ETC LT1491AHS

LT1490A/LT1491A
Dual/Quad Over-The-Top
Micropower Rail-to-Rail
Input and Output Op Amps
U
FEATURES
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DESCRIPTIO
Low Input Offset Voltage: 500µV Max
Output Swings to 10mV Max from V –
Rail-to-Rail Input and Output
µA/Amplifier Max
Micropower: 50µ
MSOP Package
Over-The-TopTM 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
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APPLICATIO S
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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.
Over-The-Top is a trademark of Linear Technology Corporation.
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TYPICAL APPLICATIO
CHARGER
VOLTAGE
The LT ®1490A/LT1491A are enhanced versions of the popular LT1490/LT1491 dual and quad op amps with improved
input offset voltage (500µV max) and output voltage swing
(10mV max from V –). They are recommended as replacements for the LT1490/LT1491 in all new designs. The
LT1490A/LT1491A 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 virtually no current for reverse
supply up to 18V. The input range of the LT1490A/LT1491A
includes both supplies and the output swings to both supplies. Unlike most micropower op amps, the LT1490A/
LT1491A can drive heavy loads; their rail-to-rail outputs drive
20mA. The LT1490A/LT1491A are unity-gain stable and
drive all capacitive loads up to 10,000pF when optional
0.22µF and 150Ω compensation is used.
The LT1490A/LT1491A have 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. The quad LT1491A is available in
the 14-pin SO and PDIP packages.
Battery Monitor
RS
0.2Ω
RA
2k
IBATT
RA´
2k
+
Q1
2N3904
1/4 LT1491A
–
–
1/4 LT1491A
LOGIC
+
RB
2k
RB´
2k
LOAD
+
Q2
2N3904
LOGIC HIGH (5V) = CHARGING
LOGIC LOW (0V) = DISCHARGING
1/4 LT1491A
–
+
+
RG
10k
VBATT = 12V
S1
1/4 LT1491A
VOUT
–
10k
90.9k
S1 = OPEN, GAIN = 1
S1 = CLOSED, GAIN = 10
RA = RB
VS = 5V, 0V
1490A TA01
VOUT
V
IBATT =
= OUT AMPS
(RS)(RG /RA)(GAIN) GAIN
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1
LT1490A/LT1491A
W W
W
AXI U
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ABSOLUTE
RATI GS
(Note 1)
Total Supply Voltage (V + to V –) ............................. 44V
Differential Input Voltage ........................................ 44V
Input Current ..................................................... ±12mA
Output Short-Circuit Duration (Note 2) ........ Continuous
Operating Temperature Range (Note 3)
LT1490AC/LT1491AC ......................... – 40°C to 85°C
LT1490AI/LT1491AI ........................... – 40°C to 85°C
LT1490AH/LT1491AH ...................... – 40°C to 125°C
Specified Temperature Range (Note 4)
LT1490AC/LT1490AI .......................... – 40°C to 85°C
LT1491AC/LT1491AI .......................... – 40°C to 85°C
LT1490AH/LT1491AH ...................... – 40°C to 125°C
Junction Temperature .......................................... 150°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
U
U
W
PACKAGE/ORDER I FOR ATIO
TOP VIEW
TOP VIEW
OUT A
–IN A
+IN A
V–
1
2
3
4
OUT A
8 V+
–IN A
7 OUT B
6 –IN B
5 +IN B
8
1
2
V
–IN A 2
+
7
OUT B
6
–IN B
+IN B
+IN A 3
+IN A
3
V–
4
5
N8 PACKAGE
8-LEAD PDIP
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 250°C/ W
A
D
V+ 4
A
MS8 PACKAGE
8-LEAD PLASTIC MSOP
14 OUT D
OUT A 1
TOP VIEW
+IN B 5
B
–IN B 6
12 +IN D
11 V –
B
OUT B 7
N PACKAGE
14-LEAD PDIP
TJMAX = 150°C, θJA = 130°C/ W (N8)
TJMAX = 150°C, θJA = 190°C/ W (S8)
13 –IN D
C
10 +IN C
9
–IN C
8
OUT C
S PACKAGE
14-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 110°C/ W (N)
TJMAX = 150°C, θJA = 150°C/ W (S)
ORDER PART
NUMBER
MS8
PART MARKING
ORDER PART
NUMBER
S8
PART MARKING
LT1490ACMS8
LT1490AIMS8
LT1490AHMS8
LTNG
LTPU
LTRK
LT1490ACN8
LT1490ACS8
LT1490AIN8
LT1490AIS8
LT1490AHS8
1490A
1490AI
1490AH
ORDER PART
NUMBER
LT1491ACN
LT1491ACS
LT1491AIN
LT1491AIS
LT1491AHS
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature
range of – 40°C ≤ TA ≤ 85°C, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply unless
otherwise noted. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
VOS
Input Offset Voltage (Note 5)
LT1490A N, S Packages
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1490AC/LT1491AC
LT1490AI/LT1491AI
MIN
TYP
MAX
Input Offset Voltage Drift (Note 9)
2
– 40°C ≤ TA ≤ 85°C
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110
500
700
800
µV
µV
µV
220
1000
1200
1400
µV
µV
µV
2
4
●
●
LT1490A MS8 Package, LT1491A N, S Packages
●
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
●
●
UNITS
µV/°C
LT1490A/LT1491A
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature
range of – 40°C ≤ TA ≤ 85°C, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply unless
otherwise noted. (Note 4)
SYMBOL
PARAMETER
IOS
Input Offset Current
CONDITIONS
VCM = 44V (Note 6)
IB
LT1490AC/LT1491AC
LT1490AI/LT1491AI
MIN
TYP
MAX
Input Bias Current
VCM = 44V (Note 6)
VS = 0V
Input Bias Current Drift
– 40°C ≤ TA ≤ 85°C
UNITS
●
●
0.2
0.8
0.8
nA
µA
●
●
1
3
0.3
8
10
nA
µA
nA
●
2
pA/°C
Input Noise Voltage
0.1Hz to 10Hz
1
µVP-P
en
Input Noise Voltage Density
f = 1kHz
50
nV/√Hz
in
Input Noise Current Density
f = 1kHz
0.015
pA/√Hz
RIN
Input Resistance
Differential
Common Mode, VCM = 0V to 44V
CIN
6
4
Input Capacitance
Input Voltage Range
17
11
MΩ
MΩ
4.6
pF
●
0
CMRR
Common Mode Rejection Ratio
(Note 6)
VCM = 0V to VCC – 1V
VCM = 0V to 44V
●
●
84
80
98
98
AVOL
Large-Signal Voltage Gain
VS = 3V, VO = 500mV to 2.5V, RL = 10k
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
200
133
100
1500
●
●
V/mV
V/mV
V/mV
VS = 5V, VO = 500mV to 4.5V, RL = 10k
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
400
250
200
1500
●
●
V/mV
V/mV
V/mV
VS = 3V, No Load
VS = 3V, ISINK = 5mA
●
●
3
250
10
450
mV
mV
VS = 5V, No Load
VS = 5V, ISINK = 5mA
VS = 5V, ISINK = 10mA
●
●
3
250
330
10
500
500
mV
mV
mV
VS = 3V, No Load
VS = 3V, ISOURCE = 5mA
●
●
2.95
2.55
2.978
2.6
V
V
VS = 5V, No Load
VS = 5V, ISOURCE = 10mA
●
●
4.95
4.30
4.978
4.6
V
V
VOL
VOH
ISC
PSRR
Output Voltage Swing Low
Output Voltage Swing High
Short-Circuit Current (Note 2)
Power Supply Rejection Ratio
V
dB
dB
VS = 3V, Short to GND
VS = 3V, Short to VCC
10
10
15
30
mA
mA
VS = 5V, Short to GND
VS = 5V, Short to VCC
15
15
25
30
mA
mA
84
98
dB
VS = 2.5V to 12.5V, VCM = VO = 1V
Minimum Operating Supply Voltage
Reverse Supply Voltage
44
●
2
●
IS = – 100µA per Amplifier
●
18
2.5
V
50
55
µA
µA
27
Supply Current per Amplifier
(Note 7)
GBW
Gain Bandwidth Product
(Note 6)
f = 1kHz
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
110
100
90
180
●
●
kHz
kHz
kHz
Slew Rate
(Note 8)
AV = – 1, RL = ∞
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
0.035
0.031
0.030
0.06
●
●
V/µs
V/µs
V/µs
SR
40
V
IS
●
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LT1490A/LT1491A
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature
range of – 40°C ≤ TA ≤ 85°C, otherwise specifications are at TA = 25°C. VS = ±15V; VCM = 0V, VOUT = 0V unless otherwise noted. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
VOS
Input Offset Voltage (Note 5)
LT1490A N, S Packages
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
LT1490AC/LT1491AC
LT1490AI/LT1491AI
MIN
TYP
MAX
150
700
950
1100
µV
µV
µV
250
1200
1350
1500
µV
µV
µV
●
2
6
●
●
LT1490A MS8 Package, LT1491A N, S Packages
0°C ≤ TA ≤ 70°C
●
●
– 40°C ≤ TA ≤ 85°C
Input Offset Voltage Drift (Note 9)
– 40°C ≤ TA ≤ 85°C
UNITS
µV/°C
IOS
Input Offset Current
●
0.2
0.8
nA
IB
Input Bias Current
●
1
8
nA
●
5
Input Bias Current Drift
– 40°C ≤ TA ≤ 85°C
pA/°C
Input Noise Voltage
0.1Hz to 10Hz
1
µVP-P
en
Input Noise Voltage Density
f = 1kHz
50
nV/√Hz
in
Input Noise Current Density
f = 1kHz
0.015
pA/√Hz
RIN
Input Resistance
Differential
Common Mode, VCM = – 15V to 14V
17
15000
MΩ
MΩ
CIN
Input Capacitance
4.6
pF
Input Voltage Range
6
●
– 15
CMRR
Common Mode Rejection Ratio
VCM = – 15V to 29V
●
80
98
dB
AVOL
Large-Signal Voltage Gain
VO = ±14V, RL = 10k
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
100
75
50
250
●
●
V/mV
V/mV
V/mV
±14.9
±14.5
±14.5
±14.978
±14.750
±14.670
±25
VO
Output Voltage Swing
No Load
IOUT = ±5mA
IOUT = ±10mA
ISC
Short-Circuit Current (Note 2)
Short to GND
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
●
●
±20
±15
±10
VS = ±1.25V to ±22V
●
88
PSRR
Power Supply Rejection Ratio
IS
Supply Current per Amplifier
●
●
29
●
GBW
SR
4
Gain Bandwidth Product
Slew Rate
f = 1kHz
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
AV = – 1, RL = ∞, VO = ±10V,
Measure at VO = ±5V
0°C ≤ TA ≤ 70°C
– 40°C ≤ TA ≤ 85°C
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●
●
●
●
V
V
V
mA
mA
mA
98
50
V
dB
70
85
µA
µA
125
110
100
200
kHz
kHz
kHz
0.0375
0.07
V/µs
0.0330
0.0300
V/µs
V/µs
LT1490A/LT1491A
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature
range of – 40°C ≤ TA ≤ 125°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply unless otherwise noted. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
VOS
Input Offset Voltage (Note 5)
LT1490AHS8
LT1490AH/LT1491AH
MIN
TYP
MAX
110
500
2500
µV
µV
220
1000
3000
µV
µV
3
6
●
LT1490AHMS8, LT1491AHS
●
Input Offset Voltage Drift (Note 9)
IOS
IB
●
Input Offset Current
●
●
2
1.5
nA
µA
VCM = 44V (Note 6)
●
●
20
15
nA
µA
44
V
Input Bias Current
CMRR
Common Mode Rejection Ratio
(Note 6)
VCM = 0.3V to VCC –1V
VCM = 0.3V to 44V
AVOL
Large-Signal Voltage Gain
VS = 3V, VO = 500mV to 2.5V, RL = 10k
●
0.3
●
●
60
74
200
25
1500
●
V/mV
V/MV
400
50
1500
●
V/mV
V/mV
VS = 5V, VO = 500mV to 4.5V, RL = 10k
VOH
PSRR
Output Voltage Swing Low
Output Voltage Swing High
Power Supply Rejection Ratio
Reverse Supply Voltage
dB
dB
VS = 3V, No Load
VS = 3V, ISINK = 2.5mA
●
●
15
450
mV
mV
VS = 5V, No Load
VS = 5V, ISINK = 2.5mA
●
●
15
500
mV
mV
VS = 3V, No Load
VS = 3V, ISOURCE = 5mA
●
●
2.925
2.350
V
V
VS = 5V, No Load
VS = 5V, ISOURCE = 10mA
●
●
4.925
4.100
V
V
VS = 2.5V to 12.5V, VCM = VO = 1V
●
80
dB
Minimum Operating Supply Voltage
IS
●
IS = – 100µA per Amplifier
●
SR
Gain Bandwidth Product (Note 6)
Slew Rate (Note 8)
50
70
µA
µA
110
60
180
●
kHz
kHz
0.035
0.015
0.06
●
V/µs
V/µs
AV = – 1, RL = ∞
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V
V
40
f = 1kHz
2.5
18
Supply Current per Amplifier (Note 7)
●
GBW
µV/°C
VCM = 44V (Note 6)
Input Voltage Range
VOL
UNITS
5
LT1490A/LT1491A
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature
range of – 40°C ≤ TA ≤ 125°C. VS = ±15V, VCM = 0V, VOUT = 0V unless otherwise noted. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
LT1490AH/LT1491AH
MIN
TYP
MAX
VOS
Input Offset Voltage (Note 5)
LT1490AHS8
150
700
2700
µV
µV
250
1200
3200
µV
µV
3
7
µV/°C
2
nA
20
nA
29
V
●
LT1490AHMS8, LT1491AHS
●
Input Offset Voltage Drift (Note 9)
●
IOS
Input Offset Current
●
IB
Input Bias Current
●
Input Voltage Range
●
–14.7
●
72
●
100
4
CMRR
Common Mode Rejection Ratio
VCM = –14.7V to 29V
AVOL
Large-Signal Voltage Gain
VO = ±14V, RL = 10k
UNITS
dB
250
V/mV
V/mV
VO
Output Voltage Swing
No Load
IOUT = ±2.5mA
●
●
±14.8
±14.3
mV
mV
PSRR
Power Supply Rejection Ratio
VS = ±1.25V to ±22V
●
84
dB
IS
Supply Current per Amplifier
50
●
GBW
SR
Gain Bandwidth Product
Slew Rate
f = 1kHz
6
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µA
µA
125
75
200
●
kHz
kHz
0.0375
0.02
0.07
●
V/µs
V/µs
AV = – 1, RL = ∞
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/LT1491AC and LT1490AI/LT1491AI are guaranteed
functional over the operating temperature range of – 40°C to 85°C. The
LT1490AH/LT1491AH are guaranteed functional over the operating
temperature range of – 40°C to 125°C.
Note 4: The LT1490AC/LT1491AC are guaranteed to meet specified
performance from 0°C to 70°C. The LT1490AC/LT1491AC 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
LT1490AI/LT1491AI are guaranteed to meet specified performance from
–40°C to 85°C. The LT1490AH/LT1491AH are guaranteed to meet
specified performance from – 40°C to 125°C.
70
95
Note 5: ESD (Electrostatic Discharge) sensitive device. Extensive use of
ESD protection devices are used internal to the LT1490A/LT1491A.
However, high electrostatic discharge can damage or degrade the device.
Use proper ESD handling precautions.
Note 6: VS = 5V limits are guaranteed by correlation to VS = 3V and
VS = ±15V tests.
Note 7: VS = 3V limits are guaranteed by correlation to VS = 5V and
VS = ±15V tests.
Note 8: Guaranteed by correlation to slew rate at VS = ±15V and GBW
at VS = 3V and VS = ±15V tests.
Note 9: This parameter is not 100% tested.
LT1490A/LT1491A
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Supply Voltage
TA = 125°C
60
TA = 25°C
50
40
TA = –55°C
30
20
10
0
5
0
10 15 20 25 30 35 40
TOTAL SUPPLY VOLTAGE (V)
400
5000
300
3000
200
100
TA = –55°C
TA = 25°C
0
–100
–200
–300
– 400
45
VS = 5V, 0V
INPUT BIAS CURRENT (nA)
CHANGE IN INPUT OFFSET VOLTAGE (µV)
SUPPLY CURRENT PER AMPLIFIER (µA)
80
70
Input Bias Current
vs Common Mode Voltage
Minimum Supply Voltage
TA = –55°C
10µ
1m
10m
100µ
SOURCING LOAD CURRENT (A)
100
TA = 25°C
TA = –55°C
10m
2
1µ
10µ 100µ 1m
10m
SINKING LOAD CURRENT (A)
7
8
60
50
40
30
9
10
OUTPUT HIGH
20
10
OUTPUT LOW
0
10
30
40
20
INPUT OVERDRIVE (mV)
Input Noise Current vs Frequency
0.35
INPUT NOISE CURRENT DENSITY (pA/√Hz)
100
80
60
40
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0.30
0.25
0.20
0.15
0.10
0.05
0
20
1490A G07
50
1490A G06
1490A G05
INPUT NOISE VOLTAGE DENSITY (nV/√Hz)
4 5 6
TIME (SEC)
70
100m
120
3
80
Noise Voltage Density
vs Frequency
NOISE VOLTAGE (400nV/DIV)
1
VS = 5V, 0V
90 NO LOAD
0
1490A G04
0.1Hz to 10Hz Noise Voltage
44
Output Saturation Voltage
vs Input Overdrive
TA = 125°C
1m
0.1µ
100m
VS = ±2.5V
0 4.0 4.4 4.8 5.2 5.6
COMMON MODE VOLTAGE (V)
1490A G03
OUTPUT SATURATION VOLTAGE (mV)
OUTPUT SATURATION VOLTAGE (V)
OUTPUT SATURATION VOLTAGE (V)
TA = 25°C
0
–0.4
5
VS = 5V, 0V
100m
100m
TA = 125°C
10
–10
1
3
4
2
TOTAL SUPPLY VOLTAGE (V)
0
1
TA = 125°C
TA = 25°C
20
Output Saturation Voltage
vs Load Current (Output Low)
VS = 5V, 0V
1µ
30
1490A G02
Output Saturation Voltage
vs Load Current (Output High)
10m
TA = –55°C
0
TA = 125°C
1490A G01
1
1000
1
10
100
FREQUENCY (Hz)
1k
1490A G08
1
10
100
FREQUENCY (Hz)
1k
1490A G09
7
LT1490A/LT1491A
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Gain and Phase Shift
vs Frequency
Gain Bandwidth Product
vs Temperature
40
30
20
20
0
GAIN
10
–20
0
– 40
–10
– 60
–20
– 80
10
100
FREQUENCY (kHz)
200
VS = ±15V
180
VS = ±1.5V
160
50
25
0
75
TEMPERATURE (°C)
40
200
30
180
170
20
RL = 10k
f = 1kHz
160
COMMON MODE REJECTION RATIO (dB)
220
PHASE MARGIN (DEG)
GAIN BANDWIDTH PRODUCT (kHz)
50
GAIN BANDWIDTH
0
5
10 15 20 25 30 35 40
TOTAL SUPPLY VOLTAGE (V)
100
VS = ±15V
80
VS = ±1.5V
60
40
10
FREQUENCY (kHz)
PHASE MARGIN
250
40
30
20
NEGATIVE SUPPLY
10
0
–10
10
FREQUENCY (kHz)
1
100
1490A G15
Output Impedance vs Frequency
10k
VS = ±15V
VS = ± 2.5V
120
70
60
200
POSITIVE SUPPLY
50
100
50
GAIN BANDWIDTH
150
40
100
30
110
OUTPUT IMPEDANCE (Ω)
300
130
CHANNEL SEPARATION (dB)
VS = ± 2.5V
AV = –1
RF = RG = 100k
f = 1kHz
60
Channel Separation vs Frequency
80
PHASE MARGIN (DEG)
GAIN BANDWIDTH PRODUCT (kHz)
350
VS = ±2.5V
70
1490A G14
1490A G13
Gain Bandwidth Product and
Phase Margin vs Load Resistance
125
–20
1
45
100
PSRR vs Frequency
80
20
10
150
50
25
0
75
TEMPERATURE (°C)
1490A G12
120
240
190
0.04
–50 –25
125
100
CMRR vs Frequency
210
FALLING, VS = ±1.5V
1490A G11
60
230
FALLING, VS = ±15V
120
Gain Bandwidth Product and
Phase Margin vs Supply Voltage
PHASE MARGIN
RISING, VS = ±1.5V
0.08
0.06
140
1490A G10
250
RISING, VS = ±15V
0.10
220
100
–50 –25
–100
1000
–30
1
f = 1kHz
PHASE SHIFT (DEG)
GAIN (dB)
240
60
PHASE
40
80
POWER SUPPLY REJECTION RATIO (dB)
50
100
Slew Rate vs Temperature
0.12
SLEW RATE (V/µs)
VS = ±2.5V
GAIN BANDWIDTH PRODUCT (kHz)
70
60
260
100
90
80
70
60
1k
AV = 100
100
AV = 10
10
1
AV = 1
50
50
1
10
LOAD RESISTANCE (kΩ)
20
100
1490A G16
8
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40
0.1
1
10
FREQUENCY (kHz)
100
1490A G17
0.1
0.1
1
10
FREQUENCY (kHz)
100
1490A G18
LT1490A/LT1491A
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Undistorted Output Swing
vs Frequency
35
10
0
–2
–4
40
AV = 1
AV = 2
AV = 10
AV = 5
30
20
40
60 80 100 120 140 160
SETTLING TIME (µs)
10
100
1000
CAPACITIVE LOAD (pF)
10000
1490A G19
1490A F20
1490A G21
Total Harmonic Distortion + Noise
vs Frequency
Total Harmonic Distortion + Noise
vs Load Resistance
Total Harmonic Distortion + Noise
vs Output Voltage
0.01
1
RL = 10k
VCM = HALF SUPPLY
f = 1kHz
1
VS = ±1.5V
VIN = ±1V
0.1
VS = 3V, 0V
VIN = 0.5V TO 2.5V
AV = –1
VS = ±1.5V
0.1
AV = 1
VS = 3V, 0V
VS = 3V, 0V
VIN = 0.2V TO 2.2V
AV = 1
1
0.1
FREQUENCY (kHz)
10
0.001
0.1
AV = –1
VS = 3V, 0V
0.001
10
1
LOAD RESISTANCE TO GROUND (kΩ)
1490A G22
Open-Loop Gain
AV = 1
VS = ±1.5V
0.01
0.01
AV = –1
0.001
0.01
10
VS = 3V TOTAL
AV = 1
VIN = 2VP-P AT 1kHz
THD + NOISE (%)
10
VS = 3V, 0V
VOUT = 2VP-P
VCM = 1.2V
RL = 50k
0.1
CHANGE IN INPUT OFFSET VOLTAGE
(100µV/DIV)
50
0
0
100
60
10
AV = 1
–10
1
10
FREQUENCY (kHz)
70
20
AV = –1
–8
THD + NOISE (%)
1
2
–6
VS = 5V, 0V
0
0.1
10
80
AV = 1
4
VS = 5V, 0V
ISOURCE = 170µA
90
OVERSHOOT (%)
OUTPUT STEP (V)
OUTPUT SWING (VP-P)
15
100
AV = –1
6
20
Capacitive Load Handling,
Overshoot vs Capacitive Load
VS = ±15V
8
25
5
THD + NOISE (%)
10
DISTORTION ≤1%
VS = ±15V
30
Settling Time to 0.1%
vs Output Step
100
0
1
2
OUTPUT VOLTAGE (VP-P)
1490A G24
1490A G23
Large-Signal Response
3
Small-Signal Response
VS = ±15V
RL = 2k
RL = 10k
RL = 50k
–10V
0V
10V
OUTPUT VOLTAGE (5V/DIV)
1490A G25
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VS = ±15V
AV = –1
1490A G26
VS = ±15V
AV = 1
1490A G27
9
LT1490A/LT1491A
U
W
U U
APPLICATIO S I FOR ATIO
Supply Voltage
The positive supply pin of the LT1490A/LT1491A should
be bypassed with a small capacitor (about 0.01µF) within
an inch of the pin. When driving heavy loads an additional
4.7µF electrolytic capacitor should be used. When using
split supplies, the same is true for the negative supply pin.
The LT1490A/LT1491A are protected against reverse battery voltages up to 18V. In the event a reverse battery
condition occurs, the supply current is less than 1nA.
The LT1490A/LT1491A can be shut down by removing V +.
In this condition the input bias current is typically less than
0.5nA, even if the inputs are 44V above the negative
supply.
When operating the LT1490A/LT1491A on total supplies
of 20V or more, the supply must not rise to its final voltage
in less than 1µs. This is especially true if low ESR bypass
capacitors are used. A series RLC circuit is formed from
the supply lead inductance and the bypass capacitor. A
resistance of 7.5Ω in the supply or in the bypass capacitor
will dampen the tuned circuit enough to limit the rise time.
Inputs
The LT1490A/LT1491A have two input stages, NPN and
PNP (see the Simplified Schematic), resulting in three
distinct operating regions as shown in the Input Bias
Current vs Common Mode typical performance curve.
For input voltages about 0.8V or more below V +, the PNP
input stage is active and the input bias current is typically
– 1nA. When the input voltage is about 0.5V or less from
V +, the NPN input stage is operating and the input bias
current is typically 25nA. Increases in temperature will
cause the voltage at which operation switches from the
PNP stage to the NPN stage to move towards V +. The input
offset voltage of the NPN stage is untrimmed and is
typically 600µV.
A Schottky diode in the collector of each NPN transistor of
the NPN input stage allows the LT1490A/LT1491A to operate with either or both of their inputs above V +. At about
0.3V above V + the NPN input transistor is fully saturated
and the input bias current is typically 3µA at room temperature. The input offset voltage is typically 700µV when
10
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operating above V +. The LT1490A/LT1491A will operate
with their inputs 44V above V – regardless of V +.
The inputs are protected against excursions as much as
15V below V – by an internal 1k resistor in series with
each input and a diode from the input to the negative
supply. There is no output phase reversal for inputs up to
15V below V –. There are no clamping diodes between the
inputs and the maximum differential input voltage is 44V.
Output
The output voltage swing of the LT1490A/LT1491A is
affected by input overdrive as shown in the typical performance curves.
The output of the LT1490A/LT1491A can be pulled up to
18V beyond V + with less than 1nA of leakage current,
provided that V + is less than 0.5V.
The normally reverse-biased substrate diode from the
output to V – will cause unlimited currents to flow when the
output is forced below V –. If the current is transient and
limited to 100mA, no damage will occur.
The LT1490A/LT1491A are internally compensated to
drive at least 200pF of capacitance under any output
loading conditions. A 0.22µF capacitor in series with a
150Ω resistor between the output and ground will compensate these amplifiers for larger capacitive loads, up to
10,000pF, at all output currents.
Distortion
There are two main contributors of distortion in op amps:
output crossover distortion as the output transitions
from sourcing to sinking current and distortion caused
by nonlinear common mode rejection. Of course, if the op
amp is operating inverting there is no common mode
induced distortion. When the LT1490A/LT1491A switch
between input stages there is significant nonlinearity in
the CMRR. Lower load resistance increases the output
crossover distortion, but has no effect on the input stage
transition distortion. For lowest distortion the LT1490A/
LT1491A should be operated single supply, with the
output always sourcing current and with the input voltage swing between ground and (V + – 0.8V). See the
Typical Performance Characteristics curves.
LT1490A/LT1491A
U
W
U U
APPLICATIO S I FOR ATIO
Gain
in single supply applications where the load is returned to
ground. The typical performance photo of Open-Loop
Gain for various loads shows the details.
The open-loop gain is almost independent of load when
the output is sourcing current. This optimizes performance
U
TYPICAL APPLICATIO S
Square Wave Oscillator
Optional Output Compensation for
Capacitive Loads Greater Than 200pF
59k
5V
100k
+
1/2 LT1490A
100k
+
VIN
1/2 LT1490A
VOUT
CL ≤ 10,000pF
–
–
R
50k
C
0.1µF
1490A TA02
0.22µF
150Ω
f= 1
2RC
VOUT = 5VP-P WITH 5V SUPPLY
IS = 200µA
1490A TA04
AT VS = 5V, R = 50k, C = 1nF
OUTPUT IS 5kHz SLEW LIMITED TRIANGLE WAVE
W
W
SI PLIFIED SCHE ATIC
V+
Q2
Q1
D1
R1
30k
Q3
Q22
D3
D2
R2
1k
Q4
Q19
– IN
Q17
Q7
R3
1k
+
Q8
Q11
OUT
Q16
+IN
2µA
Q18
Q15
Q9
Q5
Q20
Q12
Q6
D4
D5
Q10
Q13
Q14
R4
40k
Q21
R5
40k
V–
ONE AMPLIFIER
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1490A SS
11
LT1490A/LT1491A
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
MS8 Package
8-Lead Plastic MSOP
(LTC DWG # 05-08-1660)
0.118 ± 0.004*
(3.00 ± 0.102)
8
7 6
5
0.118 ± 0.004**
(3.00 ± 0.102)
0.193 ± 0.006
(4.90 ± 0.15)
1
2 3
4
0.040 ± 0.006
(1.02 ± 0.15)
0.007
(0.18)
0.034 ± 0.004
(0.86 ± 0.102)
0° – 6° TYP
SEATING
PLANE 0.012
(0.30)
0.0256
REF
(0.65)
BSC
0.021 ± 0.006
(0.53 ± 0.015)
0.006 ± 0.004
(0.15 ± 0.102)
MSOP (MS8) 1098
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,
PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.400*
(10.160)
MAX
8
7
6
5
1
2
3
4
0.255 ± 0.015*
(6.477 ± 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.009 – 0.015
(0.229 – 0.381)
(
+0.035
0.325 –0.015
8.255
+0.889
–0.381
)
0.045 – 0.065
(1.143 – 1.651)
0.065
(1.651)
TYP
0.100
(2.54)
BSC
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
12
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0.130 ± 0.005
(3.302 ± 0.127)
0.125
(3.175) 0.020
MIN (0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
N8 1098
LT1490A/LT1491A
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
8
7
6
5
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
0°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
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2
3
4
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
SO8 1298
13
LT1490A/LT1491A
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
N Package
14-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.770*
(19.558)
MAX
14
13
12
11
10
9
8
1
2
3
4
5
6
7
0.255 ± 0.015*
(6.477 ± 0.381)
0.130 ± 0.005
(3.302 ± 0.127)
0.300 – 0.325
(7.620 – 8.255)
0.045 – 0.065
(1.143 – 1.651)
0.020
(0.508)
MIN
0.065
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
+0.035
0.325 –0.015
0.005
(0.125)
MIN 0.100
(2.54)
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
BSC
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
(
+0.889
8.255
–0.381
14
)
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0.125
(3.175)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
N14 1098
LT1490A/LT1491A
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S Package
14-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.337 – 0.344*
(8.560 – 8.738)
14
13
12
11
10
9
8
0.228 – 0.244
(5.791 – 6.197)
0.150 – 0.157**
(3.810 – 3.988)
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
2
3
4
5
6
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
0° – 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
7
0.050
(1.270)
BSC
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representationCopyRight
that the interconnection
of its circuits as described herein will not infringe on existing patent rights.
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2003
S14 1298
15
LT1490A/LT1491A
U
TYPICAL APPLICATIO
Ring-Tone Generator
60V
R16
100k
R2
47k
R3
10k
C2
0.47µF
3
+
R1
1/4 LT1491A
33k 2
1
D1
1N4148
R5
100k
5
–
7
R9
300k
R11
10k
10
Z1
15V
100k
+
1/4 LT1491A
R7
16k
–
C4
0.068µF
9
8
13
–
R4
1.6M
R8
620k
CADENCE OSCILLATOR
R10
620k
R12
SMOOTHING FILTER 10k
R14
10k
R13
130k
R15
47k
20Hz OSCILLATOR
C5
0.01µF
+
R24
11 420
14
C7
47µF
R18
100Ω
R26
2k
R23
4.7k
OPTO1*
R25
4.7k
Q5
2N3904
Z2
15V
*LED OF OPTO1 ILLUMINATES WHEN THE PHONE IS OFF THE HOOK
SEE DESIGN NOTE DN134 FOR A DISCUSSION OF THE CIRCUIT
R17
620Ω
4
–
1/4 LT1491A
12
C1
1µF
Q3
2N3904
C3
0.047µF
+
1/4 LT1491A
6
Q1
IRF628
R6
10k
R19
620Ω
UP TO
LOAD TEN
PHONES
Q4
2N3906
Q2
IRF9620
R21
150Ω
C6
0.033µF
POWER AMPLIFIER
–180V
R20
100k
1490A TA03
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1366/LT1367
Dual/Quad Precision, Rail-to-Rail Input and Output Op Amps
475µV VOS(MAX), 500V/mV AVOL(MIN), 400kHz GBW
LT1636
Single Over-The-Top Micropower Rail-to-Rail Input and Output
Op Amp
55µA Supply Current, VCM Extends 44V above VEE,
Independent of VCC, MSOP Package, Shutdown Function
LT1638/LT1639
Dual/Quad 1.2MHz Over-The-Top Micropower, Rail-to-Rail
Input and Output Op Amps
0.4V/µs Slew Rate, 230µA Supply Current per Amplifier
LT1782
Micropower, Over-The-Top, SOT-23, Rail-to-Rail
Input and Output Op Amp
SOT-23, 800µV VOS(MAX), IS =55µA (Max),
Gain-Bandwidth = 200kHz, Shutdown Pin
LT1783
1.2MHz, Over-The-Top, Micropower, Rail-to-Rail
Input and Output Op Amp
SOT-23, 800µV VOS(MAX), IS =300µA (Max),
Gain-Bandwidth = 1.2MHz, Shutdown Pin
16
Linear Technology Corporation
14901af LT/TP 0600 4K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
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(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 2000