Transcript
LT1097 Low Cost, Low Power Precision Op Amp
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DESCRIPTION
FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■
Offset Voltage 50µV Max Offset Voltage Drift 1µV/°C Max Bias Current 250pA Max Offset Current 250pA Max Bias and Offset Current Drift 4pA/°C Max Supply Current 560µA Max 0.1Hz to 10Hz Noise 0.5µVp-p, 2.2pAp-p CMRR 115dB Min Voltage Gain 117dB Min PSRR 114dB Min Guaranteed Operation on Two NiCad Batteries
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■ ■ ■ ■ ■
Replaces OP-07/OP-77/OP-97/OP-177/AD707/ LT1001 with Improved Price/Performance High Impedance Difference Amplifiers Logarithmic Amplifiers (Wide Dynamic Range) Thermocouple Amplifiers Precision Instrumentation Active Filters (with Small Capacitors)
LT®1097 achieves a new standard in combining low price and outstanding precision performance. On all operational amplifier data sheets, the specifications listed on the front page are for highly selected, expensive grades, while the specs for the low cost grades are buried deep in the data sheet. The LT1097 does not have any selected grades, the outstanding specifications shown in the Features section are for its only grade. The design effort of the LT1097 concentrated on optimizing the performance of all precision specs—at only 350µA of supply current. Typical values are 10µV offset voltage, 40pA bias and offset currents, 0.2µV/°C and 0.4pA/°C drift. Common mode and power supply rejections, voltage gain are typically in excess of 128dB. All parameters that are important for precision, low power op amps have been optimized. Consequently, using the LT1097 error budget calculations in most applications is unnecessary. , LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATION Input Offset Voltage Distribution
Saturated Standard Cell Amplifier 9V
50
2N3609
+
7 LT1097
2
+ 1.018235V SATURATED STANDARD CELL #101 EPPLEY LABS NEWPORT, R. I.
R1 20k
–
40
6
OUT = 1.1V TO 8.0V AS 1.8k ≤ R2 ≤ 135k
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PERCENT OF UNITS
3
30
6,500 UNITS IN SO PACKAGE 6,680 UNITS IN PLASTIC VS = ±15V DIP TA = 25°C 13,180 UNITS TESTED
20
10
R2 THE TYPICAL 40pA BIAS CURRENT OF THE LT1097 WILL DEGRADE THE STANDARD CELL BY ONLY 1ppm/YEAR. NOISE IS A FRACTION OF A ppm. UNPROTECTED GATE MOSFET ISOLATES STANDARD CELL ON POWER DOWN.
0 –50 –40 –30 –20 –10 0 10 20 30 40 50 INPUT OFFSET VOLTAGE (µV) LT1097 • G01
LT1097•TA01
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LT1097
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ABSOLUTE MAXIMUM RATINGS Supply Voltage ...................................................... ±20V Differential Input Current (Note 1) ...................... ±10mA Input Voltage ......................................................... ±20V Output Short Circuit Duration .......................... Indefinite
Operating Temperature Range .................–40°C to 85°C Storage Temperature Range ..................–65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C
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PACKAGE/ORDER INFORMATION TOP VIEW VOS TRIM 1
8
VOS TRIM
–IN 2
7
V+
+IN 3
6
OUT
V– 4
5
OVER COMP
ORDER PART NUMBER LT1097CN8
TOP VIEW VOS TRIM 1
8
VOS TRIM
–IN 2
7
V+
+IN 3
6
OUT
V– 4
5
OVER COMP
N8 PACKAGE 8-LEAD PLASTIC DIP
LT1097S8
S8 PACKAGE 8-LEAD PLASTIC SO
ELECTRICAL CHARACTERISTICS
VS = ±15V, VCM = 0V, TA = 25°C, unless otherwise noted.
CONDITIONS
MIN
LT1097CN8 TYP MAX
SYMBOL
PARAMETER
VOS
Input Offset Voltage
10
Long Term Input Offset Voltage Stability
0.3
∆VOS ∆TIME
ORDER PART NUMBER
MIN
50
LT1097S8 TYP
MAX
10
60
UNITS µV µV/Mo
0.3
IOS
Input Offset Current
40
250
60
350
pA
IB
Input Bias Current
±40
±250
±50
±350
pA
en
Input Noise Voltage
0.1Hz to 10Hz
0.5
0.5
µVp-p
Input Noise Voltage Density
fO = 10Hz fO = 1000Hz
16 14
16 14
nV/√Hz nV/√Hz
Input Noise Current
0.1Hz to 10Hz
2.2
2.4
pAp-p
Input Noise Current Density
fO = 10Hz fO = 1000Hz
0.03 0.008
0.035 0.008
pA/√Hz pA/√Hz
Input Resistance Differential Mode Common Mode
(Note 2)
in
Input Voltage Range CMRR
Common Mode Rejection Ratio
VCM = ±13.5V
30
80 1012
25
70 8•1011
MΩ Ω
±13.5
±14.3
±13.5
±14.3
V
115
130
115
130
dB
PSRR
Power Supply Rejection Ratio
VS = ±1.2V to ±20V
114
130
114
130
dB
AVOL
Large Signal Voltage Gain
VO = ±12V, RL = 10k VO = ±10V, RL = 2k
700 250
2500 1000
700 250
2500 1000
V/mV V/mV
VOUT
Output Voltage Swing
RL = 10k RL = 2k
±13 ±11.5
±13.8 ±13
±13 ±11.5
±13.8 ±13
V V
SR
Slew Rate
0.1
0.2
0.1
0.2
V/µs
GBW
Gain Bandwidth Product
700
kHz
IS
Supply Current
2
700 350
Offset Adjustment Range
RPOT = 10k, Wiper to V+
Minimum Supply Voltage
(Note 3)
560
350
±600 ±1.2
—
±1.2
560
µA
±600
µV
—
V
LT1097
ELECTRICAL CHARACTERISTICS
VS = ±15V, VCM = 0V, 0°C ≤ TA ≤ 70°C, unless otherwise noted. LT1097S8 TYP
MAX
UNITS
100
20
130
µV
0.2
1
0.2
1.4
µV/°C
●
60
430
75
570
pA
Average Temperature Coefficient of (Note 4) Input Offset Current
●
0.4
4
0.5
5
Input Bias Current
●
±60
±430
±75
±570
Average Temperature Coefficient of (Note 4) Input Bias Current
●
0.4
4
0.5
5
PARAMETER
VOS
Input Offset Voltage
●
20
Average Temperature Coefficient of (Note 4) Input Offset Voltage
●
Input Offset Current
IOS
IB
CONDITIONS
MIN
LT1097CN8 TYP MAX
SYMBOL
MIN
pA/°C pA pA/°C
AVOL
Large Signal Voltage Gain
VOUT = ±12V, RL ≥ 10k VOUT = ±10V, RL ≥ 2k
● ●
450 180
2000 800
450 180
2000 800
V/mV V/mV
CMRR
Common Mode Rejection Ratio
VCM = ±13.5V
●
112
128
112
128
dB
PSRR
Power Supply Rejection Ratio
VS = ±1.3V to ±20V
●
111
128
111
128
dB
●
±13.5
±14.2
±13.5
±14.2
V
●
±13
±13.7
±13
±13.7
Input Voltage Range VOUT
Output Voltage Swing
IS
Supply Current
RL = 10k
380
●
ELECTRICAL CHARACTERISTICS
V 700
µA
LT1097S8 TYP
MAX
UNITS
130
30
170
µV
0.3
1.2
0.3
1.6
µV/°C
●
70
600
85
750
pA
Average Temperature Coefficient of Input Offset Current
●
0.5
5
0.6
6
Input Bias Current
●
±70
±600
±85
±750
Average Temperature Coefficient of Input Bias Current
●
0.5
5
0.6
6
CONDITIONS
MIN
LT1097CN8 TYP MAX
PARAMETER
VOS
Input Offset Voltage
●
25
Average Temperature Coefficient of Input Offset Voltage
●
Input Offset Current
IB
380
VS = ±15V, VCM = 0V, –40°C ≤ TA ≤ 85°C, unless otherwise noted. (Note 5)
SYMBOL
IOS
700
MIN
pA/°C pA pA/°C
AVOL
Large Signal Voltage Gain
VOUT = ±12V, RL ≥ 10k VOUT = ±10V, RL ≥ 2k
● ●
300
1700 700
300
1700 700
V/mV V/mV
CMRR
Common Mode Rejection Ratio
VCM = ±13.5V
●
108
127
108
127
dB
PSRR
Power Supply Rejection Ratio
VS = ±1.5V to ±20V
●
108
127
108
127
dB
●
±13.5
±14
±13.5
±14
V
●
±13
±13.6
±13
±13.6
Input Voltage Range VOUT
Output Voltage Swing
IS
Supply Current
RL = 10k
The ● denotes specifications which apply over the full operating temperature range. Note 1: Differential input voltages greater than 1V will cause excessive current to flow through the input protection diodes unless limiting resistance is used. Note 2: This parameter is guaranteed by design and is not tested.
●
400
800
400
V 800
µA
Note 3: Power supply rejection ratio is measured at the minimum supply voltage. Note 4: This parameter is not 100% tested. Note 5: The LT1097 is designed, characterized and expected to meet these extended temperature limits, but is not tested at –40°C and 85°C. Guaranteed I grade parts are available; consult factory.
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LT1097 U W
TYPICAL PERFORMANCE CHARACTERISTICS Distribution to Offset Voltage Drift with Temperature 50
VS = ±15V 240 UNITS TESTED IN N8 PACKAGES FROM SIX RUNS
PERCENT OF UNITS
40
30
20
10
0 –1.5 –1.2 –0.9 –0.6 –0.3 0 0.3 0.6 0.9 1.2 1.5 OFFSET VOLTAGE DRIFT WITH TEMPERATURE (µV/°C) LT1097 • G02
Minimum Supply Voltage, Common Mode Range and Voltage Swing at VMIN
INPUT BIAS CURRENT (pA)
200
100
UNDERCANCELLED UNIT
0
–100
OVERCANCELLED UNIT
–200
–300 –50
–25
0 25 50 TEMPERATURE (°C)
75
V+
±1.4
V+ –0.2
±1.2
V+ –0.4 V+ –0.6
±1.0 CM RANGE
±0.8
V+ –0.8
SWING
V– +0.8
SWING
RL = 10k V– +0.6
CM RANGE
V– +0.4 V– +0.2
100
V– –40
–10
20 50 TEMPERATURE (°C)
80
1097 • G03
Input Bias Current Over Common Mode Range 120
VS = ±15V TA = 25°C
80 INPUT BIAS CURRENT (pA)
CHANGE IN OFFSET VOLTAGE (µV)
5
3
2 PLASTIC-IN-LINE PACKAGE PLASTIC (N) OR SO (S)
1
0 1 2 3 4 TIME AFTER POWER ON (MINUTES)
5
1097 • G05
4
VS = ±15V TA = 25°C DEVICE WITH POSITIVE INPUT CURRENT
40 RIN CM = 1012Ω 0
DEVICE WITH NEGATIVE INPUT CURRENT
–40 –
–80
0
110 1097 • G04
Warm-Up Drift
4
MINIMUM SUPPLY VOLTAGE, VMIN (V)
COMMON MODE RANGE OR OUTPUT SWING (V)
Input Bias Current vs Temperature
–120 –15
VCM
IB
+
–10 –5 0 5 10 COMMON MODE INPUT VOLTAGE
15
1097 • G06
LT1097 U W
TYPICAL PERFORMANCE CHARACTERISTICS Output Short Circuit Current vs Time
SHORT CIRCUIT CURRENT (mA) SINKING SOURCING
20 15 10 5
VS = ±15V TA = 25°C
0 –5
–10 –15 –20 0
1 2 TIME FROM OUTPUT SHORT (MINUTES)
3
1097 • G07
0.1Hz to 10Hz Noise
0.01Hz to 10Hz Noise
0
2
4 6 TIME (SECONDS)
8
VS = ±1.2V TO ±20V TA = 25°C
0.4µV
NOISE VOLTAGE (0.4µV/DIV)
NOISE VOLTAGE (0.4µV/DIV)
VS = ±1.2V TO ±20V TA = 25°C
10
0
20
40 60 TIME (SECONDS)
80
1097 • G08
1097 • G09
Voltage Gain
Noise Spectrum 1000
–30 TA = 25°C VS = ±1.2V TO ±20V
100
CURRENT NOISE
VOLTAGE NOISE 10
1/f CORNER 2.5Hz
1/f CORNER 140Hz
1 1
10 100 FREQUENCY (Hz)
1000 1097 • G10
CHANGE IN OFFSET VOLTAGE (µV)
VOLTAGE NOISE DENSITY (nV√Hz) CURRENT NOISE DENSITY (fA√Hz)
100
–20
Vs = ±15 V TA = 25°C
–10 RL = 10k 0 10
RL = 10k RL = 2k
RL = 2k
20 30 –15
–10
–5 0 5 OUTPUT VOLTAGE (V)
10
15
1097 • G11
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LT1097 U W
TYPICAL PERFORMANCE CHARACTERISTICS Voltage Gain vs Frequency 140 VS = ±15V TA = 25°C
120 VOLTAGE GAIN (dB)
100 80 60 40 20 0 –20 0.01 0.1
1
10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 1097 • G12
Common Mode Rejection vs Frequency
Gain, Phase Shift vs Frequency
PHASE
120
GAIN (dB)
GAIN 20
140
10
160
0
180 PHASE MARGIN = 70°C 0.1 1 FREQUENCY (MHz)
10
PHASE SHIFT (DEGREES)
30
–10 0.01
140
100
VS = ±15V TA = 25°C
COMMON MODE REJCTION RATIO (dB)
40
VS = ±15V TA = 25°C
120 100 80 60 40 20 0
200
1
10
100 1k 10k FREQUENCY (Hz)
100k
1097 • G13
1097 • G14
Slew Rate, Gain Bandwidth Product vs Overcompensation Capacitor
Power Supply Rejection vs Frequency 1
SLEW RATE (V/µs)
120 100
NEGATIVE SUPPLY 80 POSITIVE SUPPLY 60
SLEW
0.1
GBW
0.01
100
10
40
VS = ±15V TA = 25°C 0.001 1
10
100 1k 10k 100k FREQUENCY (Hz)
1M
1097 • G15
6
1000
VS = ±15V TA = 25°C
1
1 10 100 1000 10000 OVERCOMPENSATION CAPACITOR (pF) 1097 • G16
GAIN BANDWIDTH PRODUCT (kHz)
POWER SUPPLY REJECTION RATIO (dB)
140
20 0.1
1M
LT1097 U W
TYPICAL PERFORMANCE CHARACTERISTICS Large Signal Transient Response
2V/DIV
20mV/DIV
Small Signal Transient Response
AV = 1, CLOAD = 100pF, 5µs/DIV
1097 G17
AV = 1, 20µs/DIV
1097 G18
Capacitive Load Handling 70 TA = 25°C VS = ±15V CS: PIN 5 TO GROUND
60
OVERSHOOT (%)
50 AV = 1 CS = 0
40 30
AV = 1 CS = 200pF
20 10
AV = 10 CS = 0
0 10
100 1000 CAPACITIVE LOAD (pF)
10,000 1097 G19
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LT1097 W W SCHEMATIC DIAGRAM TRIM 1
TRIM 8
V+
5 OVER COMP
7 800Ω
800Ω
30k
30k
20µA 35µA
80µA
1.3k
30pF
Q19
Q22 1.5k
2.5k
1.5k Q33 Q25
Q21
Q27
Q6
Q5
Q29 S
Q8
Q24
Q4
40Ω
Q7
– IN
S
S Q1
2
Q2
100Ω
3k
Q13 S
OUT 6
Q11 Q23
1.5k
40Ω
Q3 Q20 50k
Q28
J1
1.5k
Q26
Q9
Q32
Q18
Q12 Q16 +IN
Q10 Q17
3 3.7k 15µA
80µA
Q30
5µA
Q31 Q14
Q15
5µA 3.7k
3.7k
16k
40Ω
330Ω
V– 4 Q1–Q4 ARE SUPERGAIN TRANSISTORS
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1097 BD
LT1097
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APPLICATIONS INFORMATION The LT1097 is pin compatible to and directly replaces such precision op amps as the OP-07, OP-77, AD707, OP-97, OP177, LM607 and LT1001 with improved price/performance. Compatibility includes externally nulling the offset voltage, as all of the above devices are trimmed with a potentiometer between Pin 1 and Pin 8 and the wiper tied to V+. The simple difference amplifier can be used to illustrate the all-around excellence of the LT1097. The 50k input resistance is selected to be large enough compared to input signal source resistance. Simultaneously, the 50k resistors should not dominate the precision and noise error budget. Assuming perfect matching between the four resistors, the following table summarizes the input ±27V Common Mode Range Difference Amplifier
referred performance obtained using the LT1097 and other popular, low cost precision op amps. Input offset voltage can be adjusted over a ±600µV range with a 10k potentiometer. The LT1097 is internally compensated for unity gain stability. As shown on the Capacitive Load Handling plot, the LT1097 is stable with any capacitive load. However, the overcompensation capacitor, CS, can be used to reduce overshoot with heavy capacitive loads, to narrow noise bandwidth or to stabilize circuits with gain in the feedback loop.
Frequency Compensation and Optional Offset Nulling
50k 15V 50k –IN 50k +IN
2
–
3
50k
+
1 2
7 LT1097
V+
10k POT
6
–
8 LT1097
OUT
3
4
+ 4
–15V
7
6
OUT
5 CS
V– LT1097•F02 LT1097•F01
Guaranteed Perfomance, VS = ±15V, TA = 25°C PARAMETER
LT1097CN8
OP-77GP
AD707JN
OP-177GP
OP-97FP
Error Terms VOS Max IOS Max•25k Gain Min, 10V Out CMRR, Min, ±25V In PSRR, Min, VS = ±15V ±10%
UNITS
50 6 14 22 6
100 70 5 20 9
90 50 3 13 9
60 70 5 22 9
75 4 50 39 9
µV µV µV µV µV
Sum of All Error Terms
98
204
165
166
177
µV
0.1Hz to 10Hz Noise Voltage Noise Current Noise•50k Resistor Noise
0.5 0.11 0.55
0.38 0.75 0.55
0.23 0.7 0.55
0.38 0.75 0.55
0.5 0.1 0.55
µVp-p Typ µVp-p Typ µVp-p Typ
RMS sum
0.75
1
0.92
1
0.75
µVp-p
Drift with Temp TCVOS Max TCIOS Max•25k
1 0.1
1.2 2.1
1 1
1.2 2.1
2 0.2
µV/°C µV/°C
Sum of Drift Terms
1.1
3.3
2
3.3
2.2
µV/°C
Supply Current Max
0.56
2
3
2
0.6
mA
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LT1097
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APPLICATIONS INFORMATION The availability of the compensation terminal permits the use of feedforward frequency compensation to enhance slew rate. The voltage follower feedforward scheme bypasses the amplifier’s gain stages and slews at nearly 10V/µs. The inputs of the LT1097 are protected with back-to-back diodes. In the voltage follower configuration, when the input is driven by a fast, large signal pulse (>1V), the input
Follower Feedforward Compensation
protection diodes effectively short the output to the input during slewing, and a current, limited only by the output short circuit protection will flow through the diodes. The use of a feedback resistor, as shown in the voltage follower feedforward diagram, is recommended because this resistor keeps the current below the short circuit limit, resulting in faster recovery and settling of the output.
Pulse Response of Feedforward Compensation
Test Circuit for Offset Voltage and its Drift with Temperature
50pF
50k* 15V
10k
5k IN
5V/DIV
2
– LT1097
3
2
+
6
100Ω*
OUT
5 50k* 1097 G20
5µs/DIV
7 LT1097
3
0.01µF
+
6
VO
4 –15V
VO = 1000VOS *RESISTORS MUST HAVE LOW THERMOELECTRIC POTENTIAL
LT1097•F03
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TYPICAL APPLICATIO
Low Power Comparator with <10µV Hysteresis 5V 330k
7 10k +IN 10k –IN
2
1 LT1097
3
+
1k
100k OUT
–
620k 6
2N3904 100k
4 –5V
10
–
LT1097•TA02
LT1097•F04
LT1097
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PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted. 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)
0.065 (1.651) TYP
0.009 – 0.015 (0.229 – 0.381)
(
+0.035 0.325 –0.015 8.255
+0.889 –0.381
0.130 ± 0.005 (3.302 ± 0.127)
0.045 – 0.065 (1.143 – 1.651)
)
0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1197
0.100 ± 0.010 (2.540 ± 0.254)
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
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
5
6
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)
2
3
4 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)
*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
0.050 (1.270) TYP
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SO8 0996
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LT1097
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TYPICAL APPLICATIO
Input Amplifier for 4 1/2 Digit Voltmeter
0.1V
15V IN
2
0.1V 100k 5%
1V
–
7
3
4
+ 5
9M 10V
1V
6
LT1097
9k*
10V
1k*
1000V
100V
–5V
1000pF
900k 100V
*RATIO MATCH ±0.01%
TO 1V FULL SCALE ANALOG DIGITAL CONVERTER
90k 1000V FN507 10k ALLEN BRADLEY DECADE VOLTAGE DIVIDER
THIS APPLICATION REQUIRES LOW BIAS CURRENT AND OFFSET VOLTAGE, LOW NOISE, AND LOW DRIFT WITH TIME AND TEMPERATURE. LT1097•TA03
RELATED PARTS PART NUMBER
DESCRIPTION
COMMENTS
LT1490/LT1491
Dual/Quad General Purpose Micropower Rail-to-Rail Op Amps
Over-The-TopTM Inputs, 50µA Supply Current Per Amplifier, 2V to 44V Supply Range, 180kHz GBW
LT1492/LT1493
Dual/Quad 5MHz Low Power Single Supply Op Amps
180µV VOS Max, 3V/µs Slew Rate, 550µA Supply Per Amplifier
LT1077
Single Micropower Low VOS Op Amp
60µV VOS Max, 68µA Supply Current, 230kHz GBW, Optimized for 5V Supplies
Over-The-Top is a trademark of Linear Technology Corporation.
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Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417● (408) 432-1900 FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com
1097fas sn1097 LT/TP 0398 2K REV A • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1989
