LT1490/LT1491
Dual and Quad
Micropower Rail-to-Rail
Input and Output Op Amps
FEATURES
s
s
s
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Rail-to-Rail Input and Output
Single Supply Input Range: – 0.4V to 44V
Micropower: 50µA/Amplifier Max
µ
MSOP Package
Specified on 3V, 5V and
±15V
Supplies
High Output Current: 20mA
Output Drives 10,000pF with Output Compensation
Reverse Battery Protection to 18V
No Supply Sequencing Problems
High Voltage Gain: 1500V/mV
High CMRR: 98dB
No Phase Reversal
Gain Bandwidth Product: 200kHz
APPLICATIO S
s
s
s
s
s
Battery- or Solar-Powered Systems
Portable Instrumentation
Sensor Conditioning
Supply Current Sensing
Battery Monitoring
Micropower Active Filters
4mA to 20mA Transmitters
, LTC and LT are registered trademarks of Linear Technology Corporation.
The dual LT
®
1490 and quad LT1491 op amps operate on all
single and split supplies with a total voltage of 2V to 44V
drawing only 40µA of quiescent current per amplifier. These
amplifiers are reverse supply protected; they draw no current
for reverse supply up to 18V. The input range of the LT1490/
LT1491 includes both supplies and the output swings to both
supplies. Unlike most micropower op amps, the LT1490/
LT1491 can drive heavy loads; their rail-to-rail outputs drive
20mA. The LT1490/LT1491 are unity-gain stable and drive all
capacitive loads up to 10,000pF when optional 0.22µF and
150Ω compensation is used.
The LT1490/LT1491 have a unique input stage that oper-
ates and remains high impedance when above the positive
supply. The inputs take 44V both differential and common
mode even when operating on a 3V supply. Built-in resis-
tors protect the inputs for faults below the negative supply
up to 22V. There is no phase reversal of the output for inputs
22V below V
–
or 44V above V
–
, independent of V
+
.
The LT1490 dual op amp is available in the 8-pin MSOP,
SO and PDIP packages. The quad LT1491 is available in
the 14-pin SO and PDIP packages.
For new designs it is recommended that the LT1490A/
LT1491A be used instead of the LT1490/LT1491. See the
LT1490A/LT1491A data sheet for details.
TYPICAL APPLICATIO
CHARGER
VOLTAGE
Battery Monitor
R
S
0.2Ω
I
BATT
RA
2k
R
A
'
2k
+
–
A
1/4 LT1491
Q1
2N3904
–
C
1/4 LT1491
+
R
B
2k
R
B
'
2k
LOAD
+
–
Q2
2N3904
B
1/4 LT1491
LOGIC HIGH (5V) = CHARGING
LOGIC LOW (0V) = DISCHARGING
+
V
BATT
= 12V
S1
R
G
10k
10k
D
1/4 LT1491
+
–
90.9k
I
BATT
=
V
V
OUT
=
OUT
AMPS
(R
S
)(R
G
/R
A
)(GAIN) GAIN
S1 = OPEN, GAIN = 1
S1 = CLOSED, GAIN = 10
R
A
= R
B
V
S
= 5V, 0V
U
LOGIC
V
OUT
1490/91 TA01
U
U
1
LT1490/LT1491
ABSOLUTE
AXI U
RATI GS
(Note 1)
Junction Temperature ........................................... 150°C
Specified Temperature Range (Note 3) .. – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
Total Supply Voltage (V
+
to V
–
) .............................. 44V
Input Differential Voltage ......................................... 44V
Input Current ......................................................
±25mA
Output Short-Circuit Duration (Note 2) .........Continuous
Operating Temperature Range ................ – 40°C to 85°C
PACKAGE/ORDER INFORMATION
(For new designs, use the LT1490A or LT1491A)
TOP VIEW
OUT A
–IN A
+IN A
V
–
1
2
A
3
B
4
5
+IN B
6
–IN B
8
7
V
+
OUT B
ORDER PART
NUMBER
LT1490CMS8
LT1490CN8
LT1490CS8
LT1490IN8
LT1490IS8
MS8 PART MARKING
LTBB
S8 PART MARKING
1490 1490I
OUT A
–IN A
+IN A
V
+
+IN B
–IN B
OUT B
1
2
3
4
5
6
7
MS8 PACKAGE
N8 PACKAGE
8-LEAD MSOP
8-LEAD PDIP
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 250°C/ W (MS8)
T
JMAX
= 150°C,
θ
JA
= 130°C/ W (N8)
T
JMAX
= 150°C,
θ
JA
= 190°C/ W (S8)
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
The
q
denotes specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
S
= 3V, 0V; V
S
= 5V, 0V; V
CM
= V
OUT
= half supply, unless otherwise noted. (Note 3)
CONDITIONS
LT1490 N Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
LT1490 S Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
LT1491 N Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
LT1490CMS8 Package, LT1491 S Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
MIN
q
q
V
OS
TC
I
OS
I
B
Input Offset Voltage Drift
Input Offset Current
0°C
≤
T
A
≤
70°C (Note 7)
–40°C
≤
T
A
≤
85°C (Note 7)
V
CM
= 44V (Note 4)
Input Bias Current
V
CM
= 44V (Note 4)
V
S
= 0V
0.1Hz to 10Hz
Input Noise Voltage
2
U
U
W
W W
U
W
TOP VIEW
14 OUT D
A
D
13 –IN D
12 +IN D
11 V
–
10 +IN C
B
C
9
8
– IN C
OUT C
ORDER PART
NUMBER
LT1491CN
LT1491CS
LT1491IN
LT1491IS
N PACKAGE
S PACKAGE
14-LEAD PDIP 14-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 110°C/ W (N)
T
JMAX
= 150°C,
θ
JA
= 150°C/ W (S)
TYP
220
MAX
800
1000
1100
950
1200
1300
1100
1350
1450
1450
1650
1750
4
4
0.8
0.8
8
10
UNITS
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV/°C
µV/°C
nA
µA
nA
µA
nA
µV
P-P
220
q
q
300
q
q
350
q
q
q
q
q
q
q
q
2
2
0.2
4
4
0.1
1
LT1490/LT1491
ELECTRICAL CHARACTERISTICS
SYMBOL
e
n
i
n
R
IN
C
IN
CMRR
A
VOL
PARAMETER
Input Noise Voltage Density
Input Noise Current Density
Input Resistance
Input Capacitance
Input Voltage Range
Common Mode Rejection Ratio
(Note 4)
Large-Signal Voltage Gain
V
CM
= 0V to V
CC
– 1V
V
CM
= 0V to 44V
V
S
= 3V, V
O
= 500mV to 2.5V, R
L
= 10k
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
V
S
= 5V, V
O
= 500mV to 4.5V, R
L
= 10k
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
V
S
= 3V, No Load
V
S
= 3V, I
SINK
= 5mA
V
S
= 5V, No Load
V
S
= 5V, I
SINK
= 5mA
V
S
= 5V, I
SINK
= 10mA
V
S
= 3V, No Load
V
S
= 3V, I
SOURCE
= 5mA
V
S
= 5V, No Load
V
S
= 5V, I
SOURCE
= 10mA
V
S
= 3V, Short to GND
V
S
= 3V, Short to V
CC
V
S
= 5V, Short to GND
V
S
= 5V, Short to V
CC
PSRR
Power Supply Rejection Ratio
Minimum Operating Supply Voltage
Reverse Supply Voltage
Supply Current per Amplifier
(Note 5)
Gain Bandwidth Product
(Note 4)
Slew Rate
(Note 6)
V
S
= 2.5V to 12.5V, V
CM
= V
O
= 1V
I
S
= – 100µA per Amplifier
q
q
q
q
The
q
denotes specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
S
= 3V, 0V; V
S
= 5V, 0V; V
CM
= V
OUT
= half supply, unless otherwise noted. (Note 3)
CONDITIONS
f = 1kHz
f = 1kHz
Differential
Common Mode, V
CM
= 0V to 44V
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
TYP
50
0.03
MAX
UNITS
nV/√Hz
pA/√Hz
MΩ
MΩ
6
4
0
84
80
200
133
100
400
250
200
17
11
4.6
44
98
98
1500
pF
V
dB
dB
V/mV
V/mV
V/mV
V/mV
V/mV
V/mV
1500
V
OL
Output Voltage Swing Low
22
250
22
250
330
2.978
2.6
4.978
4.6
15
30
25
30
98
2
27
40
180
50
450
50
500
500
mV
mV
mV
mV
mV
V
V
V
V
mA
mA
mA
mA
V
OH
Output Voltage Swing High
2.95
2.55
4.95
4.30
10
10
15
15
84
18
I
SC
Short-Circuit Current (Note 2)
2.5
50
55
dB
V
V
µA
µA
kHz
kHz
kHz
V/µs
V/µs
V/µs
I
S
GBW
f = 1kHz
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
A
V
= – 1, R
L
=
∞
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
q
q
q
q
110
100
90
0.035
0.031
0.030
SR
0.06
3
LT1490/LT1491
ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
The
q
denotes specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
S
=
±15V,
V
CM
= 0V, V
OUT
= 0V, unless otherwise noted. (Note 3)
CONDITIONS
LT1490 N, S Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
LT1491 N Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
LT1490CMS8 Package, LT1491 S Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
q
q
MIN
TYP
250
MAX
1200
1400
1500
1250
1500
1600
1600
1850
1950
6
6
0.8
8
UNITS
µV
µV
µV
µV
µV
µV
µV
µV
µV
µV/°C
µV/°C
nA
nA
µV
P-P
nV/√Hz
pA/√Hz
MΩ
MΩ
pF
350
q
q
400
q
q
q
q
q
q
V
OS
TC
I
OS
I
B
e
n
i
n
R
IN
C
IN
CMRR
A
VOL
Input Offset Voltage Drift
Input Offset Current
Input Bias Current
Input Noise Voltage
Input Noise Voltage Density
Input Noise Current Density
Input Resistance
Input Capacitance
Input Voltage Range
Common Mode Rejection Ratio
Large-Signal Voltage Gain
0°C
≤
T
A
≤
70°C (Note 7)
– 40°C
≤
T
A
≤
85°C (Note 7)
3
3
0.2
4
1
50
0.03
6
17
15000
4.6
0.1Hz to 10Hz
f = 1kHz
f = 1kHz
Differential
Common Mode, V
CM
= – 15V to 14V
q
– 15
80
100
75
50
±14.9
±14.5
±14.5
±20
±15
±10
88
98
250
29
V
dB
V/mV
V/mV
V/mV
V
V
V
mA
mA
mA
dB
V
CM
= – 15V to 29V
V
O
=
±14V,
R
L
= 10k
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
No Load
I
OUT
=
±5mA
I
OUT
=
±10mA
Short to GND
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
V
S
=
±1.25V
to
±22V
q
q
q
q
q
V
O
Output Voltage Swing
±14.978
±14.750
±14.670
±25
I
SC
Short-Circuit Current (Note 2)
q
q
q
q
PSRR
I
S
GBW
Power Supply Rejection Ratio
Supply Current per Amplifier
Gain Bandwidth Product
98
50
70
85
µA
µA
kHz
kHz
kHz
V/µs
V/µs
V/µs
f = 1kHz
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
A
V
= – 1, R
L
=
∞,
V
O
=
±10V,
Measure at V
O
=
±5V
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
q
q
125
110
100
0.0375
200
SR
Slew Rate
0.07
q
q
0.0330
0.0300
Note 1:
Absolute Maximum Ratings are those values beyond which the
life of the device may be impaired.
Note 2:
A heat sink may be required to keep the junction temperature
below absolute maximum. This depends on the power supply voltage
and how many amplifiers are shorted.
Note 3:
The LT1490C/LT1491C are guaranteed to meet specified
performance from 0°C to 70°C. The LT1490C/LT1491C are designed,
characterized and expected to meet specified performance from – 40°C
to 85°C but are not tested or QA sampled at these temperatures.
The LT1490I/LT1491I are guaranteed to meet specified performance from
– 40°C to 85°C.
Note 4:
V
S
= 5V limits are guaranteed by correlation to V
S
= 3V and
V
S
=
±15V
tests.
Note 5:
V
S
= 3V limits are guaranteed by correlation to V
S
= 5V and
V
S
=
±15V
tests.
Note 6:
Guaranteed by correlation to slew rate at V
S
=
±15V
and GBW
at V
S
= 3V and V
S
=
±15V
tests.
Note 7:
This parameter is not 100% tested.
4
LT1490/LT1491
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Supply Voltage
80
CHANGE IN INPUT OFFSET VOLTAGE (µV)
SUPPLY CURRENT PER AMPLIFIER (µA)
70
60
50
40
30
20
10
0
0
5
10 15 20 25 30 35 40
TOTAL SUPPLY VOLTAGE (V)
45
T
A
= 125°C
T
A
= 25°C
200
100
0
–100
–200
–300
T
A
= 125°C
0
1
3
4
2
TOTAL SUPPLY VOLTAGE (V)
5
1490/91 G02
INPUT BIAS CURRENT (nA)
T
A
= –55°C
Output Saturation Voltage
vs Load Current (Output High)
1
OUTPUT SATURATION VOLTAGE (V)
OUTPUT SATURATION VOLTAGE (V)
V
S
=
±
2.5V
V
OD
= 30mV
1
OUTPUT SATURATION VOLTAGE (mV)
T
A
= 125°C
0.1
T
A
= 25°C
T
A
= – 55°C
0.01
0.001
0.01
0.1
1
SOURCING LOAD CURRENT (mA)
0.1Hz to 10Hz Noise Voltage
INPUT NOISE VOLTAGE DENSITY (nV/√Hz)
V
S
=
±2.5V
NOISE VOLTAGE (400nV/DIV)
80
INPUT NOISE CURRENT DENSITY (pA/√Hz)
0
1
2
3
4 5 6
TIME (SEC)
7
U W
1490/91 G01
1490/90 G04
Minimum Supply Voltage
400
300
6000
4000
2000
Input Bias Current
vs Common Mode Voltage
V
S
= 5V, 0V
T
A
= 25°C
T
A
= –55°C
30
20
10
0
–10
4.0
T
A
= –55°C
T
A
= 25°C
T
A
= 125°C
4.4
5.2
5.6
4.8
COMMON MODE VOLTAGE (V)
44
1490/91 G03
– 400
Output Saturation Voltage
vs Load Current (Output Low)
V
S
=
±
2.5V
V
OD
= 30mV
100
90
80
70
60
50
40
30
20
10
0
Output Saturation Voltage
vs Input Overdrive
V
S
=
±
2.5V
NO LOAD
T
A
= 125°C
0.1
T
A
= 25°C
T
A
= – 55°C
OUTPUT HIGH
OUTPUT LOW
0
10 20 30 40 50 60 70 80 90 100
INPUT OVERDRIVE (mV)
1490/91 G06
10
0.01
0.001
0.01
0.1
1
SINKING LOAD CURRENT (mA)
10
1490/90 G05
Noise Voltage Density
vs Frequency
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
Input Noise Current vs Frequency
70
60
50
40
30
8
9
10
1
10
100
FREQUENCY (Hz)
1k
1490/91 G08
1
10
100
FREQUENCY (Hz)
1k
1490/91 G09
1490 G07
5
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