DATASHEET
ISL28176, ISL28276, ISL28476
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.
Features
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.
• 500pA typical input bias current
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.
• Single supply operation down to 2.4V
Ordering Information
Applications
PART NUMBER
(Note)
PART
MARKING
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
*Add “-T7” suffix for tape and reel. Please refer to TB347 for details
on reel specifications.
FN6301
Rev 4.00
June 23, 2009
• Low power 120µA typical supply current (ISL28276)
• 100µV maximum offset voltage
• 400kHz typical gain-bandwidth product
• 115dB typical PSRR and CMRR
• Input is capable of swinging above V+ and to V- (ground
sensing)
• Rail-to-rail input and output (RRIO)
• Pb-free (RoHS compliant)
• Battery- or solar-powered systems
• 4mA to 25mA current loops
• Handheld consumer products
• Medical devices
• Thermocouple amplifiers
• Photodiode pre-amps
• pH probe amplifiers
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.
FN6301 Rev 4.00
June 23, 2009
Page 1 of 19
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
FN6301 Rev 4.00
June 23, 2009
+
-
IN-_B 6
12 IN+_C
+
-
IN+_B 5
11 IN-_C
10 OUT_C
9 NC
Page 2 of 19
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)
JA (°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. 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
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
V OS
--------------T
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
FN6301 Rev 4.00
June 23, 2009
Page 3 of 19
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 = 100k
350
350
550
V/mV
ISL28176,
VO = 0.5V to 4.5V, RL = 1k
25
V/mV
ISL28276, ISL28476
VO = 0.5V to 4.5V, RL = 1k
95
V/mV
Output low, RL = 100k
3
8
10
mV
130
200
300
mV
Output high, RL = 100k
4.994
4.992
4.997
V
Output high, RL = 1k
4.750
4.7
4.867
V
Output low, RL = 100k
Output low, RL = 1k
IS,ON
MAX
(Note 2)
ISL28176
VO = 0.5V to 4.5V, RL = 100k
Output low, RL = 1k
Maximum Output Voltage Swing
ISL28276, ISL28476
TYP
3
6
30
mV
130
175
225
mV
Output high, RL = 100k
4.990
4.97
4.996
V
Output high, RL = 1k
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 = 10
18
18
31
mA
ISL28276, ISL28476
RL = 10
29
23
31
mA
ISL28176
RL = 10
17
15
26
mA
ISL28276, ISL28476
RL = 10
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)
FN6301 Rev 4.00
June 23, 2009
5
2
V
V
0.7
0.8
V
1.3
1.5
µA
Page 4 of 19
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 = 100kRG = 1k
RL = 10kto 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 = 10kto VCM
78
dB
PSRR+ @ 120Hz
Power Supply Rejection Ratio, +V
ISL28176
V+, V- = ±1.2V and ±2.5V,
VSOURCE = 1VP-P, RL = 10kto VCM
90
dB
ISL28276, ISL28476
V+, V- = ±1.2V and ±2.5V,
VSOURCE = 1VP-P, RL = 10kto VCM
105
dB
ISL28176
V+, V- = ±1.2V and ±2.5V
VSOURCE = 1VP-P, RL = 10kto VCM
70
dB
ISL28276, ISL28476
V+, V- = ±1.2V and ±2.5V
VSOURCE = 1VP-P, RL = 10kto 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 = 1kto 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.
FN6301 Rev 4.00
June 23, 2009
Page 5 of 19
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 = 221k
RG = 2.23k
15
10
5
0
100
1k
25
20
15
V+ = 2V
10
5
10k
FREQUENCY (Hz)
100k
V+, V- = ±1.25V
AV = 100
V+, V- = ±2.5V
RL = 10k
CL = 2.7pF
RF/RG = 99.02
V+, V- = ±1.0V
RF = 221k
RG = 2.23k
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
PHASE
-40
-80
1
10
100
-80
1k
10k
100k
1M
-120
10M
FREQUENCY (Hz)
FIGURE 5. AVOL vs FREQUENCY @ 100k LOAD
FN6301 Rev 4.00
June 23, 2009
GAIN (dB)
40
PHASE (°)
GAIN (dB)
PHASE
100
60
50
40
0
20
GAIN
-50
0
-20
10
-100
100
1k
10k
100k
-150
1M
FREQUENCY (Hz)
FIGURE 6. AVOL vs FREQUENCY @ 1k LOAD
Page 6 of 19
PHASE (°)
GAIN (dB)
-1
V+, V- = ±1.2V
RL = 1k
V+, V- = ±2.5V
RL = 1k
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 = 100k
AV = +1
90
60
50
40
V+, V- = ±2.5V
VSOURCE = 1VP-P
RL = 100k
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 (nVHz)
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)
10k
100k
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 (pAHz)
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
FN6301 Rev 4.00
June 23, 2009
1.0
0.1
1
10
100
1k
FREQUENCY (Hz)
10k
100k
FIGURE 12. ISL28276, ISL28476 CURRENT NOISE vs
FREQUENCY
Page 7 of 19
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
3
0
50
100
150
200
250
TIME (µs)
300
350
6
7
8
9
10
VOUT
2.50
2.48
2.42
400
V+ = 5VDC
VOUT = 0.1VP-P
RL = 500
AV = +1
0
2
4
6
8
10
12
14
16
18
20
TIME (µs)
FIGURE 16. ISL28276, ISL28476 SMALL SIGNAL TRANSIENT
RESPONSE
2.5
4.0
VIN
2.0
VOUT
3.5
1.5
1.0
0.5
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
VOLTS (V)
LARGE SIGNAL (V)
5
VIN
2.44
FIGURE 15. ISL28176 SMALL SIGNAL TRANSIENT RESPONSE
0
50
100
150
200
250
TIME (µs)
3.0
2.5
VOUT
VIN
1.5
300
350
FIGURE 17. ISL28176 LARGE SIGNAL TRANSIENT
RESPONSE
FN6301 Rev 4.00
June 23, 2009
V+ = 5VDC
VOUT = 2VP-P
RL = 1k
AV = -1
2.0
-2.0
-2.5
4
2.46
0
-2
2
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
400
1.0
0
20
40
60
TIME (µs)
80
100
FIGURE 18. ISL28276, ISL28476 LARGE SIGNAL TRANSIENT
RESPONSE
Page 8 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
100
AV = -1
VIN = 200mVP-P
V+ = 5V
V- = 0V
80
60
40
VOS (V)
1V/DIV
EN
INPUT
0
0.1V/DIV
0
-20
-40
VOUT
V+ = 5V
RL = OPEN
RF = 100k, RG = 100
AV = +1000
-60
-80
0
-100
10µs/DIV
FIGURE 19. ISL28276 ENABLE TO OUTPUT DELAY TIME
40
20
0
-20
-80
-100
-1
V+ = 5V
RL = OPEN
RF = 100k, RG = 100
AV = +1000
0
1
2
3
VCM (V)
4
5
4
5
6
95
75
55
35
2.0
2.5
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.0
5.5
FIGURE 22. ISL28276 SUPPLY CURRENT vs SUPPLY VOLTAGE
75
150
n = 12
N=7
70
100
65
50
CURRENT (µA)
SUPPLY CURRENT (µA)
2
3
VCM (V)
115
6
FIGURE 21. INPUT OFFSET CURRENT vs COMMON-MODE
INPUT VOLTAGE
MAX
60
MIN
55
MEDIAN
50
45
-40
1
135
SUPPLY CURRENT (µA)
60
-60
0
155
80
-40
-1
FIGURE 20. INPUT OFFSET VOLTAGE vs COMMON-MODE
INPUT VOLTAGE
100
I-BIAS (nA)
20
MAX
0
MEDIAN
-50
MIN
-100
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 23. ISL28176 SUPPLY CURRENT vs TEMPERATURE
VS = ±2.5V ENABLED, RL = INF
FN6301 Rev 4.00
June 23, 2009
-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
Page 9 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
4.9
N = 1000
CURRENT (µA)
N=7
4.7
300
MAX
280
MEDIAN
260
4.5
CURRENT (µA)
320
(Continued)
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
200
100
120
SO PACKAGE
n = 12
150
MAX
VOS (µV)
VOS (µV)
20
40
60
80
TEMPERATURE (°C)
200
150
100
0
FIGURE 26. ISL28276 SUPPLY CURRENT vs TEMPERATURE,
V+, V- = ±2.5V DISABLED, RL = INF
SO PACKAGE
n = 12
-20
MEDIAN
50
100
MAX
MEDIAN
50
MIN
0
0
MIN
-50
-40
-20
0
20
40
60
80
100
-50
-40
120
-20
0
FIGURE 27. ISL28176 INPUT OFFSET VOLTAGE vs
TEMPERATURE VS = ±2.5V
150
150
N=7
60
80
100
120
N=7
100
MAX
50
MAX
50
VOS (µV)
VOS (µV)
40
FIGURE 28. ISL28176 INPUT OFFSET VOLTAGE vs
TEMPERATURE VS = ±1.2V
100
MEDIAN
0
-50
MEDIAN
0
-50
MIN
MIN
-100
-150
-40
20
TEMPERATURE (°C)
TEMPERATURE (°C)
-20
0
20
-100
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 29. ISL28276 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±2.5V
FN6301 Rev 4.00
June 23, 2009
-150
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 30. ISL28276 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±1.2V
Page 10 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
200
(Continued)
200
N = 1000
150
100
MAX
50
VOS (µV)
VOS (µV)
100
MEDIAN
0
-50
MIN
-100
-20
0
20
40
60
80
TEMPERATURE (°C)
100
-50
-200
-40
120
MIN
-20
0
n = 12
CURRENT (nA)
1.5
MAX
1.0
0.5
MEDIAN
0
-20
0
2.0
1.5
MAX
1.0
MEDIAN
0.5
0
MIN
20
40
60
80
100
-0.5
-40
120
MIN
-20
0
TEMPERATURE (°C)
3.0
2.5
MAX
IBIAS+ (nA)
MEDIAN
0.5
0
MIN
-0.5
60
80
100
120
N = 1000
2.0
1.5
1.0
40
FIGURE 34. ISL28176 IBIAS (+) vs TEMPERATURE VS = ±1.2V
N = 1000
2.0
20
TEMPERATURE (°C)
FIGURE 33. ISL28176 IBIAS (+) vs TEMPERATURE VS = ±2.5V
IBIAS+ (nA)
120
2.5
2.0
MAX
1.5
1.0
MEDIAN
0.5
0
MIN
-0.5
-1.0
-1.5
-40
100
3.0
n = 12
2.5
20
40
60
80
TEMPERATURE (°C)
FIGURE 32. ISL28476 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±1.2V
2.5
CURRENT (nA)
MEDIAN
0
-150
FIGURE 31. ISL28476 VOS vs TEMPERATURE, VIN = 0V,
V+,V- = ±2.5V
-0.5
-40
MAX
50
-100
-150
-200
-40
N = 1000
150
-1.0
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 35. ISL28276 ISL28476 IBIAS (+) vs TEMPERATURE,
V+,V- = ±2.5V
FN6301 Rev 4.00
June 23, 2009
-1.5
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 36. ISL28276, ISL28476 IBIAS (+) vs TEMPERATURE,
V+,V- = ±1.2V
Page 11 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
2.5
3.0
n = 12
2.5
1.5
MAX
CURRENT (nA)
CURRENT (nA)
2.0
1.0
MEDIAN
0.5
0
-0.5
-40
0
20
2.0
MAX
1.5
1.0
MEDIAN
0.5
0
MIN
-20
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
2.0
2.5
N = 1000
1.0
MEDIAN
0.5
0
MIN
-0.5
80
100
120
MAX
0
-0.5
-1.0
-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)
60
1.5
IBIAS- (nA)
IBIAS- (nA)
N = 1000
2.0
MAX
1.0
1.0
0.5
0.5
MEDIAN
0
-0.5
MEDIAN
-1.0
0
-0.5
-40
40
FIGURE 38. ISL28176 IBIAS (-) vs TEMPERATURE VS = ±1.2V
1.5
-2.0
-40
20
TEMPERATURE (°C)
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
100
FIGURE 41. ISL28176 INPUT OFFSET CURRENT vs
TEMPERATURE, VS = ±2.5V
FN6301 Rev 4.00
June 23, 2009
MIN
-1.5
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
Page 12 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
900
800
(Continued)
1050
n = 12
N = 1000
MAX
MAX
950
600
500
850
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
CMRR (dB)
CMRR (dB)
125
MAX
115
110
105
MEDIAN
MEDIAN
115
110
105
MIN
100
100
95
-40
120
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
135
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
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
FN6301 Rev 4.00
June 23, 2009
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
Page 13 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
4.91
(Continued)
4.91
n = 12
4.90
MAX
4.89
MAX
MEDIAN
VOUT (V)
VOUT (V)
4.88
4.87
4.86
4.85
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
100
MIN
0
220
160
200
150
MEDIAN
MAX
180
160
140
MIN
100
0
20
40
60
80
100
90
-40
120
MAX
-20
0
N = 1000
37
MAX
33
MEDIAN
MIN
29
27
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
FN6301 Rev 4.00
June 23, 2009
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
31
20
TEMPERATURE (°C)
TEMPERATURE (°C)
35
MEDIAN
MIN
120
100
-20
120
130
110
25
-40
100
N = 1000
140
120
39
20
40
60
80
TEMPERATURE (°C)
170
n = 12
-20
-20
FIGURE 50. ISL28276, ISL28476 VOUT HIGH vs
TEMPERATURE, V+,V- = ±2.5V, RL= 1k
VOUT (mV)
VOUT (mV)
4.85
-40
120
FIGURE 49. ISL28176 VOUT HIGH vs TEMPERATURE,
V+, V- = ±2.5V, RL= 1k
80
-40
MEDIAN
4.88
4.86
4.83
240
4.89
4.87
4.84
4.82
-40
N = 1000
4.90
-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
Page 14 of 19
ISL28176, ISL28276, ISL28476
Typical Performance Curves
(Continued)
0.24
0.23
n = 12
N = 1000
0.22
0.19
+ SLEW RATE (V/s)
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
0.24
n = 12
MAX
- SLEW RATE (V/s)
CURRENT (pA)
120
N = 1000
0.22
0.15
0.14
MEDIAN
0.13
MIN
0.12
0.11
0.10
-40
100
FIGURE 56. ISL28276, ISL28476 + SLEW RATE vs
TEMPERATURE, VOUT = ±1.5V, AV = +2
0.17
0.16
20
40
60
80
TEMPERATURE (°C)
0.20
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
FN6301 Rev 4.00
June 23, 2009
No internal connection
Page 15 of 19
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+
CIRCUIT 1
V+
LOGIC
PIN
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).
FN6301 Rev 4.00
June 23, 2009
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 100k load, will typically swing to within 4mV of the positive
supply rail and within 3mV of the negative supply rail.
Page 16 of 19
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).
+
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.
FN6301 Rev 4.00
June 23, 2009
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 + JA xPD MAXTOTAL
(EQ. 1)
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
• 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 19
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
NOTES:
Rev. M 2/07
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
FN6301 Rev 4.00
June 23, 2009
Page 18 of 19
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)
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
FN6301 Rev 4.00
June 23, 2009
Page 19 of 19