LT1490A
Dual Over-The-Top
Micropower Rail-to-Rail
Input and Output Op Amp
FEATURES
s
s
s
s
s
s
DESCRIPTIO
s
s
s
s
s
s
s
s
s
Low Input Offset Voltage: 500
µ
V Max
Output Swings to 10mV Max from V
–
Rail-to-Rail Input and Output
µ
Micropower: 50µA/Amplifier Max
MSOP Package
Over-The-Top
TM
Input Common Mode Range Extends
44V Above V
–
, Independent of V
+
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
The LT
®
1490A is an enhanced version of the popular LT1490
op amp with improved input offset voltage (500µV max) and
output voltage swing (10mV max from V
–
). It is recom-
mended for all new designs. The LT1490A operates on all
single and split supplies with a total voltage of 2V to 44V,
drawing only 40µA of quiescent current per amplifier. It is
reverse supply protected; it draws virtually no current for
reverse supply up to 18V. The input range of the LT1490A
includes both supplies and the output swings to both sup-
plies. Unlike most micropower op amps, the LT1490A can
drive heavy loads; its rail-to-rail output drives 20mA. The
LT1490A is unity-gain stable and drives all capacitive loads
up to 10,000pF when optional 0.22µF and 150Ω compensa-
tion is used.
The LT1490A has a unique input stage that operates 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 resistors
protect the inputs for faults below the negative supply up to
15V. There is no phase reversal of the output for inputs 15V
below V
–
or 44V above V
–
, independent of V
+
.
The LT1490A dual op amp is available in the 8-pin MSOP,
PDIP and SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Over-The-Top is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
CHARGER
VOLTAGE
Battery Monitor
R
S
0.2Ω
I
BATT
RA
2k
R
A
´
2k
+
1/2 LT1490A
Q1
2N3904
–
1/2 LT1490A
LOGIC
–
Q2
2N3904
+
R
B
2k
R
B
´
2k
LOAD
+
1/2 LT1490A
LOGIC HIGH (5V) = CHARGING
LOGIC LOW (0V) = DISCHARGING
–
R
G
10k
S1
10k
+
1/2 LT1490A
V
OUT
+
V
BATT
= 12V
–
90.9k
14901A TA01
V
OUT
V
I
BATT
=
=
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
U
U
1
LT1490A
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
Total Supply Voltage (V
+
to V
–
) ............................. 44V
Differential Input Voltage ........................................ 44V
Input Current .....................................................
±12mA
Output Short-Circuit Duration (Note 2) ........ Continuous
Junction Temperature .......................................... 150°C
Operating Temperature Range
(Note 3) ............................................. – 40°C to 85°C
Specified Temperature Range (Note 4) .. – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
TOP VIEW
OUT A
–IN A
+IN A
V
–
1
2
3
4
8
7
6
5
V
+
OUT B
–IN B
+IN B
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
LT1490ACMS8
LT1490AIMS8
MS8 PART MARKING
LTNG
LTPU
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 250°C/ W
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
OS
PARAMETER
Input Offset Voltage (Note 5)
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 unless otherwise noted. (Note 4)
CONDITIONS
N8, S8 Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
MS8 Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
Input Offset Voltage Drift (Note 9)
– 40°C
≤
T
A
≤
85°C
V
CM
= 44V (Note 6)
q
q
I
OS
I
B
Input Offset Current
Input Bias Current
V
CM
= 44V (Note 6)
V
S
= 0V
Input Noise Voltage
0.1Hz to 10Hz
f = 1kHz
f = 1kHz
Differential
Common Mode, V
CM
= 0V to 44V
e
n
i
n
R
IN
Input Noise Voltage Density
Input Noise Current Density
Input Resistance
2
U
U
W
W W
U
W
ORDER PART
NUMBER
LT1490ACN8
LT1490ACS8
LT1490AIN8
LT1490AIS8
S8 PART MARKING
1490A
1490AI
N8 PACKAGE
8-LEAD PDIP
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 130°C/ W (N8)
T
JMAX
= 150°C,
θ
JA
= 190°C/ W (S8)
MIN
TYP
110
MAX
500
700
800
1000
1200
1400
4
0.8
0.8
8
10
UNITS
µV
µV
µV
µV
µV
µV
µV/°C
nA
µA
nA
µA
nA
µV
P-P
nV/√Hz
pA/√Hz
MΩ
MΩ
220
q
q
q
q
q
q
q
2
0.2
1
3
0.3
1
50
0.03
6
4
17
11
LT1490A
ELECTRICAL CHARACTERISTICS
SYMBOL
C
IN
CMRR
A
VOL
PARAMETER
Input Capacitance
Input Voltage Range
Common Mode Rejection Ratio
(Note 6)
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
OL
Output Voltage Swing Low
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
OH
Output Voltage Swing High
V
S
= 3V, No Load
V
S
= 3V, I
SOURCE
= 5mA
V
S
= 5V, No Load
V
S
= 5V, I
SOURCE
= 10mA
I
SC
Short-Circuit Current (Note 2)
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
I
S
GBW
Supply Current per Amplifier
(Note 7)
Gain Bandwidth Product
(Note 6)
Slew Rate
(Note 8)
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
I
S
= – 100µA per Amplifier
V
S
= 2.5V to 12.5V, V
CM
= V
O
= 1V
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
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 unless otherwise noted. (Note 4)
CONDITIONS
MIN
0
84
80
200
133
100
400
250
200
98
98
1500
TYP
4.6
44
MAX
UNITS
pF
V
dB
dB
V/mV
V/mV
V/mV
V/mV
V/mV
V/mV
10
450
10
500
500
mV
mV
mV
mV
mV
V
V
V
V
mA
mA
mA
mA
dB
2.5
50
55
V
V
µA
µA
kHz
kHz
kHz
V/µs
V/µs
V/µs
1500
3
250
3
250
330
2.95
2.55
4.95
4.30
10
10
15
15
84
18
2.978
2.6
4.978
4.6
15
30
25
30
98
2
27
40
110
100
90
0.035
0.031
0.030
180
SR
0.06
The
q
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
S
=
±15V
unless otherwise noted. (Note 4)
SYMBOL
V
OS
PARAMETER
Input Offset Voltage (Note 5)
CONDITIONS
N8, S8 Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
MS8 Package
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
q
q
MIN
TYP
150
MAX
700
950
1100
1200
1350
1500
UNITS
µV
µV
µV
µV
µV
µV
250
q
q
3
LT1490A
ELECTRICAL CHARACTERISTICS
SYMBOL
I
OS
I
B
e
n
i
n
R
IN
C
IN
CMRR
A
VOL
PARAMETER
Input Offset Voltage Drift (Note 9)
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
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
q
The
q
denotes specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
S
=
±15V
unless otherwise noted. (Note 4)
CONDITIONS
– 40°C
≤
T
A
≤
85°C
q
q
q
MIN
TYP
2
0.2
1
1
50
0.03
MAX
6
0.8
8
UNITS
µV/°C
nA
nA
µV
P-P
nV/√Hz
pA/√Hz
MΩ
MΩ
pF
0.1Hz to 10Hz
f = 1kHz
f = 1kHz
Differential
Common Mode, V
CM
= – 15V to 14V
6
17
15000
4.6
29
98
250
– 15
80
100
75
50
±14.9
±14.5
±14.5
±20
±15
±10
88
V
dB
V/mV
V/mV
V/mV
V
V
V
mA
mA
mA
dB
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 LT1490AC and LT1490AI are guaranteed functional over the
operating temperature range of – 40°C to 85°C.
Note 4:
The LT1490AC is guaranteed to meet specified performance from
0°C to 70°C. The LT1490AC is designed, characterized and expected to
meet specified performance from – 40°C to 85°C but is not tested or QA
sampled at these temperatures. The LT1490I is guaranteed to meet
specified performance from –40°C to 85°C.
Note 5:
ESD (Electrostatic Discharge) sensitive device. Extensive use of
ESD protection devices are used internal to the LT1490A. However, high
electrostatic discharge can damage or degrade the device. Use proper
ESD handling precautions.
Note 6:
V
S
= 5V limits are guaranteed by correlation to V
S
= 3V and
V
S
=
±15V
tests.
Note 7:
V
S
= 3V limits are guaranteed by correlation to V
S
= 5V and
V
S
=
±15V
tests.
Note 8:
Guaranteed by correlation to slew rate at V
S
=
±15V
and GBW
at V
S
= 3V and V
S
=
±15V
tests.
Note 9:
This parameter is not 100% tested.
4
LT1490A
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Supply Voltage
80
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
CHANGE IN INPUT OFFSET VOLTAGE (µV)
SUPPLY CURRENT PER AMPLIFIER (µA)
INPUT BIAS CURRENT (nA)
T
A
= –55°C
Output Saturation Voltage
vs Load Current (Output High)
1
V
S
= 5V, 0V
1
OUTPUT SATURATION VOLTAGE (mV)
OUTPUT SATURATION VOLTAGE (V)
OUTPUT SATURATION VOLTAGE (V)
T
A
= 125°C
100m
T
A
= 25°C
T
A
= –55°C
10m
1µ
10µ
1m
10m
100µ
SOURCING LOAD CURRENT (A)
0.1Hz to 10Hz Noise Voltage
INPUT NOISE VOLTAGE DENSITY (nV/√Hz)
INPUT NOISE CURRENT DENSITY (pA/√Hz)
V
S
=
±2.5V
NOISE VOLTAGE (400nV/DIV)
0
1
2
3
4 5 6
TIME (SEC)
7
U W
1490A G01
1490A G04
Minimum Supply Voltage
400
300
200
100
0
–100
–200
–300
T
A
= 125°C
0
3
1
4
2
TOTAL SUPPLY VOLTAGE (V)
5
1490A G02
Input Bias Current
vs Common Mode Voltage
5000
V
S
= 5V, 0V
3000
1000
T
A
= –55°C
30
20
10
0
–10
4.0
5.6
4.4
4.8
5.2
COMMON MODE VOLTAGE (V)
44
1490A G03
T
A
= 25°C
T
A
= –55°C
T
A
= 25°C
T
A
= 125°C
– 400
Output Saturation Voltage
vs Load Current (Output Low)
V
S
= 5V, 0V
Output Saturation Voltage
vs Input Overdrive
100
V
S
= 5V, 0V
90 NO LOAD
80
70
60
50
40
30
20
10
0
0
10
OUTPUT LOW
30
40
20
INPUT OVERDRIVE (mV)
50
1490A G06
100m
T
A
= 125°C
T
A
= 25°C
10m
T
A
= –55°C
OUTPUT HIGH
100m
1m
0.1µ
1µ
10µ 100µ 1m
10m
SINKING LOAD CURRENT (A)
100m
1490A G05
Noise Voltage Density
vs Frequency
80
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
Input Noise Current vs Frequency
70
60
50
40
8
9
10
30
1
10
100
FREQUENCY (Hz)
1k
1490A G08
1
10
100
FREQUENCY (Hz)
1k
1490A G09
1490A G07
5
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