1
LT1494/LT1495/LT1496
TYPICAL APPLICATION
U
APPLICATIO S
U
FEATURES
1.5µA Max, Single, Dual
and Quad Over-The-Top Precision
Rail-to-Rail Input and Output Op Amps
■
Low Supply Current: 1.5
µ
A Max
■
Rail-to-Rail Input and Output
■
Low Offset Voltage: 375
µ
V Max
■
Operating Temperature Range: –40
°
C to 125
°
C
■
Over-The-Top
TM
Inputs Operate Above V
+
■
Wide Supply Range: 2.2V to 36V
■
Single Supply Input Range: –0.3V to 36V
■
Low Input Bias Current: 250pA
■
Low Input Offset Current: 20pA
■
High A
VOL
: 100V/mV Minimum Driving 100kΩ Load
■
Output Sources and Sinks 500µA Load Current
■
Reverse Battery Protected to 18V
The LT
®
1494/LT1495/LT1496 are the lowest power
(I
S
≤ 1.5µA) op amps with precision specifications. The
extremely low supply current is combined with excellent
amplifier specifications: input offset voltage is 375µV
maximum with a typical drift of only 0.4µV/°C, input offset
current is 100pA maximum. A minimum open-loop gain
(A
VOL
) of 100V/mV ensures that gain errors are small. The
device characteristics change little over the supply range
of 2.2V to ±15V. Supply rejection is 90dB and the common
mode rejection ratio is 90dB. Operation is specified for 3V,
5V and ±15V supplies. Reverse battery protection
(–18V␣ min) and inputs that operate above the positive
supply make the LT1494/LT1495/LT1496 easy to use in
harsh environments.
The low bias currents and offset current of the amplifier
permit the use of megohm level source resistors without
introducing significant errors. Voltage noise at 4µV
P-P
is
remarkably low considering the low supply current.
The LT1494 is available in the 8-Pin MSOP, PDIP and SO
packages.The LT1495 is available in plastic 8-Pin PDIP
and SO packages with the standard dual op amp pinout.
The LT1496 is available in 14-Pin SO and PDIP packages.
■
Battery- or Solar-Powered Systems
■
Portable Instrumentation
■
Remote Sensor Amplifier
■
Micropower Filter
Micropower Integrating Current Sense
+
–
1/2 LT1495
0.1µF
RESET
R
I
1M
1M
R
S
0.1Ω
LOAD
+
–
1/2 LT1495
I
L
V
CC
10M10M
V
CC
V
O
OUTPUT SWITCHES
WHEN I
L
dt = 0.98 V
CC
I
S
= 3µA DURING INTEGRATION; I
S
= 5µA END OF INTEGRATION
C = (4.9A)(SEC) FOR V
CC
= 5V
R
I
R
S
()
1495 TA01
200k
TC VOS Distribution
TC V
OS
(µV/°C)
UNITS
30
25
20
15
10
5
0
–1.2 –0.4 0.4 1.2
1495 TA02
2.0–1.6–2.0 –0.8 0 0.8 1.6
100 AMPLIFIERS
V
S
= ±2.5V
–40°C TO 85°C
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
Over-The-Top is a trademark of Linear Technology Corporation.
2
LT1494/LT1495/LT1496
Total Supply Voltage (V
+
to V
–
) .............................. 36V
Differential Input Voltage ......................................... 36V
Input Current ...................................................... ±10mA
Output Short-Circuit Duration.......................Continuous
Operating Temperature Range (Note 2)
LT1494C/LT1495C/LT1496C .............. –40°C to 85°C
LT1494I/LT1495I/LT1496I ................. –40°C to 85°C
LT1494H/LT1495H/LT1496H ........... –40°C to 125°C
Specified Temperature Range (Note 3)
LT1494C/LT1495C/LT1496C .............. –40°C to 85°C
LT1494I/LT1495I/LT1496I ................. –40°C to 85°C
LT1494H/LT1495H/LT1496H ........... –40°C to 125°C
Storage Temperature Range ................. –65°C to 150°C
Junction Temperature...........................................150°C
Lead Temperature (Soldering, 10 sec)..................300°C
ABSOLUTE MAXIMUM RATINGS
W
WW
U
PACKAGE/ORDER INFORMATION
W
UU
ORDER PART
NUMBER
Consult LTC Marketing for parts specified with wider operating temperature ranges.
T
JMAX
= 150°C, θ
JA
= 130°C/ W (N)
T
JMAX
= 150°C, θ
JA
= 160°C/ W (S)
T
JMAX
= 150°C, θ
JA
= 130°C/ W (N8)
T
JMAX
= 150°C, θ
JA
= 190°C/W (S8)
S8 PART MARKING
1495
1495I
1495H
LT1495CN8
LT1495CS8
LT1495IN8
LT1495IS8
LT1495HS8
ORDER PART
NUMBER
LT1496CN
LT1496CS
LT1496IN
LT1496IS
LT1496HS
(Note 1)
1
2
3
4
8
7
6
5
TOP VIEW
OUT A
–IN A
+IN A
V
–
V
+
OUT B
–IN B
+IN B
N8 PACKAGE
8-LEAD PDIP S8 PACKAGE
8-LEAD PLASTIC SO
A
B
1
2
3
4
5
6
7
TOP VIEW
N PACKAGE
14-LEAD PDIP S PACKAGE
14-LEAD PLASTIC SO
14
13
12
11
10
9
8
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
AD
BC
ORDER PART
NUMBER
MS8 PART MARKING
1494
1494I
1494H
LT1494CN8
LT1494CS8
LT1494IN8
LT1494IS8
LT1494HS8
ORDER PART
NUMBER
S8 PART MARKING
LT1494CMS8
LT1494IMS8
LTFF
LTFG
TOP VIEW
NC
V
+
OUT
NC
NC
–IN
+IN
V
–
1
2
3
4
8
7
6
5
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)
T
JMAX
= 150°C, θ
JA
= 250°C/W
1
2
3
4
8
7
6
5
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
NC
V
+
OUT
NC
NC
–IN
+IN
V
–
3
LT1494/LT1495/LT1496
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage V
S
= 5V 150 375 µV
V
S
= 3V 200 475 µV
V
S
= 5V, MS8 Package 150 475 µV
V
S
= 3V, MS8 Package 200 575 µV
I
B
Input Bias Current (Note 5) 250 1000 pA
V
CM
= 10V (Note 6) 180 360 nA
I
OS
Input Offset Current (Note 5) 20 100 pA
Input Noise Voltage 0.1Hz to 10Hz 4 µV
P-P
e
n
Input Noise Voltage Density f = 100Hz 185 nV/√Hz
i
n
Input Noise Current Density f = 100Hz 10 fA/√Hz
A
VOL
Large-Signal Voltage Gain V
S
= 5V, V
O
= 0.25V to 4.5V, R
L
= 100k 100 500 V/mV
V
S
= 3V, V
O
= 0.25V to 2.5V, R
L
= 100k 50 250 V/mV
Input Voltage Range 0 36 V
CMRR Common Mode Rejection Ratio V
CM
= 0V to 4V, V
S
= 5V 90 106 dB
V
CM
= 0V to 10V, V
S
= 5V 74 95 dB
PSRR Power Supply Rejection Ratio V
S
= 2.2V to 12V, V
CM
= V
O
= 0.5V 90 99 dB
Minimum Operating Supply Voltage 2.1 2.2 V
V
OL
Output Voltage Swing LOW No Load 50 100 mV
I
SINK
= 100µA 210 410 mV
V
OH
Output Voltage Swing HIGH No Load V
+
– 0.07 V
+
– 0.035 V
I
SOURCE
= 100µAV
+
– 0.32 V
+
– 0.160 V
I
SC
Short-Circuit Current (Note 5) 0.7 1.3 mA
I
S
Supply Current per Amplifier (Note 6) 1.0 1.5 µA
Reverse Supply Voltage I
S
= 10µA per Amplifier –18 V
SR Slew Rate A
V
= –1, V
S
= ±5V 0.4 1.0 V/ms
GBW Gain Bandwidth Product f = 100Hz 2.7 kHz
ELECTRICAL CHARACTERISTICS
TA = 25°C, VS = 5V, 0V; VS = 3V, 0V; VCM = VO = half supply, unless otherwise noted.
4
LT1494/LT1495/LT1496
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage V
S
= 5V ●200 475 µV
V
S
= 3V ●250 575 µV
V
S
= 5V, MS8 Package ●200 575 µV
V
S
= 3V, MS8 Package ●250 675 µV
V
OS
TC Input Offset Voltage Drift (Note 4) ●0.4 2 µV/°C
I
B
Input Bias Current (Note 5) ●250 1700 pA
V
CM
= 10V (Note 6) ●275 nA
I
OS
Input Offset Current (Note 5) ●20 170 pA
A
VOL
Large-Signal Voltage Gain V
S
= 5V, V
O
= 0.25V to 4.5V, R
L
= 100k ●55 215 V/mV
V
S
= 3V, V
O
= 0.25V to 2.5V, R
L
= 100k ●30 115 V/mV
Input Voltage Range ●0.2 36 V
CMRR Common Mode Rejection Ratio V
CM
= 0.2V to 4V, V
S
= 5V ●88 106 dB
V
CM
= 0.2V to 10V, V
S
= 5V ●75 dB
PSRR Power Supply Rejection Ratio V
S
= 2.7V to 12V, V
CM
= V
O
= 0.5V ●88 99 dB
Minimum Operating Supply Voltage ●2.6 2.7 V
V
OL
Output Voltage Swing LOW No Load ●60 120 mV
I
SINK
= 100µA●245 490 mV
V
OH
Output Voltage Swing HIGH No Load ●V
+
– 0.10 V
+
– 0.05 mV
I
SOURCE
= 100µA●V
+
– 0.38 V
+
– 0.19 mV
I
SC
Short-Circuit Current (Note 5) ●0.4 0.9 mA
I
S
Supply Current per Amplifier (Note 6) ●1.5 2.3 µA
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C, VS = 5V, 0V; VS = 3V, 0V; VCM = VO =
half supply, unless otherwise noted. (Note 3)
The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C, VS = 5V, 0V; VS = 3V, 0V; VCM = VO = half
supply, unless otherwise noted. (Note 3)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage V
S
= 5V ●175 425 µV
V
S
= 3V ●225 525 µV
V
S
= 5V, MS8 Package ●175 525 µV
V
S
= 3V, MS8 Package ●225 625 µV
V
OS
TC Input Offset Voltage Drift (Note 4) ●0.4 2 µV/°C
I
B
Input Bias Current (Note 5) ●250 1200 pA
V
CM
= 10V (Note 6) ●240 500 nA
I
OS
Input Offset Current (Note 5) ●20 120 pA
A
VOL
Large-Signal Voltage Gain V
S
= 5V, V
O
= 0.25V to 4.5V, R
L
= 100k ●75 280 V/mV
V
S
= 3V, V
O
= 0.25V to 2.5V, R
L
= 100k ●40 150 V/mV
Input Voltage Range ●0.2 36 V
CMRR Common Mode Rejection Ratio V
CM
= 0.2V to 4V, V
S
= 5V ●89 106 dB
V
CM
= 0.2V to 10V, V
S
= 5V ●64 85 dB
PSRR Power Supply Rejection Ratio V
S
= 2.4V to 12V, V
CM
= V
O
= 0.5V ●89 99 dB
Minimum Operating Supply Voltage ●2.3 2.4 V
V
OL
Output Voltage Swing LOW No Load ●55 110 mV
I
SINK
= 100µA●225 450 mV
V
OH
Output Voltage Swing HIGH No Load ●V
+
– 0.08 V
+
– 0.04 V
I
SOURCE
= 100µA●V
+
– 0.36 V
+
– 0.18 V
I
SC
Short-Circuit Current (Note 5) ●0.6 1.1 mA
I
S
Supply Current per Amplifier (Note 6) ●1.2 1.8 µA
5
LT1494/LT1495/LT1496
ELECTRICAL CHARACTERISTICS
TA = 25°C, VS = ±15V, VCM = VO = 0V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage 200 575 µV
MS8 Package 200 675 µV
I
B
Input Bias Current 25 1000 pA
I
OS
Input Offset Current 20 100 pA
A
VOL
Large-Signal Voltage Gain V
O
= ±10V, R
L
= 100k 100 360 V/mV
Input Voltage Range –15 21 V
CMRR Common Mode Rejection Ratio V
CM
= –15V to 14V 100 120 dB
PSRR Power Supply Rejection Ratio V
S
= ±5V to ±15V 96 120 dB
V
OL
Output Voltage Swing LOW R
L
= 1M –14.85 –14.70 V
R
L
= 100k –14.75 –14.50 V
V
OH
Output Voltage Swing HIGH R
L
= 1M 14.78 14.89 V
R
L
= 100k 14.62 14.81 V
I
SC
Short-Circuit Current 0.7 1.5 mA
I
S
Supply Current per Amplifier 1.4 2.0 µA
LT1494H/LT1495H/LT1496H
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage V
S
= 5V ●225 875 µV
V
S
= 3V ●275 975 µV
V
OS
TC Input Offset Voltage Drift (Note 4) ●0.4 3 µV/°C
I
B
Input Bias Current (Note 5) ●3.8 10 nA
V
CM
= 10V (Note 6) ●0.300 2 µA
I
OS
Input Offset Current (Note 5) ●0.3 2 nA
A
VOL
Large-Signal Voltage Gain V
S
= 5V, V
O
= 0.25V to 4.5V, R
L
= 100k ●425 V/mV
V
S
= 3V, V
O
= 0.25V to 2.5V, R
L
= 100k ●217 V/mV
Input Voltage Range ●0.5 36 V
CMRR Common Mode Rejection Ratio V
CM
= 0.5V to 4V, V
S
= 5V ●72 95 dB
V
CM
= 0.5V to 10V, V
S
= 5V ●85 dB
PSRR Power Supply Rejection Ratio V
S
= 2.7V to 12V, V
CM
= V
O
= 0.5V ●86 105 dB
Minimum Operating Supply Voltage ●2.7 V
V
OL
Output Voltage Swing LOW No Load ●70 160 mV
I
SINK
= 100µA●275 550 mV
V
OH
Output Voltage Swing HIGH No Load ●V
+
– 140 V
+
– 45 mV
I
SOURCE
= 100µA●V
+
– 450 V
+
– 225 mV
I
S
Supply Current per Amplifier (Note 6) ●25µA
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 125°C. VS = 5V, 0V; VS = 3V, 0V; VCM = VO =
half supply, unless otherwise noted. (Note 3)
6
LT1494/LT1495/LT1496
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage ●250 675 µV
MS8 Package ●250 775 µV
I
B
Input Bias Current ●250 1700 pA
I
OS
Input Offset Current ●20 170 pA
A
VOL
Large-Signal Voltage Gain V
O
= ±10V, R
L
= 100k ●50 200 V/mV
Input Voltage Range ●–14.8 21 V
CMRR Common Mode Rejection Ratio V
CM
= –14.8V to 14V ●96 114 dB
PSRR Power Supply Rejection Ratio V
S
= ±5V to ±15V ●92 120 dB
V
OL
Output Voltage Swing LOW R
L
= 1M ●–14.83 –14.66 V
R
L
= 100k ●–14.72 –14.44 V
V
OH
Output Voltage Swing HIGH R
L
= 1M ●14.74 14.87 V
R
L
= 100k ●14.54 14.77 V
I
SC
Short-Circuit Current ●0.4 1.1 mA
I
S
Supply Current per Amplifier ●2.0 3.0 µA
The ● denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C, VS = ±15V, VCM = VO = 0V, unless
otherwise noted. (Note 3)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage ●225 625 µV
MS8 Package ●225 725 µV
I
B
Input Bias Current ●250 1200 pA
I
OS
Input Offset Current ●20 120 pA
A
VOL
Large-Signal Voltage Gain V
O
= ±10V, R
L
= 100k ●60 240 V/mV
Input Voltage Range ●–14.8 21 V
CMRR Common Mode Rejection Ratio V
CM
= –14.8V to 14V ●98 120 dB
PSRR Power Supply Rejection Ratio V
S
= ±5V to ±15V ●94 120 dB
V
OL
Output Voltage Swing LOW R
L
= 1M ●–14.84 –14.67 V
R
L
= 100k ●–14.73 –14.46 V
V
OH
Output Voltage Swing HIGH R
L
= 1M ●14.76 14.88 V
R
L
= 100k ●14.58 14.79 V
I
SC
Short-Circuit Current ●0.6 1.3 mA
I
S
Supply Current per Amplifier ●1.6 2.4 µA
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C, VS = ±15V, VCM = VO = 0V, unless
otherwise noted. (Note 3)
ELECTRICAL CHARACTERISTICS
7
LT1494/LT1495/LT1496
LT1494H/LT1495H/LT1496H
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage ●275 1100 µV
I
B
Input Bias Current ●3.8 10 nA
I
OS
Input Offset Current ●0.3 2 nA
A
VOL
Large-Signal Voltage Gain V
O
= ±10V, R
L
= 100k ●21 70 V/mV
Input Voltage Range ●–14.5 21 V
CMRR Common Mode Rejection Ratio V
CM
= –14.5V to 14V ●69 90 dB
PSRR Power Supply Rejection Ratio V
S
= ±5V to ±15V ●89 115 dB
V
OL
Output Voltage Swing LOW R
L
= 1M ●–14.80 –14.4 V
R
L
= 100k ●–14.69 –14.2 V
V
OH
Output Voltage Swing HIGH R
L
= 1M ●14.5 14.85 V
R
L
= 100k ●14.3 14.73 V
I
S
Supply Current per Amplifier ●36µA
ELECTRICAL CHARACTERISTICS
–40°C to 85°C but are not tested or QA sampled at these temperatures.
The LT1494I/LT1495I/LT1496I are guaranteed to meet specified
performance from –40°C to 85°C. The LT1494H/LT1495H/LT1496H are
guaranteed to meet specified performance from –40°C to 125°C.
Note 4: This parameter is not 100% tested.
Note 5: V
S
= 5V limits are guaranteed by correlation to V
S
= 3V and
V
S
= ±15V tests.
Note 6: V
S
= 3V limits are guaranteed by correlation to V
S
= 5V and
V
S
= ±15V tests.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: The LT1494C/LT1495C/LT1496C and LT1494I/LT1495I/LT1496I
are guaranteed functional over the operating temperature range of –40°C
to 85°C. The LT1494H/LT1495H/LT1496H are guaranteed functional over
the operating temperature range of –40°C to 125°C.
Note 3: The LT1494C/LT1495C/LT1496C are guaranteed to meet specified
performance from 0°C to 70°C. The LT1494C/LT1495C/LT1496C are
designed, characterized and expected to meet specified performance from
TYPICAL PERFORMANCE CHARACTERISTICS
UW
INPUT OFFSET VOLTAGE (µV)
–400
0
PERCENT OF UNITS (%)
2
6
8
10
20
14
–200 0100
1495 G01
4
16
18
12
–300 –100 200 300 400
V
S
= 5V, 0V
LT1494/LT1495/
LT1496
5700 OP AMPS
Distribution of Input Offset Voltage
TOTAL SUPPLY VOLTAGE (V)
1
CHANGE IN OFFSET VOLTAGE (µV)
100
150
200
5
1495 G03
50
–50
0
234
T
A
= 85°C
T
A
= –40°C
T
A
= 25°C
TEMPERATURE (°C)
–40 –20
0
SUPPLY CURRENT PER AMPLIFIER (µA)
1.0
2.5
040 60
1495 G02
0.5
2.0
1.5
20 80 100
V
S
= ±15V
V
S
= ±2.5V
Supply Current vs Temperature Minimum Supply Voltage
The ● denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 125°C. VS = ±15V, VCM = VO = half supply,
unless otherwise noted. (Note 3)
8
LT1494/LT1495/LT1496
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Output Saturation Voltage
vs Load Current (Output Low)
LOAD CURRENT (µA)
0.1
10
SATURATION VOLTAGE (mV)
100
1000
101 1000100
1495 G04
V
S
= 5V, 0V
T
A
= 85°C
T
A
= –40°C
T
A
= 25°C
Input Bias Current
vs Common Mode Voltage
COMMON MODE VOLTAGE (V)
0
INPUT BIAS CURRENT (nA)
100
200
300
8
1495 G06
1.5
0.5
–0.5 246
1–1 9
35710
V
S
= 5V, 0V T
A
= 85°C
T
A
= 85°C
T
A
= 25°C
T
A
= –40°C
T
A
= –40°C
T
A
= 25°C
Output Saturation Voltage
vs Load Current (Output High)
LOAD CURRENT (µA)
0.1
10
SATURATION VOLTAGE (mV)
100
1000
101 1000100
1495 G05
V
S
= 5V, 0V
T
A
= 85°C
T
A
= –40°C
T
A
= 25°C
Noise Current Spectrum
FREQUENCY (Hz)
1
0
CURRENT NOISE (fA/√Hz)
20
40
60
80
10 100
1495 G09
100 V
S
= ±2.5V
0.1Hz to 10Hz
Output Voltage Noise
TIME (1s/DIV)
OUTPUT VOLTAGE (2µV/DIV)
1495 G07
V
S
= ±15V
V
CM
= 0V
Gain and Phase Shift
vs Frequency
FREQUENCY (kHz)
0.1
–30
VOLTAGE GAIN (dB)
PHASE SHIFT (DEG)
–20
–10
0
10
50
110
1495 G10
20
30
40
–40
–20
0
20
40
120
60
80
100
PHASE
GAIN
VS = ±2.5V
Noise Voltage Spectrum
FREQUENCY (Hz)
1
0
NOISE VOLTAGE (nV/√Hz)
50
100
150
200
300
10 100
1495 G08
250
V
S
= ±2.5V
Gain Bandwidth and Phase
Margin vs Supply Voltage
SUPPLY VOLTAGE (V)
0
2.0
2.5
3.0
15 25
1495 G11
1.5
1.0
510 20 30
0.5
0
FREQUENCY (kHz)
PHASE MARGIN (DEG)
3.5
40
50
60
30
20
10
0
70
PHASE MARGIN
GBW
CAPACITIVE LOAD (pF)
20
OVERSHOOT (%)
40
50
70
80
10 1000 10000 100000
1495 G12
0100
60
30
10
V
S
= ±2.5V
A
V
= 1
A
V
= 5
A
V
= 10
Capacitive Load Handling
9
LT1494/LT1495/LT1496
TYPICAL PERFORMANCE CHARACTERISTICS
UW
FREQUENCY (kHz)
1
OUTPUT IMPEDANCE (kΩ)
10
100
1000
0.01 1 10
1495 G15
0.1 0.1
A
V
= 10
A
V
= 1
FREQUENCY (kHz)
0.01
40
POWER SUPPLY REJECTION RATIO (dB)
50
60
70
80
0.1 1 10
1495 G14
30
20
10
0
90
100 VS = ±2.5V
POSITIVE
SUPPLY
NEGATIVE
SUPPLY
Power Supply Rejection Ratio
vs Frequency
Common Mode Rejection Ratio
vs Frequency
FREQUENCY (kHz)
0.01
40
COMMON MODE REJECTION RATIO (dB)
50
60
70
80
0.1 1 10
1495 G13
30
20
10
0
90
100 VS = ±2.5V
Warm-Up Drift vs Time
TIME AFTER POWER-UP (SEC)
0
OFFSET VOLTAGE CHANGE (µV)
40
20
30
10
0
–10
–20
–30
– 40 160
1495 G16
40 80 120 20014020 60 100 180
VS = ±15V
VS = ±2.5V
Open-Loop Gain
VS = 5V, 0V
OUTPUT VOLTAGE (V)
0
OFFSET VOLTAGE CHANGE (µV)
–5
0
5
35
1495 G17
–10
–15
–20 12 4
10
15
20
6
VS = 5V, 0V
RL = 1M
RL = 100k
Open-Loop Gain
VS = ±15V
OUTPUT VOLTAGE (V)
–20 –15
OFFSET VOLTAGE CHANGE (µV)
0
40
20
1495 G18
–40
–80 –10 –5 0 5 1510
80
–20
20
–60
60
R
L
= 100k
V
S
= ±15V
R
L
= 1M
Small-Signal Response
VS = ±15V
V
S
= ±15V
R
L
= 1M
C
L
= 100pF
1495 G19
Small-Signal Response
VS = 5V, 0V
V
S
= 5V, 0V
R
L
= 1M
C
L
= 100pF
1495 G20
Large-Signal Response
VS = 5V, 0V
V
S
= 5V, 0V
R
L
= 1M
C
L
= 100pF
1495 G21
Output Impedance vs Frequency
10
LT1494/LT1495/LT1496
APPLICATIONS INFORMATION
WUUU
Start-Up Characteristics
Micropower op amps are sometimes not micropower
during start-up, wreaking havoc on low current supplies.
In the worst case, there may not be enough supply current
available to take the system up to nominal voltages. Figure
1 is a graph of LT1495 supply current vs supply voltage
for the three limit cases of input offset that could occur
during start-up. The circuits are shown in Figure 2. One
circuit creates a positive offset, forcing the output to come
up saturated high. Another circuit creates a negative
offset, forcing the output to come up saturated low, while
the last brings up the output at half supply. In all cases, the
supply current is well behaved. Supply current is highest
with the output forced high, so if one amplifier is unused,
it is best to force the output low or at half supply.
Reverse Battery
The LT1494/LT1495/LT1496 are protected against reverse
battery voltages up to 18V. In the event a reverse battery
condition occurs, the supply current is typically less than
100nA (inputs grounded and outputs open). For typical
single supply applications with ground referred loads and
feedback networks, no other precautions are required. If
the reverse battery condition results in a negative voltage
at either the input pins or output pin, the current into the
pin should be limited by an external resistor to less than
10mA.
Inputs
While the LT1494/LT1495/LT1496 will function normally
with its inputs taken above the positive supply, the com-
mon mode range does not extend beyond approximately
300mV below the negative supply at room temperature.
The device will not be damaged if the inputs are taken lower
than 300mV below the negative supply as long as the cur-
rent out of the pin is limited to less than 10mA. However,
the output phase is not guaranteed and the supply current
will increase.
Output
The graph, Capacitive Load Handling, shows amplifier sta-
bility with the output biased at half supply. If the output is
to be operated within about 100mV of the positive rail, the
allowable load capacitance is less. With this output volt-
age, the worst case occurs at AV = 1 and light loads, where
the load capacitance should be less than 500pF with a 5V
supply and less than 100pF with a 30V supply.
Rail-to-Rail Operation
The simplified schematic, Figure 3, details the circuit
design approach of the LT1494/LT1495/LT1496. The
amplifier topology is a three-stage design consisting of a
rail-to-rail input stage, that continues to operate with the
inputs above the positive rail, a folded cascode second
stage that develops most of the voltage gain, and a rail-to-
rail common emitter stage that provides the current gain.
Figure 1. Start-Up Characteristics
1495 F02
OUTPUT HIGH
V
S
–
+
OUTPUT AT V
S
/2
V
S
–
+
OUTPUT LOW
V
S
–
+
V
S
/2
Figure 2. Circuits for Start-Up Characteristics
SUPPLY VOLTAGE (V)
0
5
4
3
2
1
SUPPLY CURRENT PER AMPLIFIER (µA)
5
1495 F01
01234
OUTPUT HIGH
OUTPUT LOW
OUTPUT V
S
/2
11
LT1494/LT1495/LT1496
APPLICATIONS INFORMATION
WUUU
Figure 3. Simplified Schematic
The input stage is formed by two diff amps Q1-Q2 and Q3-
Q6. For signals with a common mode voltage between VEE
and (VCC – 0.8V), Q1 and Q2 are active. When the input
common mode exceeds (VCC – 0.8V), Q7 turns on,
diverting the current from diff amp Q1-Q2 to current
mirror Q8-Q9. The current from Q8 biases on the other diff
amp consisting of PNP’s Q5-Q6 and NPN’s Q3-Q4. Though
Q5-Q6 are driven from the emitters rather than the base,
the basic diff amp action is the same. When the common
mode voltage is between (VCC – 0.8V) and VCC, devices Q3
and Q4 act as followers, forming a buffer between the
amplifier inputs and the emitters of the Q5-Q6. If the
common mode voltage is taken above VCC, Schottky
diodes D1 and D2 reverse bias and devices Q3 and Q4 then
act as diodes. The diff amp formed by Q5-Q6 operates
normally, however, the input bias current increases to the
emitter current of Q5-Q6, which is typically 180nA. The
graph, Input Bias Current vs Common Mode Voltage
found in the Typical Performance Characteristics section,
shows these transitions at three temperatures.
The collector currents of the two-input pairs are combined
in the second stage consisting of Q11 to Q16, which
furnishes most of the voltage gain. Capacitor C1 sets the
amplifier bandwidth. The output stage is configured for
maximum swing by the use of common emitter output
devices Q21 and Q22. Diodes D4 to D6 and current source
Q15 set the output quiescent current.
+
+
1495 F03
0.5
Q6
Q4 Q16 Q17(V
+
) – 0.8V Q19
Q18 Q22
C1
D1 D2
V+
D3
Q3
Q11
Q2 Q7
IN
–
IN
+
Q10 Q13 Q20
Q21
OUT
Q12
Q14 Q15
Q5
0.5
0.5
0.5
Q8 R1 R2 I
2
+
I
1
D6
D5
D4
D7
Q9
Q1
12
LT1494/LT1495/LT1496
TYPICAL APPLICATIONS N
U
13µA, 0kHz to 10kHz Voltage to Frequency Converter
–
+
1/2
LT1495
–
+
1/2
LT1495
5V
5V
1.2
REFERENCE
LTC1440
0V – 2.5V = 0kHz – 10kHz
SUPPLY CURRENT = 6.2µA QUIESCENT
= 13.3µA AT f = 10kHz
LINEARITY: ±0.03%
PSRR (4.4V TO 36V): 10ppm/V
TEMPERATURE DRIFT: 250ppm/°C
1µF
0.0082µF
1N5712
1N4148
Q1: ZTX-849
*1% METAL FILM
†
POLYSTYRENE
360k
100k
562k*
V
IN
0V TO 2.5V
3.9M
270k
10M*
390Ω
12pF
OUTPUT
0kHz TO 10kHz
3.6M TYP
SELECT FOR 100Hz
AT V
IN
= 0.025V
3.9M*
20M
+
–
+
LTC
®
1440
100pF
†
0.05µF
39k 10M
1495 TA07
Q1
15k
–
+
1/2
LT1495
–
+
1/2
LT1495
10M
1µF
5V
–5V
5V
–5V
φ2
φ1
φ2
φ1
10k
10M
GAIN: 1000
OFFSET: 1µV
DRIFT: 50nV/°C
SUPPLY CURRENT: 5.5µA
BANDWIDTH: 0.2Hz
CLOCK RATE: 4Hz
OUTPUT
10k
1M
1495 TA08
1M
1µF
INPUT
φ1
φ2
0.2µF
–
+
1/2
LTC1441
–
+
1/2
LTC1441
10M
10M
10M
0.047µF
CD4016 QUAD
6µA, AV = 1000, Chopper Stabilized Amplifier
13
LT1494/LT1495/LT1496
PACKAGE DESCRIPTION
U
6th Order 10Hz Elliptic Lowpass Filter Filter Frequency Response
FREQUENCY (Hz)
1
GAIN (dB)
0
–10
–20
–30
–40
–50
–60 1000
LT1495/96 • TA04
10 100
–
+
1/2 LT1495
–
+
1/2 LT1495
200k
100k 10k
10nF
100k
100nF
215k
215k
215k
15nF15nF
30nF
e
in
200k
80.6k
10nF
100k
100nF
169k
169k
169k
15nF15nF
30nF
1495 TA03
V
S
= 5V, 0V
I
S
= 2µA + e
in
/150k
ZEROS AT 50Hz AND 60Hz
OUTPUT
100nF
10k
100nF
TYPICAL APPLICATIONS N
U
MSOP (MS8) 1100
* 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
0.021 ± 0.006
(0.53 ± 0.015)
0° – 6° TYP
SEATING
PLANE
0.007
(0.18)
0.043
(1.10)
MAX
0.009 – 0.015
(0.22 – 0.38) 0.005 ± 0.002
(0.13 ± 0.05)
0.034
(0.86)
REF
0.0256
(0.65)
BSC
12
34
0.193 ± 0.006
(4.90 ± 0.15)
8765
0.118 ± 0.004*
(3.00 ± 0.102)
0.118 ± 0.004**
(3.00 ± 0.102)
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
14
LT1494/LT1495/LT1496
PACKAGE DESCRIPTION
U
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
N8 1098
0.100
(2.54)
BSC
0.065
(1.651)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.130 ± 0.005
(3.302 ± 0.127)
0.020
(0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.125
(3.175)
MIN
12 34
8765
0.255 ± 0.015*
(6.477 ± 0.381)
0.400*
(10.160)
MAX
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
0.016 – 0.050
(0.406 – 1.270)
0.010 – 0.020
(0.254 – 0.508)× 45°
0°– 8° TYP
0.008 – 0.010
(0.203 – 0.254)
SO8 1298
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
TYP
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
1234
0.150 – 0.157**
(3.810 – 3.988)
8765
0.189 – 0.197*
(4.801 – 5.004)
0.228 – 0.244
(5.791 – 6.197)
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
*
**
15
LT1494/LT1495/LT1496
PACKAGE DESCRIPTION
U
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 represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
S Package
14-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
N Package
14-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
1234
0.150 – 0.157**
(3.810 – 3.988)
14 13
0.337 – 0.344*
(8.560 – 8.738)
0.228 – 0.244
(5.791 – 6.197)
12 11 10 9
567
8
0.016 – 0.050
(0.406 – 1.270)
0.010 – 0.020
(0.254 – 0.508)× 45°
0° – 8° TYP
0.008 – 0.010
(0.203 – 0.254)
S14 1298
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
TYP
0.004 – 0.010
(0.101 – 0.254)
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
*
**
N14 1098
0.020
(0.508)
MIN
0.125
(3.175)
MIN
0.130 ± 0.005
(3.302 ± 0.127)
0.045 – 0.065
(1.143 – 1.651)
0.065
(1.651)
TYP
0.018 ± 0.003
(0.457 ± 0.076)
0.100
(2.54)
BSC
0.005
(0.125)
MIN
0.255 ± 0.015*
(6.477 ± 0.381)
0.770*
(19.558)
MAX
31 24567
8910
11
1213
14
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
16
LT1494/LT1495/LT1496
LINEAR TECHNOLOGY CORPORATION 1997
149456fb LT/TP 0801 1.5K REV B • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
●
(408) 432-1900
FAX: (408) 434-0507
●
TELEX: 499-3977
●
www.linear.com
Battery Current Monitor 0nA to 200nA Current Meter
TYPICAL APPLICATIONS N
U
RELATED PARTS
–
+
–
+
1495 TA05
R
SENSE
0.1Ω
I
L
CHARGE
R
A
2N3904
V
O
= I
L
R
SENSE
FOR R
A
= 1k, R
B
= 10k
= 1V/A
CHARGE
OUT
DISCHARGE
OUT
DISCHARGE
2N3904
R
A
R
A
R
A
R
B
R
B
R
A
V
O
I
L
R
B
A1
1/2 LT1495
5V 12V
A2
1/2 LT1495
()
–
+
–
+
µA
1495 TA06
1/2
LT1495
1/2
LT1495
100pF
R1
10M
R2
9k
1.5V
1.5V
R3
2k
FULL-SCALE
ADJUST
I
S
= 3µA WHEN I
IN
= 0
NO ON/OFF SWITCH
REQUIRED
0µA TO
200µA
R4
10k
INPUT
CURRENT
High Side Current Sense
PART NUMBER DESCRIPTION COMMENTS
LTC®1440/41/42 Micropower Single/Dual Comparators with 1% Reference LTC1440: Single, LTC1441/42: Dual
LTC1443/44/45 Micropower Quad Comparators with 1% Reference LTC1443: 1.182 Reference
LTC1444/45: 1.221V Reference and Adjustable Hysteresis
LT1466/LT1467 75µA Dual/Quad Rail-to-Rail Input and Output Op Amps 390µV V
OS(MAX)
, Gain Bandwidth = 120kHz
LT1490A/LT1491A 50µA Dual/Quad Rail-to-Rail Input and Output Op Amps 950µV V
OS(MAX)
, Gain Bandwidth = 200kHz
LTC1540 Nanopower Single Comparator with 1% Reference 350nA Supply Current
LT1636 Single Over-The-Top Micropower, 225µV V
OS(MAX)
, I
S
= 55µA (MAX), Gain-Bandwidth = 200kHz
Rail-to-Rail Input and Output Op Amp Shutdown Pin, MSOP
LT1672/LT1673/LT1674 2µA MAX, A
V
≥ 5 Single/Dual/Quad Over-The-Top Precision Decompensated Version of the LT1494/LT1495/LT1496
Rail-to-Rail Input and Output Op Amps A
V
≥ 5, Gain-Bandwidth = 12kHz
LT2078/LT2079 55µA Dual/Quad Single Supply Op Amps 120µV V
OS(MAX)
, Gain Bandwidth = 200kHz
LT2178/LT2179 17µA Dual/Quad Single Supply Op Amps 120µV V
OS(MAX)
, Gain Bandwidth = 60kHz
LT1782 Micropower, Over-The-Top, SOT-23, Rail-to-Rail SOT-23, 800µV V
OS(MAX)
, I
S
= 55µA (Max),
Input and Output Op Amp Gain-Bandwidth = 200kHz, Shutdown Pin
LT1783 1.2MHz, Over-The-Top, Micropower, Rail-to-Rail SOT-23, 800µV V
OS(MAX)
, I
S
= 300µA (Max),
Input and Output Op Amp in SOT-23 Gain-Bandwidth = 1.2MHz, Shutdown Pin
+
–
LT1494
R
A
1k
R
SENSE
1Ω
LOAD I
L
V
S
= 2.7V TO 36V
1495 TA09
R
B
10k
+
_
V
O
( )
R
B
R
A
V
O
= I
L
R
S
FOR R
A
= 1k, R
B
= 10k, R
S
= 1Ω
= 10 V/A
OUTPUT OFFSET ≈ I
S
• R
B
≈ 10mV
OUTPUT CLIPS AT V
S
– 2.4V
V
O
I
L