LTC1051/LTC1053
Dual/Quad Precision
Zero-Drift Operational Amplifiers
With Internal Capacitors
DESCRIPTIO
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FEATURES
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Dual/Quad Low Cost Precision Op Amp
No External Components Required
Maximum Offset Voltage: 5µV
Maximum Offset Voltage Drift: 0.05µV/°C
Low Noise 1.5µVP-P (0.1Hz to 10Hz)
Minimum Voltage Gain: 120dB
Minimum PSRR: 120dB
Minimum CMRR: 114dB
Low Supply Current: 1mA/Op Amp
Single Supply Operation: 4.75V to 16V
Input Common Mode Range Includes Ground
Output Swings to Ground
Typical Overload Recovery Time: 3ms
Pin Compatible with Industry Standard Dual and
Quad Op Amps
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APPLICATIO S
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The LTC®1051/LTC1053 are high performance, low cost
dual/quad zero-drift operational amplifiers. The unique
achievement of the LTC1051/LTC1053 is that they integrate
on chip the sample-and-hold capacitors usually required
externally by other chopper amplifiers. Further, the
LTC1051/LTC1053 offer better combined overall DC and
AC performance than is available from other chopper
stabilized amplifiers with or without internal sample/hold
capacitors.
The LTC1051/LTC1053 have an offset voltage of 0.5µV,
drift of 0.01µV/°C, DC to 10Hz, input noise voltage typically
1.5µVP-P and typical voltage gain of 140dB. The slew rate
of 4V/µs and gain bandwidth product of 2.5MHz are
achieved with only 1mA of supply current per op amp.
Overload recover times from positive and negative
saturation conditions are 1.5ms and 3ms respectively,
about a 100 or more times improvement over chopper
amplifiers using external capacitors.
Thermocouple Amplifiers
Electronic Scales
Medical Instrumentation
Strain Gauge Amplifiers
High Resolution Data Acquisition
DC Accurate R C Active Filters
, LTC and LT are registered trademarks of Linear Technology Corporation.
The LTC1051 is available in an 8-lead standard plastic
dual-in-line package as well as a 16-pin SW package. The
LTC1053 is available in a standard 14-pin plastic package
and an 18-pin SO. The LTC1051/LTC1053 are plug in
replacements for most standard dual/quad op amps with
improved performance.
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TYPICAL APPLICATIO
High Performance Low Cost Instrumentation Amplifier
LTC1051 Noise Spectrum
120
5V
R2
2
VIN
3
–
8
1/2
LTC1051
1
R1
6
+
R1 = 499Ω, 0.1%
R2 = 100k, 0.1%
GAIN = 201
MEASURED CMRR ~ 120dB AT DC
MEASURED INPUT VOS 3µV
MEASURED INPUT NOISE 2µVP-P (DC – 10Hz)
VIN
5
–
1/2
LTC1051
+
7
4
– 5V
VOLTAGE NOISE DENSITY (nV√Hz)
R2
R1
100
80
60
40
20
1051/53 TA01a
10
100
1k
FREQUENCY (Hz)
10k
1051/53 TA01b
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LTC1051/LTC1053
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ABSOLUTE
RATI GS
(Note 1)
Total Supply Voltage (V + to V –) ............................ 16.5V
Input Voltage ........................ (V + + 0.3V) to (V – – 0.3V)
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature Range
LTC1051M, LTC1051AM (OBSOLETE) .. –55°C to 125°C
LTC1051C/LTC1053C ......................... – 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 I FOR ATIO
TOP VIEW
OUT A 1
8
V+
– IN A 2
7
OUT B
+IN A 3
6
–IN B
V– 4
5
+IN B
N8 PACKAGE
8-LEAD PDIP
TJMAX = 150°C, θJA = 110°C/W
J8 PACKAGE
8-LEAD CERDIP
OBSOLETE PACKAGE
ORDER PART
NUMBER
ORDER PART
NUMBER
TOP VIEW
LTC1051CN8
LTC1051MJ8
LTC1051CJ8
LTC1051AMJ8
LTC1051ACJ8
OUT A
1
14 OUT D
– IN A
2
13 – IN D
+IN A
3
12 +IN D
V+
4
11 V –
+IN B
5
10 +IN C
– IN B
6
9
– IN C
OUT B
7
8
OUT C
LTC1053CN
N PACKAGE
14-LEAD PDIP
TJMAX = 150°C, θJA = 65°C/W
Consider the N8 Package as an Alternate Source
TOP VIEW
ORDER PART
NUMBER
ORDER PART
NUMBER
TOP VIEW
NC 1
18 NC
NC 1
16 NC
NC 2
15 NC
OUT A 2
17 OUT D
OUT A 3
14 V +
–IN A 3
16 –IN D
+IN A 4
15 +IN D
LTC1051CSW
–IN A 4
13 OUT B
+IN A 5
12 –IN B
V+ 5
V– 6
11 +IN B
+IN B 6
13 +IN C
NC 7
10 NC
–IN B 7
12 –IN C
NC 8
9
OUT B 8
11 OUT C
NC
NC 9
SW PACKAGE
16-LEAD PLASTIC SO
LTC1053CSW
14 V –
10 NC
SW PACKAGE
18-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 90°C/W
TJMAX = 150°C, θJA = 85°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = ±5V unless otherwise noted.
PARAMETER
LTC1051/LTC1053
MIN
TYP
MAX
CONDITIONS
Input Offset Voltage
Average Input Offset Drift
●
Long Term Offset Drift
LTC1051C/LTC1053C
Input Offset Current
±0.5
±5
±0.0
±0.05
±0.0
±0.05
RS = 100Ω, DC to 10Hz
RS = 100Ω, DC to 1Hz
50
UNITS
µV
µV/°C
nV/√Mo
±15
±65
±135
±15
±50
±100
pA
pA
±30
±125
±175
±30
±100
±150
pA
pA
1.5
0.4
2
●
Input Noise Voltage (Note 2)
MAX
±5
●
(All Grades)
LTC1051A
TYP
±0.5
50
Input Bias Current
MIN
1.5
0.4
µVP-P
µVP-P
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LTC1051/LTC1053
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VS = ±5V unless otherwise noted.
PARAMETER
CONDITIONS
Input Noise Current
f = 10Hz
Common Mode Rejection Ratio, CMRR
VCM
= V–
LTC1051/LTC1053
MIN
TYP
MAX
MIN
2.2
to 2.7V
●
106
100
130
114
110
LTC1051A
TYP
MAX
UNITS
2.2
fA/√Hz
130
dB
dB
Differential CMRR
LTC1051, LTC1053 (Note 3)
VCM = V – to 2.7V
Power Supply Rejection Ratio
VS = ±2.375V to ±8V
●
116
140
120
140
dB
Large Signal Voltage Gain
RL = 10k, VOUT = ±4V
●
116
160
120
160
dB
Maximum Output Voltage Swing
RL = 10k
RL = 100k
●
±4.5
±4.5
±4.85
±4.95
±4.7
±4.85
±4.95
V
V
Slew Rate
RL = 10k, CL = 50pF
112
Gain Bandwidth Product
Supply Current/Op Amp
112
4
4
V/µs
2.5
2.5
MHz
No Load
1
●
Internal Sampling Frequency
dB
2
2.5
1
3.3
2
2.5
mA
mA
3.3
kHz
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VS = ±5V unless otherwise noted.VS = 5V, GND unless otherwise noted.
PARAMETER
CONDITIONS
MIN
LTC1051A/LTC1051/LTC1053
TYP
MAX
UNITS
Input Offset Voltage
±0.5
±5
Input Offset Drift
±0.01
±0.05
Input Bias Current
±10
±50
pA
Input Offset Current
±20
±80
pA
Input Noise Voltage
DC to 10Hz
Supply Current/Op Amp
No Load
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: For guaranteed noise specification contact LTC Marketing.
1.8
●
µV
µV/°C
µVP-P
1.5
mA
Note 3: Differential CMRR for the LTC1053 is measured between
amplifiers A and D, and amplifiers B and C.
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LTC1051/LTC1053
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TYPICAL PERFOR A CE CHARACTERISTICS
Common Mode Input Range vs
Supply Voltage
Sampling Frequency vs Supply
Voltage
4.0
SAMPLING FREQUENCY, fS (kHz)
COMMON MODE RANGE (V)
6
4
2
0
–2
VCM = V –
–4
TA = 25°C
5
SAMPLING FREQUENCY, fS (kHz)
8
Sampling Frequency vs
Temperature
3.5
3.0
2.5
–6
0
1
2
3
4
5
6
SUPPLY VOLTAGE (±V)
7
2.0
8
4
14
16
6
8
10
12
TOTAL SUPPLY VOLTAGE, V + TO V – (V)
2
–50
1.50
TA = 25°C
0.25
1.4
VOLTAGE GAIN (dB)
SUPPLY CURRENT, IS (mA)
SUPPLY CURRENT, IS (mA)
0.50
1.2
1.0
0.8
0.6
14
8
10
12
6
TOTAL SUPPLY VOLTAGE V + TO V – (V)
0
–50
16
50
25
0
75 100
–25
AMBIENT TEMPERATURE, TA (°C)
1051/53 G04
4
CMRR (dB)
4
14
16
8
10
12
6
TOTAL SUPPLY VOLTAGE, V + TO V – (V)
1051/53 G07
0
180
– 20
200
1k
10k
100k
FREQUENCY (Hz)
220
10M
1M
1051/53 G06
Gain/Phase vs Frequency
160
120
140
100
120
80
– 60
VS = ±2.5V
CL = 100pF – 80
RL ≥ 1k
TA = 25°C –100
60
–120
40
–140
20
–160
0
–180
– 20
–200
100
80
60
40
ISINK
160
VS = ±5V
TA = 25°C
AC COMMON MODE IN = 0.5VP-P
20
0
1
10
100
1k
FREQUENCY (Hz)
10k
100k
1051/53 G08
– 40
100
1k
10k
100k
FREQUENCY (Hz)
1M
PHASE SHIFT (DEGREES)
ISOURCE
2
VOUT = V +
20
– 40
100
125
VOLTAGE GAIN (dB)
VOUT = V –
– 20
140
CMRR vs Frequency
6
– 10
40
1051/53 G05
Output Short-Circuit Current vs
Supply Voltage
0
120
0.4
0.2
4
60
100
1.6
PHASE SHIFT (DEGREES)
0.75
80
60
VS = ±5V
CL = 100pF 80
RL ≥ 1k
TA = 25°C 100
120
VS = ±5V
1.8
1.25
125
Gain/Phase vs Frequency
2.0
1.00
50
25
0
75 100
–25
AMBIENT TEMPERATURE, TA (°C)
1051/53 G03
Supply Current vs Temperature
Per Op Amp
Supply Current vs Supply Voltage
Per Op Amp
SHORT-CIRCUIT OUTPUT CURRENT, IOUT (mA)
3
1051/53 G02
1051/53 G01
– 30
4
1
–8
0
VS = ±5V
–220
10M
1051/53 G09
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LTC1051/LTC1053
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TYPICAL PERFOR A CE CHARACTERISTICS
Small Signal Transient Response
Overload Recovery
Large Signal Transient Response
400mV
INPUT
0
OUTPUT
50mV
/DIV
OUTPUT
2V/DIV
INPUT
100mV
INPUT
6V
0
OUTPUT
– 5V
2µs/DIV
AV = 1, RL = 10k, CL = 100pF
VS = ±5V, TA = 25°C
0.5ms
AV = –100
VS = ±5V
1051/53 G10
2µs/DIV
AV = 1, RL = 10k, CL = 100pF
VS = ±5V, TA = 25°C
1051/53 G11
1051/53 G12
LTC1051/LTC1053 DC to 10Hz Noise
VS = ±5V
TA = 25°C
1.4µVP-P
1µV
10 SEC
1 SEC
TEST CIRCUITS
Electrical Characteristics Test Circuit
DC 10Hz Noise Test Circuit
475k
100k
1M
0.01µF
V+
1k
2
3
–
1/2
LTC1051
+
10Ω
8
4
V–
6
2
OUTPUT
3
RL
–
1/2
LTC1051
+
6
158k
0.1µF
316k
475k
–
LT1012
0.01µF
TO X-Y
RECORDER
+
FOR 1Hz NOISE BW INCREASE ALL THE CAPACITORS BY A FACTOR OF 10.
1051/53 TC01
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LTC1051/LTC1053
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ACHIEVING PICOAMPERE/MICROVOLT PERFORMANCE
Picoamperes
In order to realize the picoampere level of accuracy of the
LTC1051/LTC1053, proper care must be exercised. Leakage currents in circuitry external to the amplifier can
significantly degrade performance. High quality insulation
should be used (e.g., Teflon, Kel-F); cleaning of all insulating surfaces to remove fluxes and other residues will
probably be necessary —particularly for high temperature
performance. Surface coating may be necessary to provide
a moisture barrier in high humidity environments.
Board leakage can be minimized by encircling the input
connections with a guard ring operated at a potential close
to that of the inputs: in inverting configurations, the guard
ring should be tied to ground; in noninverting connections,
to the inverting input. Guarding both sides of the printed
circuit board is required. Bulk leakage reduction depends
on the guard ring width.
Microvolts
Thermocouple effects must be considered if the LTC1051/
LTC1053’s ultra low drift op amps are to be fully utilized.
Any connection of dissimilar metals forms a thermoelectric junction producing an electric potential which varies
with temperature (Seebeck effect.) As temperature sensors, thermocouples exploit this phenomenon to produce
useful information. In low drift amplifier circuits, this effect
is a primary source of error.
Connectors, switches, relay contacts, sockets, resistors,
solder, and even copper wire are all candidates for thermal
EMF generation. Junctions of copper wire from different
manufacturers can generate thermal EMFs of 200nV/°C—
4 times the maximum drift specification of the LTC1051/
LTC1053. The copper/kovar junction, formed when wire or
printed circuit traces contact a package lead, has a thermal
EMF of approximately 35µV/°C—700 times the maximum
drift specification of the LTC1051/LTC1053.
Minimizing thermal EMF-induced errors is possible if
judicious attention is given to circuit board layout and
component selection. It is good practice to minimize the
number of junctions in the amplifier’s input signal path.
Avoid connectors, sockets, switches and relays where
possible. In instances where this is not possible, attempt
to balance the number and type of junctions so that
differential cancellation occurs. Doing this may involve
deliberately introducing junctions to offset unavoidable
junctions.
When connectors, switches, relays and/or sockets are
necessary, they should be selected for low thermal EMF
activity. The same techniques of thermally balancing and
coupling the matching junctions are effective in reducing
the thermal EMF errors of these components.
Resistors are another source of thermal EMF errors.
Table 1 shows the thermal EMF generated for different
resistors. The temperature gradient across the resistor is
important, not the ambient temperature. There are two
junctions formed at each end of the resistor and if these
junctions are at the same temperature, their thermal EMFs
will cancel each other. The thermal EMF numbers are
approximate and vary with resistor value. High values give
higher thermal EMF.
Table 1. Resistor Thermal EMF
RESISTOR TYPE
THERMAL EMF/°C GRADIENT
Tin Oxide
~mV/°C
Carbon Composition
~450µV/°C
Metal Film
~20µV/°C
Wire Wound
Evenohm
Manganin
~2µV/°C
~2µV/°C
Input Bias Current, Clock Feedthrough
At ambient temperatures below 60°C, the input bias current of the LTC1051/LTC1053 op amps’ is dominated by
the small amount of charge injection occurring during the
sampling and holding of the op amps’ input offset voltage.
The average value of the resulting current pulses is 10pA
to 15pA with sign convention shown in Figure 1.
IB+
+
IB–
TA < 60°C
1/2
LTC1051
–
IB+
+
TA > 85°C
1/2
LTC1051
IB–
–
(a)
(b)
1051/53 F01
Figure 1. LTC1051 Bias Current
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LTC1051/LTC1053
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RS = 0,
AV =11V/V
20mV/DIV
R2
100k
RS = 100k,
AV =11V/V
20mV/DIV
RS = 0,
AV =101V/V
20mV/DIV
R1
1k
–
1/2
LTC1051
RS
RS = 100k,
AV =101V/V
20mV/DIV
100µs/DIV
100µs/DIV
(a)
(b)
+
1051/53 F02
(c)
Figure 2. Clock Feedthrough
The charge injection at the op amp input pins will cause
small output spikes. This phenomenon is often referred to
as “clock feedthrough” and can be easily observed when
the closed-loop gain exceeds 10V/V (Figure 2). The magnitude of the clock feedthrough is temperature independent but it increases when the closed-loop gain goes up,
when the source resistance increases and when the gain
setting resistors increase (Figure 2a, 2b). It is important to
note that the output small spikes are centered at 0V level
and do not add to the output offset error budget. For
instance, with RS = 1MΩ, the typical output offset voltage
of Figure 2c is:
VOS(OUT) ≈ 108 • IB+ + 101VOS(IN)
A 10pA bias current will yield an output of 1mV ±100µV.
The output clock feedthrough can be attenuated by lowering the value of the gain setting resistors, i.e. R2 = 10k,
R1 = 100Ω, instead of 100k and 1k (Figure 2).
Clock feedthrough can also be attenuated by adding a
capacitor across the feedback resistor to limit the circuit
bandwidth below the internal sampling frequency
(Figure 3).
Input Capacitance
The input capacitance of the LTC1051/LTC1053 op amps
is approximately 12pF. When the LTC1051/LTC1053 op
amps are used with feedback factors approaching unity,
the feedback resistor value should not exceed 7k for
industrial temperature range and 5k for military temperature range. If a higher feedback resistor value is required,
a feedback capacitor of 20pF should be placed across the
feedback resistor. Note that the most common circuits
with feedback factors approaching unity are unity gain
followers and instrumentation amplifier front ends.
(See Figure 4.)
RS = 100k
AV =101V/V
20mV/DIV
As the ambient temperature rises, the leakage current of
the input protection devices increases, while the charge
injection component of the bias current, for all practical
purposes, stays constant. At elevated temperatures (above
85°C) the leakage current dominates and the bias current
of both inputs assumes the same sign.
RS = 1MΩ
AV =101V/V
100µs/DIV
C
1000pF
R1
1k
2
RS
3
–
R2
100k
1/2
LTC1051
1
+
1051/53 F03
Figure 3. Adding a Feedback Capacitor to
Eliminate Clock Feedthrough
R2 < 7k, IF R1 > >R2
R1
2
3
–
1/2
LTC1051
1
+
1051/53 F04
Figure 4. Operating the LTC1051
with Feedback Factors Approaching Unity
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LTC1051/LTC1053
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LTC1051/LTC1053 as AC Amplifiers
Aliasing
Although initially chopper stabilized op amps were designed to minimize DC offsets and offset drifts, the
LTC1051/LTC1053 family, on top of its outstanding DC
characteristics, presents efficient AC performance. For
instance, at single 5V supply, each op amp typically
consumes 0.5mA and still provides 1.8MHz gain bandwidth product and 3V/µs slew rate. This, combined with
almost distortionless swing to the supply rails (Figure 8),
makes the LTC1051/LTC1053 op amps nearly general
purpose. To further expand this idea (the “aliasing” phenomenon) which can occur under AC conditions, should
be described and properly evaluated.
The LTC1051/LTC1053 are equipped with internal circuitry to minimize aliasing. Aliasing, no matter how small,
occurs when the input signal approaches and exceeds the
internal sampling rate. Aliasing is caused by the sampled
data nature of the chopper op amps. A generalized study
of this phenomenon is beyond the scope of a data sheet;
however, a set of rules of thumb can answer many
questions:
B: MAG
RANGE: 9dBV
1. Alias signals can be generally defined as output AC
signals at a frequency of nfCLK ± mfIN. The nfCLK term is the
internal sampling frequency of the chopper stabilized op
amps and its harmonics; mfIN is the frequency of the input
signal and its harmonics, if any.
STATUS: PAUSED
RMS: 25
20dBV
R2
10k
5V
80dB
15dB
/DIV
R1
1k
fIN
0.8VP-P
–100
START: 100Hz
X: 1825Hz
BW: 47.742Hz
Y: – 70.72dBV
0.1µF
2
3
–
1/2
LTC1051
fCLK – fIN
50pF
STOP: 5 100Hz
2fIN
VOUT
+
0.1µF
– 5V
fIN = 750Hz
1
1051/53 F05a
2fCLK – fIN
Figure 5a. Output Voltage Spectrum of 1/2 LTC1051 Operating as an Inverting Amplifier with Gain of 10,
and Amplifying a 750Hz/800mV, Input AC Signal
A: MAG
RANGE: 11dBV
STATUS: PAUSED
RMS: 25
20dBV
74dB
15dB
/DIV
–100
CENTER: 10 000Hz
X: 5550Hz
6fCLK – fIN
BW: 95.485Hz
Y: – 63.91dBV
SPAN: 10 000Hz
fIN = 10kHz
Figure 5b. Same as Figure 5a, but the AC Input Signal is 900mV, 10kHz
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LTC1051/LTC1053
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2. If we arbitrarily accept that “aliasing” occurs when
output alias signals reach an amplitude of 0.01% or more
of the output signal, then: the approximate minimum
frequency of an AC input signal which will cause aliasing
is equal to the internal clock frequency multiplied by the
square root of the op amp feedback factor. For instance,
with closed-loop gain of –10, the feedback factor is 1/11
and if fCLK = 2.6kHz, alias signals can be detected when
the frequency of the input signal exceeds 750Hz to 800Hz
(Figure 5a).
3. The number of alias signals increases when the input
signal frequency increases (Figure 5b).
13dBV
B: MAG
RANGE: 9dBV
4. When the frequency, fIN, of the input signal is less than
fCLOCK, the alias signal(s) amplitude(s) directly scale with
the amplitude of the incoming signal. The output “signal to
alias ratio” cannot be increased by just boosting the input
signal amplitude. However, when the input AC signal
frequency well exceeds the clock frequency, the amplitude
of the alias signals does not directly scale with the input
amplitude. The “signal to alias ratio” increases when the
output swings closely to the rails. (See Figure 5b and
Figure 7.) It is important to note that the LTC1051/
LTC1053 op amps, under light loads (RL ≥ 10k), swing
closely to the supply rails without generating harmonic
distortion (Figure 8).
STATUS: PAUSED
RMS: 25
10k
5V
83.5dB
15dB
/DIV
0.1µF
10k
–
1/2
LTC1051
+
–107
CENTER: 2 625Hz
X: 2535Hz
BW: 19.097Hz
Y: – 74.16dBV
NOTE: THE fCLK – fIN = 85Hz
ALIAS FREQUENCY IS 95dB
2fCLK – fIN
DOWN FROM THE OUTPUT LEVEL
fCLK
SPAN: 2 000Hz
50pF
0.1µF
VIN = 10kHz
8VP-P
– 5V
1051/53 F05a
fIN = 2.685kHz
Figure 6a. Output Voltage Spectrum of 1/2 LTC1051 Operating as a Unity-Gain Inverting Amplifier.
VS = ±5V, RL = 10k, CL = 50pF, VIN = 8VP-P, 2.685kHz
B: MAG
RANGE: 9dBV
STATUS: PAUSED
RMS: 50
13dBV
15dB
80dB
15dB
/DIV
–107
CENTER: 10 000Hz
X: 10000Hz
5fCLK – fIN
fIN – 2fCLK
BW: 95.485Hz
Y: 7.98dBV
SPAN: 10 000Hz
1kHz
2 • fCLK
fIN – fCLK
fIN = 10kHz
6fCLK – fIN
NOTE: ALL ALIAS FREQUENCY
80dB TO 84dB DOWN FROM OUTPUT
Figure 6b. Output Voltage Spectrum of 1/2 LTC1051 Operating as a Unity-Gain Inverting Amplifier.
VS = ±5V, RL = 10k, CL = 50pF, VIN = 8VP-P, 10kHz
10513fa
9
LTC1051/LTC1053
U
W
U U
APPLICATIO S I FOR ATIO
5. For unity-gain inverting configuration, all the alias
frequencies are 80dB to 84dB down from the output signal
(Figures 6a, 6b). Combined with excellent THD under wide
swing, the LTC1051/LTC1053 op amps make efficient
unity gain inverters.
For gain higher than –1, the “signal to alias” ratio decreases at an approximate rate of –6dB per decade of
closed-loop gain (Figure 9).
6. For closed-loop gains of –10 or higher, the “signal to
alias” ratio degrades when the value of the feedback gain
setting resistor increases beyond 50k. For instance, the
SYSTEM BUSY, ONLY ABORT COMMANDS ALLOWED
RANGE: 11dBV
68dB value of Figure 7 decreases to 56dB if a (1k, 100k)
resistor set is used to set the gain of –100.
7. When the LTC1051/LTC1053 are used as noninverting
amplifiers, all the previous approximate rules of thumb
apply with the following exceptions: when the closed-loop
gain is 10(V/V) and below, the “signal to alias” ratio is 1dB
to 3dB less than the inverting case; when the closed-loop
gain is 100(V/V), the degradation can be up to 9dB,
especially when the input signal is much higher than the
clock frequency (i.e. fIN = 10kHz).
8. The signal/alias ratio performance improves when the
op amp has bandlimited loop gain.
STATUS: PAUSED
20dBV
R2
10k
5V
68dB
15dB
/DIV
R1
100Ω
0.1µF
–
1/2
LTC1051
90mVP-P
10kHz
–100
CENTER: 10 000Hz
X: 5475Hz
6fCLK – fIN
BW: 95.485Hz
Y: –58.05dBV
VOUT
+
50pF
0.1µF
SPAN: 10 000Hz
– 5V
1051/53 F07
fIN =10kHz
10
9
VS = ±8V, TA ≤85°C
VOUT ± SWING (±V)
8
7
6
VS = ±5V, TA ≤85°C
5
4
VS = ±2.5V, TA ≤85°C
3
2
NEGATIVE SWING
POSITIVE SWING
1
0
0
1k 2k 3k 4k 5k 6k 7k 8k 9k 10k
RL (LOAD RESISTANCE,Ω)
1051/53 G08
Figure 8. Output Voltage Swing vs Load
OUTPUT SIGNAL TO ALIAS SIGNAL(S) RATIO (dB)
Figure 7. Output Voltage Spectrum of 1/2 LTC1051 Operating as an Inverting Amplifier with a Gain of –100 and
Amplifiying a 90mVP-P, 10kHz Input Signal. With a 9VP-P Output Swing the Measured 2nd Harmonic (20kHz)
was 75 Down from the 10kHz Input Signal
90
VS = ±5V
fIN ≤10kHz
80
70
60
50
40
30
20
10
1
10
INVERTING CLOSED-LOOP GAIN
100
1051/53 G09
Figure 9. Signal to Alias Ratio vs
Closed-Loop Gain
10513fa
10
LTC1051/LTC1053
U
TYPICAL APPLICATIO S
Obtaining Ultralow VOS Drift and Low Noise
The dual chopper op amp buffers the inputs of A1 and
corrects its offset voltage and offset voltage drift. With the
R, C values shown, the power-up warm up time is typically
20 seconds. The step response of the composite amplifier
does not present settling tails. The LT1007 should be used
when extremely low noise; VOS and VOS drift are sought
when the input source resistance is low—for instance a
350Ω strain gauge bridge. The LT1012 or equivalent
should be used when low bias current (100pA) is also
required in conjunction with DC to 10Hz low noise and low
VOS and VOS drift. The measured typical input offset
voltages were less than 2µV.
B
+
5
2
3
–
1/2
LTC1051
+
R4
1
6
+
1/2
LTC1051
7
–
5V
C1
R5
OUT
C2
3
2
–
R1
1
+
R2
R3
8
A1
6
OUT
–
A
1051/53 AC01a
A1
R1
R2
R3
R4
R5
C1
C2
eOUT(DC – 1Hz)**
eOUT(DC – 10Hz)**
LT1007
3k
2k
340k
10k
100k
0.01µF
0.001µF
0.1µVP-P
0.15µVP-P
LT1012*
750Ω
57Ω
250k
10k
100k
0.01µF
0.001µF
0.3µVP-P
0.4µVP-P
* Interchange connections A and B .
** Noise measured in a 10 sec window. Peak-to-peak noise was also measured for 10 continuous minutes: With the LT1007 op amp the recorded noise was less than 0.2µVP-P for both DC-1Hz
and DC-10Hz.
LTC1051/LT1007 Peak-to-Peak Noise
VS = ±5V
0.2µV/DIV
DC TO 1Hz
NOISE
DC TO 10Hz
NOISE
1 SEC/DIV
1051/53 AC01b
10513fa
11
LTC1051/LTC1053
U
TYPICAL APPLICATIO S
Paralleling Choppers to Improve Noise
NOTE: THIS CIRCUIT CAN ALSO BE USED AS A
DIFFERENCE AMPLIFIER FOR STRAIN GAUGES.
CONNECT R2/3 AND R1/3 FROM NONINVERTING
INPUTS, SHORTED TOGETHER, TO GROUND AND
TO SOURCE RESPECTIVELY.
R2
R1
VIN
2
3
Differential Voltage to Current Converter
–
1/4
LTC1053
R
1
0.1µF
3
V1
R
+
2
+
1
1/4
LTC1053
20k
–
5V
5V
10k
10k
10k
R2
0.1µF
RG
R1
6
5
13
–
1/4
LTC1053
R
7
12
+
5
4
–
+
13
14
1/4
LTC1053
VOUT
11
V2
12
R2
9
10
–
1/4
LTC1053
–
1/4
LTC1053
10k
14
6
–
1/4
LTC1053
+
7
10
4
–
1/4
LTC1053
+
+
10k
0.1µF
VOUT/ VIN = 3(R2/R1); INPUT DC – 10Hz NOISE
≅ 0.8µVP-P = NOISE OF EACH PARALLELED OP AMP/√3
IOUT
8
11
–5V
10k
R
8
20k
9
+
• IOUT = 2(V2 – V1)/RG
• BW = 100Hz
• IOUTMAX = 1mA
0.1µF
–5V
R1
20k
10k
0.1µF
0.1µF
10k
RLOAD
1051/53 AC03
1051/53 AC02
Multiplexed Differential Thermometer
100Ω
255k
1k
0.068µF
2
TYPE K
–
3
+
–
1/4
LTC1053
1
T2
ABSOLUTE
TEMPERATURE
+
ABSOLUTE
TEMPERATURE
0.1µF
10k
255k
100Ω
1k
5V
2
5V
0.068µF
6
K
7
TYPE K
–
LT1025A
–
5
+
10k
1/4
LTC1053
7
T1
S1
10k
+
13
–
4
1/4
LTC1053
12
0.1µF
+
11
14
OUTPUT
(DIFFERENTIAL
TEMPERATURE)
10k
GND
4
R–
100Ω
255k
5
1k
0.068µF
9
TYPE K
–
10
+
0.1µF
–
1/4
LTC1053
+
8
TREF
ALL FIXED RESISTORS ARE 1% METAL FILM
OUTPUT = TREF – T1 OR TREF – T2(10mV PER °C)
ACCURACY = (±0.1% FROM 25°C TO 150°C)
1051/53 AC04
10513fa
12
LTC1051/LTC1053
U
TYPICAL APPLICATIO S
Dual Instrumentation Amplifier
+
Six Decade Log Amplifier
5V
LTC1043
3
8
7
1µF
2
11
5V
Q1
Q1
0.1µF
3k
0.1%
2
1nA < IIN 100dB
VOS ≅ 3µV
INPUT REFERRED NOISE ≅ 2µVP-P
1051/53 AC06
Linearized Platinum Signal Conditioner
250k*
5V
3
2
+
10k*
8
1/2
LTC1051
–
(LINEARITY CORRECTION LOOP)
5V
1
2.4k
274k*
4
50k
ZERO
ADJUST
0.1µF
LT1009
2.5V
8.25k*
2k
4
8
7
11
1µF
6
5
1µF
6
2
887Ω
1µF
1µF
12
5
0V TO 4V =
0°C TO 400°C
±0.05°C
+
1/2
LTC1051
–
7
1k
GAIN
ADJUST
5k
3
8.06k*
13
14
1/2 LTC1043
15
IK
RP
100Ω
AT 0°C
18
1/2 LTC1043
16
0.01µF
RP = ROSEMOUNT 118MFRTD
*1% FILM RESISTOR
TRIM SEQUENCE:
SET SENSOR TO 0°C VALUE. ADJUST ZERO FOR 0V OUT
SET SENSOR TO 100°C VALUE. ADJUST GAIN FOR 1.000V OUT
SET SENSOR TO 400°C VALUE. ADJUST LINEARITY FOR 4.000V OUT
REPEAT AS REQUIRED. FOR MORE INFORMATION REFER TO AN3
1k
17
1051/53 AC07
10513fa
13
LTC1051/LTC1053
U
PACKAGE DESCRIPTIO
J Package
8-Lead CERDIP (Narrow 0.300, Hermetic)
(LTC DWG # 05-08-1110)
.300 BSC
(7.62 BSC)
CORNER LEADS OPTION
(4 PLCS)
.008 – .018
(0.203 – 0.457)
0° – 15°
.015 – .060
(0.381 – 1.524)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.405
(10.287)
MAX
.005
(0.127)
MIN
.200
(5.080)
MAX
8
NOTE: LEAD DIMENSIONS APPLY TO SOLDER
DIP/PLATE OR TIN PLATE LEADS
.014 – .026
(0.360 – 0.660)
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
.045 – .065
(1.143 – 1.651)
6
7
2
3
4
.125
3.175
MIN
.100
(2.54)
BSC
J8 0801
OBSOLETE PACKAGE
N Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
.300 – .325
(7.620 – 8.255)
(
.400*
(10.160)
MAX
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
+.035
.325 –.015
+0.889
8.255
–0.381
.130 ± .005
(3.302 ± 0.127)
.045 – .065
(1.143 – 1.651)
.120
(3.048) .020
MIN (0.508)
MIN
.018 ± .003
.100
(2.54)
BSC
)
(0.457 ± 0.076)
8
7
6
5
1
2
3
4
.255 ± .015*
(6.477 ± 0.381)
N8 1002
NOTE:
1. DIMENSIONS ARE
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
N Package
14-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
.300 – .325
(7.620 – 8.255)
.770*
(19.558)
MAX
14
13
12
11
10
9
8
.008 – .015
(0.203 – 0.381)
.255 ± .015*
(6.477 ± 0.381)
+.035
.325 –.015
1
2
3
4
5
6
7
(
8.255
+0.889
–0.381
NOTE:
1. DIMENSIONS ARE
)
.045 – .065
(1.143 – 1.651)
.130 ± .005
(3.302 ± 0.127)
.020
(0.508)
MIN
.065
(1.651)
TYP
.120
(3.048)
MIN
.005
(0.125) .100
MIN (2.54)
BSC
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
.018 ± .003
(0.457 ± 0.076)
N14 1002
10513fa
14
LTC1051/LTC1053
U
PACKAGE DESCRIPTIO
SW Package
16-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
.050 BSC .045 ±.005
.030 ±.005
TYP
.398 – .413
(10.109 – 10.490)
NOTE 4
15
16
N
14
12
13
10
11
9
N
.325 ±.005
.420
MIN
.394 – .419
(10.007 – 10.643)
NOTE 3
1
2
3
NOTE:
1. DIMENSIONS IN
N/2
N/2
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES
ON THE BOTTOM OF PACKAGES ARE THE
MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR
WITHOUT ANY OF THE OPTIONS
4. THESE DIMENSIONS DO NOT INCLUDE
MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT
EXCEED .006" (0.15mm)
RECOMMENDED SOLDER PAD LAYOUT
.005
(0.127)
RAD MIN
2
1
.291 – .299
(7.391 – 7.595)
NOTE 4
.010 – .029 × 45°
(0.254 – 0.737)
3
5
4
7
6
8
.037 – .045
(0.940 – 1.143)
.093 – .104
(2.362 – 2.642)
0° – 8° TYP
.009 – .013
(0.229 – 0.330)
.050
(1.270)
BSC
NOTE 3
.004 – .012
(0.102 – 0.305)
.014 – .019
(0.356 – 0.482)
TYP
.016 – .050
(0.406 – 1.270)
S16 (WIDE) 0502
SW Package
18-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
.050 BSC .045 ±.005
.030 ±.005
TYP
.447 – .463
(11.354 – 11.760)
NOTE 4
N
18
17
16
15
14
13
12
11
10
N
.325 ±.005
.420
MIN
.394 – .419
(10.007 – 10.643)
NOTE 3
1
2
3
N/2
NOTE:
1. DIMENSIONS IN
N/2
RECOMMENDED SOLDER PAD LAYOUT
.005
(0.127)
RAD MIN
.009 – .013
(0.229 – 0.330)
.291 – .299
(7.391 – 7.595)
NOTE 4
.010 – .029 × 45°
(0.254 – 0.737)
1
2
3
.093 – .104
(2.362 – 2.642)
4
5
6
7
8
9
.037 – .045
(0.940 – 1.143)
0° – 8° TYP
NOTE 3
.016 – .050
(0.406 – 1.270)
.050
(1.270)
BSC
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES
ON THE BOTTOM OF PACKAGES ARE THE
MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR
WITHOUT ANY OF THE OPTIONS
4. THESE DIMENSIONS DO NOT INCLUDE
MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT
EXCEED .006" (0.15mm)
.004 – .012
(0.102 – 0.305)
.014 – .019
(0.356 – 0.482)
TYP
S18 (WIDE) 0502
10513fa
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.
15
LTC1051/LTC1053
U
TYPICAL APPLICATIO S
DC Accurate, 3rd Order, 100Hz, Butterworth Antialiasing Filter
Dynamic Range
8V
R1
16.5k
R2
118k
R3
21k
C
0.1µF
C2
0.1µF
2
3
THD + NOISE (%)
C1
0.1µF
VIN
0.1µF
+
1/2
LTC1051
–
1
VOUT
0.01
R2A
10k
0.0001
0.1
1051/53 AC09
–
1/2
LTC1051
CA
0.22µF
Dynamic Range
+
60dB
0.1
C1B
0.0022µF
R1B
50k
THD + NOISE (%)
C1A
0.022µF
R3B
412k
–
1/2
LTC1051
CB
0.022µF
120dB
5.0
1.0
VIN (VRMS), fIN = 30Hz
1051/53 AC08
R2B
50k
R3A
26.7k
VS = ±8V 100dB
0.001
DC Accurate, 18-Bit, 4th Order Antialiasing Bessel (Linear Phase),
100Hz, Lowpass Filter
VIN
80dB
VS = ±5V
0.1µF
–8V
WIDEBAND NOISE 9µVRMS
THD + NOISE ≅ 0.0012%, 1VRMS < VIN < 2VRMS, VS = ±8V
VOS(OUT) < 5µV
R1A
10k
60dB
0.1
VS = ±5V
0.01
0.001
80dB
VS = ±8V
100dB
VOUT
+
WIDEBAND RMS NOISE 4.5µVRMS
THD + NOISE ≅ 0.0005% (= 106dB DYNAMIC RANGE), 2VRMS ≤ VIN ≤ 3VRMS
VOS OUT < 10µV
0.0001
0.1
1.0
VIN (VRMS), fIN = 30Hz
120dB
5.0
1051/53 AC10
1051/53 AC11
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1047
Dual µPower Zero-Drift 0p Amp
IS = 80µA/0p Amp, 16-Lead SW Package
LTC1049
Low Power Zero-Drift 0p Amp
IS = 200µA, SO-8 Package
LTC1050
Precision Zero-Drift Op Amp with Internal
Capacitors
VOS (Max) = 5µV, VSUPPLY (Max) = 16.5V
LTC2050/LTC2051/LTC2052
Single/Dual/Quad Zero-Drift 0p Amps
SOT-23/MS8/GN16 Packages
LTC2053
Zero-Drift Instrumentation Amp
Resistor Programmable Gain, R-R
10513fa
16
Linear Technology Corporation
LW/TP 1202 1K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 1990
工商网监
湘ICP备2023018690号
