Using Only One Channel
The ISL28276 and ISL28476 are dual and quad channel
op amps. If the application only requires one channel when
using the ISL28276 or less than 4 channels when using the
ISL28476, the user must configure the unused channel(s) to
prevent them from oscillating. The unused channel(s) 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 channel being used. 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 59).
HIGH IMPEDANCE INPUT
V+
IN
FIGURE 60. GUARD RING EXAMPLE FOR UNITY GAIN
AMPLIFIER
Current Limiting
The ISL28176, ISL28276 and ISL28476 have 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.
Power Dissipation
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 as follows:
T JMAX = T MAX + ( θ JA xPD MAXTOTAL )
(EQ. 1)
1/2 ISL28276
1/4 ISL28476
+
FIGURE 59. 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 60 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.
17
where:
• PDMAXTOTAL is the sum of the maximum power
dissipation of each amplifier in the package (PDMAX)
• PDMAX for each amplifier can be calculated as follows:
V OUTMAX
PD MAX = 2*V S × I SMAX + ( V S - V OUTMAX ) × ---------------------------R
(EQ. 2)
L
where:
• TMAX = Maximum ambient temperature
• θJA = 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
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
Small Outline Package Family (SO)
A
D
h X 45°
(N/2)+1
N
A
PIN #1
I.D. MARK
E1
E
c
SEE DETAIL “X”
1
(N/2)
B
L1
0.010 M C A B
e
H
C
A2
GAUGE
PLANE
SEATING
PLANE
A1
0.004 C
0.010 M C A B
L
b
0.010
4° ±4°
DETAIL X
MDP0027
SMALL OUTLINE PACKAGE FAMILY (SO)
INCHES
SYMBOL
SO-14
SO16 (0.300”)
(SOL-16)
SO20
(SOL-20)
SO24
(SOL-24)
SO28
(SOL-28)
TOLERANCE
NOTES
A
0.068
0.068
0.068
0.104
0.104
0.104
0.104
MAX
-
A1
0.006
0.006
0.006
0.007
0.007
0.007
0.007
±0.003
-
A2
0.057
0.057
0.057
0.092
0.092
0.092
0.092
±0.002
-
b
0.017
0.017
0.017
0.017
0.017
0.017
0.017
±0.003
-
c
0.009
0.009
0.009
0.011
0.011
0.011
0.011
±0.001
-
D
0.193
0.341
0.390
0.406
0.504
0.606
0.704
±0.004
1, 3
E
0.236
0.236
0.236
0.406
0.406
0.406
0.406
±0.008
-
E1
0.154
0.154
0.154
0.295
0.295
0.295
0.295
±0.004
2, 3
e
0.050
0.050
0.050
0.050
0.050
0.050
0.050
Basic
-
L
0.025
0.025
0.025
0.030
0.030
0.030
0.030
±0.009
-
L1
0.041
0.041
0.041
0.056
0.056
0.056
0.056
Basic
-
h
0.013
0.013
0.013
0.020
0.020
0.020
0.020
Reference
-
16
20
24
28
Reference
-
N
SO-8
SO16
(0.150”)
8
14
16
Rev. M 2/07
NOTES:
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.
3. Dimensions “D” and “E1” are measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994
18
FN6301.4
June 23, 2009
ISL28176, ISL28276, ISL28476
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)
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
-
B
0.010
C A B
e
H
C
SEATING
PLANE
0.007
0.004 C
b
C A B
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
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19
FN6301.4
June 23, 2009