www.docs.chipfind.ru
1
LT1490/LT1491
Dual and Quad
Micropower Rail-to-Rail
Input and Output Op Amps
FEATURES
DESCRIPTIO
N
U
s
Rail-to-Rail Input and Output
s
Single Supply Input Range: 0.4V to 44V
s
Micropower: 50
A/Amplifier Max
s
Specified on 3V, 5V and
15V Supplies
s
High Output Current: 20mA
s
Output Drives 10,000pF with Output Compensation
s
Reverse Battery Protection to 18V
s
No Supply Sequencing Problems
s
High Voltage Gain: 1500V/mV
s
High CMRR: 98dB
s
No Phase Reversal
s
Gain Bandwidth Product: 200kHz
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 40
A 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 0.22
F and
150
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 SO and
PDIP packages. The quad LT1491 is available in the 14-pin
SO and PDIP packages.
s
Battery- or Solar-Powered Systems
Portable Instrumentation
Sensor Conditioning
s
Supply Current Sensing
s
Battery Monitoring
s
Micropower Active Filters
s
4mA to 20mA Transmitters
APPLICATIO
N
S
U
+
+
RA
2k
Q2
2N3904
S1
S1 = OPEN, GAIN = 1
S1 = CLOSED, GAIN = 10
R
A
= R
B
V
S
= 5V, 0V
10k
90.9k
V
OUT
LOGIC
1490/91 TA01
LOGIC HIGH (5V) = CHARGING
LOGIC LOW (0V) = DISCHARGING
R
G
10k
Q1
2N3904
R
S
0.2
CHARGER
VOLTAGE
A
1/4 LT1491
B
1/4 LT1491
R
A
'
2k
R
B
2k
V
BATT
= 12V
I
BATT
+
R
B
'
2k
LOAD
+
+
C
1/4 LT1491
D
1/4 LT1491
V
OUT
(R
S
)(R
G
/R
A
)(GAIN)
V
OUT
GAIN
I
BATT
= = AMPS
Battery Monitor
TYPICAL APPLICATIO
N
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
2
LT1490/LT1491
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
Junction Temperature ........................................... 150
C
Specified Temperature Range (Note 2) .. 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 1) ......... Continuous
Operating Temperature Range ................ 40
C to 85
C
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
ORDER PART
NUMBER
Consult factory for Industrial and Military grade parts.
LT1491CN
LT1491CS
TOP VIEW
S PACKAGE
14-LEAD PLASTIC SO
N PACKAGE
14-LEAD PDIP
1
2
3
4
5
6
7
14
13
12
11
10
9
8
A
B
C
OUT A
IN A
+IN A
V
+
+IN B
IN B
OUT B
OUT D
IN D
+IN D
V
+IN C
IN C
OUT C
D
T
JMAX
= 150
C,
JA
= 110
C/ W (N)
T
JMAX
= 150
C,
JA
= 150
C/ W (S)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage
LT1490 N Package
220
800
V
0
C
T
A
70
C
q
1000
V
40
C
T
A
85
C
q
1100
V
LT1490 S Package
220
950
V
0
C
T
A
70
C
q
1200
V
40
C
T
A
85
C
q
1300
V
LT1491 N Package
300
1100
V
0
C
T
A
70
C
q
1350
V
40
C
T
A
85
C
q
1450
V
LT1490CMS8 Package, LT1491 S Package
350
1450
V
0
C
T
A
70
C
q
1650
V
40
C
T
A
85
C
q
1750
V
Input Offset Voltage Drift
0
C
T
A
70
C (Note 6)
q
2
4
V/
C
I
OS
Input Offset Current
q
0.2
0.8
nA
V
CM
= 44V (Note 3)
q
0.8
A
I
B
Input Bias Current
q
4
8
nA
V
CM
= 44V (Note 3)
q
4
10
A
V
S
= 0V
0.1
nA
Input Noise Voltage
0.1Hz to 10Hz
1
V
P-P
e
n
Input Noise Voltage Density
f = 1kHz
50
nV/
Hz
i
n
Input Noise Current Density
f = 1kHz
0.03
pA/
Hz
ELECTRICAL CHARACTERISTICS
V
S
= 3V, 0V; V
S
= 5V, 0V; V
CM
= V
OUT
= half supply, T
A
= 25
C, unless otherwise noted. (Note 2)
T
JMAX
= 150
C,
JA
= 250
C/ W (MS8)
T
JMAX
= 150
C,
JA
= 130
C/ W (N8)
T
JMAX
= 150
C,
JA
= 190
C/ W (S8)
1
2
3
4
8
7
6
5
TOP VIEW
MS8 PACKAGE
8-LEAD MSOP
N8 PACKAGE
8-LEAD PDIP
S8 PACKAGE
8-LEAD PLASTIC SO
V
+
OUT B
IN B
+IN B
A
B
OUT A
IN A
+IN A
V
S8 PART MARKING
MS8 PART MARKING
ORDER PART
NUMBER
LTBB
1490
LT1490CMS8
LT1490CN8
LT1490CS8
3
LT1490/LT1491
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage
LT1490 N, S Package
250
1200
V
0
C
T
A
70
C
q
1400
V
40
C
T
A
85
C
q
1500
V
LT1491 N Package
350
1250
V
0
C
T
A
70
C
q
1500
V
40
C
T
A
85
C
q
1600
V
LT1490CMS8 Package, LT1491 S Package
400
1600
V
0
C
T
A
70
C
q
1850
V
40
C
T
A
85
C
q
1950
V
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
R
IN
Input Resistance
Differential
6
17
M
Common Mode, V
CM
= 0V to 44V
4
11
M
C
IN
Input Capacitance
4.6
pF
Input Voltage Range
q
0
44
V
CMRR
Common Mode Rejection Ratio
V
CM
= 0V to V
CC
1V
q
84
98
dB
(Note 3)
V
CM
= 0V to 44V
q
80
98
dB
A
VOL
Large-Signal Voltage Gain
V
S
= 3V, V
O
= 500mV to 2.5V, R
L
= 10k
200
1500
V/mV
0
C
T
A
70
C
q
133
V/mV
40
C
T
A
85
C
q
100
V/mV
V
S
= 5V, V
O
= 500mV to 4.5V, R
L
= 10k
400
1500
V/mV
0
C
T
A
70
C
q
250
V/mV
40
C
T
A
85
C
q
200
V/mV
V
OL
Output Voltage Swing Low
V
S
= 3V, No Load
q
22
50
mV
V
S
= 3V, I
SINK
= 5mA
q
250
450
mV
V
S
= 5V, No Load
q
22
50
mV
V
S
= 5V, I
SINK
= 5mA
q
250
500
mV
V
S
= 5V, I
SINK
= 10mA
330
500
mV
V
OH
Output Voltage Swing High
V
S
= 3V, No Load
q
2.95
2.978
V
V
S
= 3V, I
SOURCE
= 5mA
q
2.55
2.6
V
V
S
= 5V, No Load
q
4.95
4.978
V
V
S
= 5V, I
SOURCE
= 10mA
q
4.30
4.6
V
I
SC
Short-Circuit Current (Note 1)
V
S
= 3V, Short to GND
10
15
mA
V
S
= 3V, Short to V
CC
10
30
mA
V
S
= 5V, Short to GND
15
25
mA
V
S
= 5V, Short to V
CC
15
30
mA
PSRR
Power Supply Rejection Ratio
V
S
= 2.5V to 12.5V, V
CM
= V
O
= 1V
q
84
98
dB
Minimum Operating Supply Voltage
q
2
2.5
V
Reverse Supply Voltage
I
S
= 100
A per Amplifier
q
18
27
V
I
S
Supply Current per Amplifier
40
50
A
(Note 4)
q
55
A
GBW
Gain Bandwidth Product
f = 1kHz
110
180
kHz
(Note 3)
0
C
T
A
70
C
q
100
kHz
40
C
T
A
85
C
q
90
kHz
SR
Slew Rate
A
V
= 1, R
L
=
0.035
0.06
V/
s
(Note 5)
0
C
T
A
70
C
q
0.031
V/
s
40
C
T
A
85
C
q
0.030
V/
s
V
S
= 3V, 0V; V
S
= 5V, 0V; V
CM
= V
OUT
= half supply, T
A
= 25
C, unless otherwise noted. (Note 2)
ELECTRICAL CHARACTERISTICS
V
S
=
15V, V
CM
= 0V, V
OUT
= 0V, T
A
= 25
C, unless otherwise noted. (Note 2)
4
LT1490/LT1491
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Offset Voltage Drift
0
C
T
A
70
C (Note 6)
q
3
6
V/
C
I
OS
Input Offset Current
q
0.2
0.8
nA
I
B
Input Bias Current
q
4
8
nA
Input Noise Voltage
0.1Hz to 10Hz
1
V
P-P
e
n
Input Noise Voltage Density
f = 1kHz
50
nV/
Hz
i
n
Input Noise Current Density
f = 1kHz
0.03
pA/
Hz
R
IN
Input Resistance
Differential
6
17
M
Common Mode, V
CM
= 15V to 14V
15000
M
C
IN
Input Capacitance
4.6
pF
Input Voltage Range
q
15
29
V
CMRR
Common Mode Rejection Ratio
V
CM
= 15V to 29V
q
80
98
dB
A
VOL
Large-Signal Voltage Gain
V
O
=
14V, R
L
= 10k
100
250
V/mV
0
C
T
A
70
C
q
75
V/mV
40
C
T
A
85
C
q
50
V/mV
V
O
Output Voltage Swing
No Load
q
14.9
14.978
V
I
OUT
=
5mA
q
14.5
14.750
V
I
OUT
=
10mA
14.5
14.670
V
I
SC
Short-Circuit Current (Note 1)
Short to GND
20
25
mA
0
C
T
A
70
C
q
15
mA
40
C
T
A
85
C
q
10
mA
PSRR
Power Supply Rejection Ratio
V
S
=
1.25V to
22V
q
88
98
dB
I
S
Supply Current per Amplifier
50
70
A
q
85
A
GBW
Gain Bandwidth Product
f = 1kHz
125
200
kHz
0
C
T
A
70
C
q
110
kHz
40
C
T
A
85
C
q
100
kHz
SR
Slew Rate
A
V
= 1, R
L
=
,
V
O
=
10V,
0.0375
0.07
V/
s
Measure at V
O
=
5V
0
C
T
A
70
C
q
0.0330
V/
s
40
C
T
A
85
C
q
0.0300
V/
s
V
S
=
15V, V
CM
= 0V, V
OUT
= 0V, T
A
= 25
C, unless otherwise noted. (Note 2)
ELECTRICAL CHARACTERISTICS
The
q
denotes specifications which apply over the full operating
temperature range.
Note 1: 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 2: The LT1490/LT1491 are designed, characterized and expected
to meet these extended temperature limits, but are not tested at 40
C
and 85
C. Guaranteed I grade parts are available, consult factory.
Note 3: V
S
= 5V limits are guaranteed by correlation to V
S
= 3V and
V
S
=
15V tests.
Note 4: V
S
= 3V limits are guaranteed by correlation to V
S
= 5V and
V
S
=
15V tests.
Note 5: Guaranteed by correlation to slew rate at V
S
=
15V and GBW
at V
S
= 3V and V
S
=
15V tests.
Note 6: This parameter is not 100% tested.
5
LT1490/LT1491
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
TOTAL SUPPLY VOLTAGE (V)
0
0
SUPPLY CURRENT PER AMPLIFIER (
A)
10
30
40
50
70
10
20
25
45
1490/91 G01
20
80
60
5
15
30
35
40
T
A
= 125
C
T
A
= 25
C
T
A
= 55
C
Supply Current vs Supply Voltage
COMMON MODE VOLTAGE (V)
4.0
INPUT BIAS CURRENT (nA)
2000
6000
5.6
1490/91 G03
30
10
4000
20
0
10
4.4
4.8
5.2
44
T
A
=
125
C
T
A
=
55
C
T
A
=
25
C
V
S
= 5V, 0V
TOTAL SUPPLY VOLTAGE (V)
0
CHANGE IN INPUT OFFSET VOLTAGE (
V)
200
400
4
1490/91 G02
0
200
100
300
100
300
400
1
2
3
5
T
A
=
25
C
T
A
=
125
C
T
A
=
55
C
Minimum Supply Voltage
Input Bias Current
vs Common Mode Voltage
Output Saturation Voltage
vs Input Overdrive
SOURCING LOAD CURRENT (mA)
0.001
0.01
0.1
1
10
0.01
OUTPUT SATURATION VOLTAGE (V)
0.1
1
1490/90 G04
V
S
=
2.5V
V
OD
= 30mV
T
A
= 55
C
T
A
= 125
C
T
A
= 25
C
Output Saturation Voltage
vs Load Current (Output High)
Output Saturation Voltage
vs Load Current (Output Low)
SINKING LOAD CURRENT (mA)
0.001
0.01
0.1
1
10
0.01
OUTPUT SATURATION VOLTAGE (V)
0.1
1
1490/90 G05
V
S
=
2.5V
V
OD
= 30mV
T
A
= 55
C
T
A
= 125
C
T
A
= 25
C
INPUT OVERDRIVE (mV)
0
OUTPUT SATURATION VOLTAGE (mV)
60
80
100
80
1490/91 G06
40
20
50
70
90
30
10
0
20
40
60
10
90
30
50
70
100
V
S
=
2.5V
NO LOAD
OUTPUT HIGH
OUTPUT LOW
0.1Hz to 10Hz Noise Voltage
FREQUENCY (Hz)
1
40
INPUT NOISE VOLTAGE DENSITY (nV/
Hz)
50
60
70
10
100
1k
1490/91 G08
30
80
FREQUENCY (Hz)
1
INPUT NOISE CURRENT DENSITY (pA/
Hz)
10
100
1k
1490/91 G09
0.20
0.25
0.30
0.35
0.15
0.10
0.05
0
TIME (SEC)
NOISE VOLTAGE (400nV/DIV)
2
4
6
8
1490 G07
10
1
0
3
5
7
9
V
S
=
2.5V
Noise Voltage Density
vs Frequency
Input Noise Current vs Frequency
PDF 
ZIP