LTC2053/LTC2053-SYNC
Precision, Rail-to-Rail,
Zero-Drift, Resistor-Programmable
Instrumentation Amplifier
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FEATURES
DESCRIPTIO
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The LTC®2053 is a high precision instrumentation amplifier. The CMRR is typically 116dB with a single or dual 5V
supply and is independent of gain. The input offset voltage
is guaranteed below 10µV with a temperature drift of less
than 50nV/°C. The LTC2053 is easy to use; the gain is
adjustable with two external resistors, like a traditional
op amp.
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■
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116dB CMRR Independent of Gain
Maximum Offset Voltage: 10µV
Maximum Offset Voltage Drift: 50nV/°C
Rail-to-Rail Input
Rail-to-Rail Output
2-Resistor Programmable Gain
Supply Operation: 2.7V to ±5.5V
Typical Noise: 2.5µVP-P (0.01Hz to 10Hz)
Typical Supply Current: 750µA
LTC2053-SYNC Allows Synchronization to
External Clock
Available in MS8 and 3mm × 3mm × 0.8mm
DFN Packages
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APPLICATIO S
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Thermocouple Amplifiers
Electronic Scales
Medical Instrumentation
Strain Gauge Amplifiers
High Resolution Data Acquisition
The LTC2053 uses charge balanced sampled data techniques to convert a differential input voltage into a single
ended signal that is in turn amplified by a zero-drift
operational amplifier.
The differential inputs operate from rail-to-rail and the
single ended output swings from rail-to-rail. The LTC2053
can be used in single supply applications, as low as 2.7V.
It can also be used with dual ±5.5V supplies. The LTC2053
requires no external clock, while the LTC2053-SYNC has
a CLK pin to synchronize to an external clock.
The LTC2053 is available in an MS8 surface mount package. For space limited applications, the LTC2053 is available in a 3mm × 3mm × 0.8mm dual fine pitch leadless
package (DFN).
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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TYPICAL APPLICATIO
Typical Input Referred Offset vs Input
Common Mode Voltage (VS = 3V)
Differential Bridge Amplifier
3V
15
VS = 3V
VREF = 0V
TA = 25°C
R < 10k
8
2
–
7
LTC2053
3
OUT
6
+
5
R2 10k
1, 4
GAIN = 1+
R2
R1
0.1µF
R1
10Ω
INPUT OFFSET VOLTAGE (µV)
0.1µF
10
5
0
G = 1000
G = 100
–5
G = 10
–10
G=1
–15
2053 TA01
0
2.5
1.0
1.5
2.0
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
2053 TA01b
2053syncfb
1
LTC2053/LTC2053-SYNC
W W
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W
ABSOLUTE
AXI U RATI GS
(Note 1)
Total Supply Voltage (V + to V –) ............................... 11V
Input Current ...................................................... ±10mA
⏐VIN+ – VREF⏐ ........................................................ 5.5V
⏐VIN– – VREF⏐ ........................................................ 5.5V
Output Short Circuit Duration .......................... Indefinite
Operating Temperature Range
LTC2053C, LTC2053C-SYNC ................... 0°C to 70°C
LTC2053I, LTC2053I-SYNC ................ – 40°C to 85°C
LTC2053H ........................................ – 40°C to 125°C
Storage Temperature Range
MS8 Package ................................... – 65°C to 150°C
DD Package ...................................... – 65°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
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W
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PACKAGE/ORDER I FOR ATIO
ORDER PART NUMBER
TOP VIEW
EN/CLK†
–IN
+IN
V–
1
2
3
4
8
7
6
5
V+
OUT
RG
REF
MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 200°C/W
†
LTC2053CMS8
LTC2053IMS8
LTC2053HMS8
LTC2053CMS8-SYNC
LTC2053IMS8-SYNC
MS8 PART MARKING
PIN 1 IS EN ON LTC2053,
CLK ON LTC2053-SYNC
LTVT
LTJY
LTAFB
ORDER PART NUMBER
TOP VIEW
EN
1
8 V+
–IN
2
7 OUT
+IN
3
6 RG
V–
4
5 REF
LTC2053CDD
LTC2053IDD
LTC2053HDD
DD PART MARKING
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
*LAEQ
TJMAX = 125°C, θJA = 160°C/W
UNDERSIDE METAL INTERNALLY
CONNECTED TO V–
(PCB CONNECTION OPTIONAL)
*LTBNP
*The temperature grade (C, I, or H) is indicated on the shipping container. 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. V + = 3V, V – = 0V, REF = 200mV. Output voltage swing is referenced
to V –. All other specifications reference the OUT pin to the REF pin.
PARAMETER
CONDITIONS
TYP
MAX
UNITS
Gain Error
AV = 1
●
MIN
0.001
0.01
%
Gain Nonlinearity
AV = 1, LTC2053
AV = 1, LTC2053-SYNC
●
●
3
3
12
15
ppm
ppm
Input Offset Voltage (Note 2)
VCM = 200mV
–5
±10
µV
Average Input Offset Drift (Note 2)
TA = – 40°C to 85°C
TA = 85°C to 125°C
●
●
–1
±50
–2.5
nV/°C
µV/°C
Average Input Bias Current (Note 3)
VCM = 1.2V
●
4
10
nA
Average Input Offset Current (Note 3)
VCM = 1.2V
●
1
3
nA
Input Noise Voltage
DC to 10Hz
Common Mode Rejection Ratio
(Notes 4, 5)
AV = 1, VCM = 0V to 3V, LTC2053C, LTC2053C-SYNC
AV = 1, VCM = 0.1V to 2.9V, LTC2053I, LTC2053I-SYNC
AV = 1, VCM = 0V to 3V, LTC2053I, LTC2053I-SYNC
AV = 1, VCM = 0.1V to 2.9V, LTC2053H
AV = 1, VCM = 0V to 3V, LTC2053H
●
●
●
●
●
100
100
95
100
85
2.5
µVP-P
113
113
113
dB
dB
dB
dB
dB
2053syncfb
2
LTC2053/LTC2053-SYNC
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V + = 3V, V – = 0V, REF = 200mV. Output voltage swing is referenced
to V –. All other specifications reference the OUT pin to the REF pin.
PARAMETER
CONDITIONS
MIN
TYP
Power Supply Rejection Ratio (Note 6)
VS = 2.7V to 6V
●
110
116
dB
= 2k to V –
●
●
2.85
2.95
2.94
2.98
V
V
Output Voltage Swing High
RL
RL = 10k to V –
●
Output Voltage Swing Low
Supply Current
No Load
Supply Current, Shutdown
VEN ≥ 2.5V, LTC2053 Only
●
0.75
EN/CLK Pin Input Low Voltage, VIL
EN/CLK Pin Input High Voltage, VIH
EN/CLK Pin Input Current
MAX
UNITS
20
mV
1
mA
10
µA
0.5
V
2.5
VEN/CLK
= V–
V
– 0.5
–10
µA
Internal Op Amp Gain Bandwidth
200
kHz
Slew Rate
0.2
V/µs
3
kHz
Internal Sampling Frequency
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V+ = 5V,
V– = 0V, REF = 200mV. Output voltage swing is referenced to V–. All other specifications reference the OUT pin to the REF pin.
PARAMETER
CONDITIONS
Gain Error
AV = 1
●
Gain Nonlinearity
AV = 1
●
Input Offset Voltage (Note 2)
VCM = 200mV
Average Input Offset Drift (Note 2)
TA = – 40°C to 85°C
TA = 85°C to 125°C
Average Input Bias Current (Note 3)
Average Input Offset Current (Note 3)
Common Mode Rejection Ratio
(Notes 4, 5)
AV = 1, VCM = 0V to 5V, LTC2053C
AV = 1, VCM = 0V to 5V, LTC2053C-SYNC
AV = 1, VCM = 0.1V to 4.9V, LTC2053I
AV = 1, VCM = 0.1V to 4.9V, LTC2053I-SYNC
AV = 1, VCM = 0V to 5V, LTC2053I, LTC2053I-SYNC
AV = 1, VCM = 0.1V to 4.9V, LTC2053H
AV = 1, VCM = 0V to 5V, LTC2053H
●
●
●
●
●
●
●
105
100
105
100
95
100
85
116
116
116
116
116
dB
dB
dB
dB
dB
dB
dB
Power Supply Rejection Ratio (Note 6)
VS = 2.7V to 6V
●
110
116
dB
= 2k to V –
●
●
4.85
4.95
4.94
4.98
V
V
Output Voltage Swing High
MIN
TYP
MAX
UNITS
0.001
0.01
%
3
10
ppm
–5
±10
µV
●
●
–1
±50
–2.5
nV/°C
µV/°C
VCM = 1.2V
●
4
10
nA
VCM = 1.2V
●
1
3
nA
RL
RL = 10k to V –
●
Output Voltage Swing Low
Supply Current
No Load
Supply Current, Shutdown
VEN ≥ 4.5V, LTC2053 Only
●
0.85
EN/CLK Pin Input Low Voltage, VIL
EN/CLK Pin Input High Voltage, VIH
EN/CLK Pin Input Current
20
mV
1.1
mA
10
µA
0.5
V
–10
µA
4.5
VEN/CLK = V –
V
–1
Internal Op Amp Gain Bandwidth
200
kHz
Slew Rate
0.2
V/µs
3
kHz
Internal Sampling Frequency
2053syncfb
3
LTC2053/LTC2053-SYNC
Gain Error
AV = 1
●
0.001
0.01
Gain Nonlinearity
AV = 1
●
3
10
Input Offset Voltage (Note 2)
VCM = 0V
10
±20
µV
Average Input Offset Drift (Note 2)
TA = – 40°C to 85°C
TA = 85°C to 125°C
●
●
–1
±50
–2.5
nV/°C
µV/°C
VCM = 1V
●
4
10
nA
Average Input Offset Current (Note 3)
VCM = 1V
●
1
3
nA
Common Mode Rejection Ratio
(Notes 4, 5)
(Notes 4, 5)
AV = 1, VCM = – 5V to 5V, LTC2053C
AV = 1, VCM = – 5V to 5V, LTC2053C-SYNC
AV = 1, VCM = – 4.9V to 4.9V, LTC2053I
AV = 1, VCM = – 4.9V to 4.9V, LTC2053I-SYNC
AV = 1, VCM = – 5V to 5V, LTC2053I, LTC2053I-SYNC
AV = 1, VCM = –4.9V to 4.9V, LTC2053H
AV = 1, VCM = –5V to 5V, LTC2053H
●
●
●
●
●
●
●
Power Supply Rejection Ratio (Note 6)
VS = 2.7V to 11V
●
Maximum Output Voltage Swing
RL = 2k to GND, C and I Grades
RL = 10k to GND, All Grades
RL = 2k to GND, LTC2053H Only
●
●
●
Supply Current
No Load
●
Supply Current, Shutdown
VEN ≥ 4.5V, LTC2053 Only
Average Input Bias Current (Note 3)
105
100
105
100
95
100
90
%
ppm
118
118
118
118
118
dB
dB
dB
dB
dB
dB
dB
110
116
dB
±4.5
±4.6
±4.4
±4.8
±4.9
±4.8
V
V
V
0.95
1.3
mA
20
µA
EN Pin Input Low Voltage, VIL
– 4.5
V
CLK Pin Input Low Voltage, VIL
0.5
V
EN/CLK Pin Input High Voltage, VIH
2053syncfb
4
LTC2053/LTC2053-SYNC
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TYPICAL PERFOR A CE CHARACTERISTICS
Input Offset Voltage vs Input
Common Mode Voltage
15
5
0
G = 1000
G = 100
–5
G = 10
–10
G = 1000
5
0
G = 100
–5
G=1
–10
–15
0
2.5
1.0
1.5
2.0
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
Input Offset Voltage vs Input
Common Mode Voltage
5
0
TA = 85°C
TA = 25°C
–10
TA = 70°C
TA = –55°C
–15
–20
0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
TA = 85°C
5
TA = 70°C
0
–5
TA = 25°C
–10
–15
–20
3.0
–20
–40
–60
TA = 125°C
0
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
2053 G07
TA = 25°C
5
TA = 85°C
0
TA = 70°C
–5
–10
–20
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
5
TA = –55°C
–5
–1
1
3
–3
INPUT COMMON MODE VOLTAGE (V)
Input Offset Voltage vs Input
Common Mode Voltage
100
20
0
TA = 85°C
TA = 25°C
–20
–40
–60
5
2053 G06
H-GRADE PARTS
VS = 5V
VREF = 0V
G = 10
40
5
10
2053 G05
INPUT OFFSET VOLTAGE (µV)
INPUT OFFSET VOLTAGE (µV)
TA = 25°C
TA = 85°C
–1
1
3
–3
INPUT COMMON MODE VOLTAGE (V)
–15
TA = –55°C
60
20
–5
VS = ±5V
15 VREF = 0V
G = 10
Input Offset Voltage vs Input
Common Mode Voltage
H-GRADE PARTS
VS = 3V
VREF = 0V
G = 10
0
–10
20
10
Input Offset Voltage vs Input
Common Mode Voltage
40
G=100
–5
Input Offset Voltage vs Input
Common Mode Voltage
VS = 5V
15 VREF = 0V
G = 10
2053 G04
60
G=1
0
2053 G03
20
INPUT OFFSET VOLTAGE (µV)
INPUT OFFSET VOLTAGE (µV)
20
10
G=1000
5
Input Offset Voltage vs Input
Common Mode Voltage
VS = 3V
15 VREF = 0V
G = 10
G=10
2053 G02
2053 G01
–5
10
–20
5
INPUT OFFSET VOLTAGE (µV)
–15
VS = ±5V
15 VREF = 0V
TA = 25°C
–15
G = 10
G=1
INPUT OFFSET VOLTAGE (µV)
10
20
VS = 5V
VREF = 0V
10 TA = 25°C
INPUT OFFSET VOLTAGE (µV)
VS = 3V
VREF = 0V
TA = 25°C
INPUT OFFSET VOLTAGE (µV)
INPUT OFFSET VOLTAGE (µV)
15
Input Offset Voltage vs Input
Common Mode Voltage
Input Offset Voltage vs Input
Common Mode Voltage
TA = 125°C
H-GRADE PARTS
80 VS = ±5V
60 VREF = 0V
G = 10
40
20
TA = 85°C
0
TA = 25°C
–20
–40
–60
TA = 125°C
–80
–100
0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
5
2053 G08
–5
–1
1
3
–3
INPUT COMMON MODE VOLTAGE (V)
5
2053 G09
2053syncfb
5
LTC2053/LTC2053-SYNC
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Error Due to Input RS vs Input
Common Mode (CIN < 100pF)
Error Due to Input RS vs Input
Common Mode (CIN < 100pF)
Error Due to Input RS vs Input
Common Mode (CIN < 100pF)
Error Due to Input RS Mismatch
vs Input Common Mode
(CIN < 100pF)
Error Due to Input RS Mismatch
vs Input Common Mode
(CIN < 100pF)
Error Due to Input RS Mismatch
vs Input Common Mode
(CIN < 100pF)
Error Due to Input RS vs Input
Common Mode (CIN > 1µF)
Error Due to Input RS vs Input
Common Mode (CIN > 1µF)
Error Due to Input RS vs Input
Common Mode (CIN > 1µF)
ADDITIONAL OFFSET ERROR (µV)
60
V
40
20
0
–20
–40
–60
0
2.5
1.0
1.5
2.0
0.5
INPUT COMMON MODE VOLTAGE (V)
3.0
2053 G10
2053syncfb
6
LTC2053/LTC2053-SYNC
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Error Due to Input RS Mismatch
vs Input Common Mode
(CIN >1µF)
200
R+ = 0k, R– = 1k
100
R+ = 0k, R– = 500Ω
R+ = 0k, R– = 100Ω
50
0
R+ = 100Ω, R– = 0k
R+ = 500Ω, R– = 0k
R+
–100
R+ =1k, R– = 0k
–
–150
100
R+ = 0k, R– = 1k
R+ = 0k, R– = 500Ω
R+ = 0k, R– = 100Ω
50
0
R+ = 100Ω, R– = 0k
50
R+ = 500Ω, R– = 0k
R+ =1k, R– = 0k
–150
R–
1.0
1.5
2.0
2.5
0.5
INPUT COMMON MODE VOLTAGE (V)
0
3.0
2
3
4
1
INPUT COMMON MODE VOLTAGE (V)
Offset Voltage vs Temperature
R+ = 0k, R– = 500Ω
50
R+ = 0k, R– = 100Ω
0
R+ = 100Ω, R– = 0k
–50
R+ = 500Ω, R– = 0k
–150
5
R+ =1k, R– = 0k
–5
–1
1
3
–3
INPUT COMMON MODE VOLTAGE (V)
30
60
VOS vs REF (Pin 5)
60
VIN+ = VIN– = REF
G = 10
TA = 25°C
20
5
2053 G21
VOS vs REF (Pin 5)
80
VIN+ = VIN– = REF
G = 10
TA = 25°C
40
40
VS = 5V
20
10
VS = ±5V
0
VS = 3V
–20
VOS (µV)
20
VOS (µV)
INPUT OFFSET VOLTAGE (µV)
R+ = 0k, R– = 1k
2053 G20
2053 G19
0
VS = 5V
VS = 3V
–10
0
VS = 10V
–20
–40
–40
–20
–60
–80
–50 –25
0
25
50
75
100
–30
125
–60
0
1
2
3
2053 G22
4
VS = ±2.5V
VREF = 0V
G=1
RL = 10k
TA = 25°C
2
0
–2
–4
–2
2053 G25
–10
–2.4
9
R+ = R– = 1k
R+ = R– = 10k
100
R+ = 10k, R– = 0k
90
–4
–8
8
110
0
–8
1.6
7
6
VS = 3V, 5V, ±5V
VIN = 1VP-P
120
2
–6
1.1
130
VS = ±2.5V
8 VREF = 0V
G = 10
6
RL = 10k
4 TA = 25°C
–6
–10
–2.4 –1.9 –1.4 –0.9 –0.4 0.1 0.6
OUTPUT VOLTAGE (V)
5
4
VREF (V)
CMRR vs Frequency
Gain Nonlinearity, G = 10
CMRR (db)
6
3
2
2053 G24
10
NONLINEARITY (ppm)
8
1
2053 G23
Gain Nonlinearity, G = 1
10
0
4
VREF (V)
TEMPERATURE (°C)
NONLINEARITY (ppm)
VS = ±5V
VREF = 0V
100 TA = 25°C
–100
–200
–200
0
150
–100
+
BIG CIN
150
VS = 5V
VREF = 0V
TA = 25°C
ADDITIONAL OFFSET ERROR (µV)
VS = 3V
150 VREF = 0V
TA = 25°C
ADDITIONAL OFFSET ERROR (µV)
ADDITIONAL OFFSET ERROR (µV)
200
–50
Error Due to Input RS Mismatch
vs Input Common Mode
(CIN >1µF)
Error Due to Input RS Mismatch
vs Input Common Mode
(CIN >1µF)
R+
+
80
–
R–
–1.4
0.6
–0.4
1.6
OUTPUT VOLTAGE (V)
2.6
2053 G26
70
1
R+ = 0k, R– = 10k
10
100
FREQUENCY (Hz)
1000
2053 G27
2053syncfb
7
LTC2053/LTC2053-SYNC
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Input Voltage Noise Density vs
Frequency
3
250
VS = ±5V
200
VS = 5V
150
VS = 3V
100
50
0
2
1
0
–1
–2
–3
1
10
100
1000
FREQUENCY (Hz)
3
VS = 3V
TA = 25°C
INPUT REFERRED NOISE VOLTAGE (µV)
G = 10
TA = 25°C
INPUT REFERRED NOISE VOLTAGE (µV)
INPUT REFERRED NOISE DENSITY (nV/√Hz)
300
Input Referred Noise in 10Hz
Bandwidth
Input Referred Noise in 10Hz
Bandwidth
10000
0
2
4
6
TIME (s)
Output Voltage Swing vs Output
Current
VS = 5V, SOURCING
VS = 3V, SOURCING
2.5
2.0
1.5
VS = 3V, SINKING
VS = 5V, SINKING
0.5
0
0.01
VS = ±5V
TA = 25°C
TA = 125°C
1
0
–1
–2
0.65
SINKING
1
0.1
OUTPUT CURRENT (mA)
0.60
2.5
10
0.1
2053 G34
6.5
8.5
SUPPLY VOLTAGE (V)
10.5
Internal Clock Frequency vs
Supply Voltage
3.40
VS = 5V
dVOUT = 1V
0.1% ACCURACY
TA = 25°C
25
3.35
20
15
10
0
3.30
TA = 125°C
3.25
TA = 85°C
3.20
3.15
5
1
4.5
2053 G33
CLOCK FREQUENCY (kHz)
2
TA = –55°C
–3
30
3
0.01
0.001
SETTLING ACCURACY (%)
TA = 0°C
0.75
0.70
35
4
TA = 85°C
0.80
Settling Time vs Gain
5
0
0.0001
0.85
2053 G32
VS = 5V
dVOUT = 1V
G < 100
TA = 25°C
10
8
0.90
–5
0.01
10
SETTLING TIME (ms)
SETTLING TIME (ms)
6
6
TIME (s)
0.95
2
Low Gain Settling Time vs
Settling Accuracy
7
4
3
2053 G31
8
2
SOURCING
–4
1
0.1
OUTPUT CURRENT (mA)
0
1.00
4
3.5
1.0
–2
Supply Current vs Supply Voltage
5
4.0
3.0
–1
2053 G30
SUPPLY CURRENT
TA = 25°C
0
Output Voltage Swing vs Output
Current
OUTPUT VOLTAGE SWING (V)
OUTPUT VOLTAGE SWING (V)
4.5
1
2053 G29
2053 G28
5.0
2
–3
10
8
VS = 5V
TA = 25°C
TA = 25°C
1
10
100
GAIN (V/V)
1000
10000
2053 G35
3.10
2.5
4.5
TA = –55°C
6.5
8.5
SUPPLY VOLTAGE (V)
10.5
2053 G36
2053syncfb
8
LTC2053/LTC2053-SYNC
U
U
W
U
APPLICATIO S I FOR ATIO
Settling Time
The sampling rate is 3kHz and the input sampling period
during which CS is charged to the input differential voltage
VIN is approximately 150µs. First assume that on each
input sampling period, CS is charged fully to VIN. Since CS
= CH (= 1000pF), a change in the input will settle to N bits
of accuracy at the op amp noninverting input after N clock
cycles or 333µs(N). The settling time at the OUT pin is also
affected by the settling of the internal op amp. Since the
gain bandwidth of the internal op amp is typically 200kHz,
the settling time is dominated by the switched capacitor
front end for gains below 100 (see Typical Performance
Characteristics).
Input Current
Whenever the differential input VIN changes, CH must be
charged up to the new input voltage via CS. This results in
an input charging current during each input sampling
period. Eventually, CH and CS will reach VIN and, ideally,
the input current would go to zero for DC inputs.
In reality, there are additional parasitic capacitors which
disturb the charge on CS every cycle even if VIN is a DC
voltage. For example, the parasitic bottom plate capacitor
on CS must be charged from the voltage on the REF pin to
the voltage on the –IN pin every cycle. The resulting input
charging current decays exponentially during each input
sampling period with a time constant equal to RSCS. If the
voltage disturbance due to these currents settles before
the end of the sampling period, there will be no errors
due to source resistance or the source resistance mismatch between –IN and +IN. With RS less than 10k, no
DC errors occur due to this input current.
In the Typical Performance Characteristics section of this
data sheet, there are curves showing the additional error
from non-zero source resistance in the inputs. If there are
no large capacitors across the inputs, the amplifier is less
sensitive to source resistance and source resistance mismatch. When large capacitors are placed across the inputs, the input charging currents described above result in
larger DC errors, especially with source resistor mismatches.
Power Supply Bypassing
The LTC2053 uses a sampled data technique and therefore
contains some clocked digital circuitry. It is therefore
sensistive to supply bypassing. For single or dual supply
operation, a 0.1µF ceramic capacitor must be connected
between Pin 8 (V +) and Pin 4 (V –) with leads as short as
possible.
SINGLE SUPPLY, UNITY GAIN
DUAL SUPPLY
5V
5V
8
V+IN
3
+
VD
V–IN
–
8
+
V+IN
7
2
6
–
5
VOUT
3
+
VD
V–IN
–
+
7
2
–
5
4
4
6 R2
VOUT
R1
–5V
VREF
0V < V+IN < 5V
0V < V–IN < 5V
0V < VD < 3.7V
VOUT = VD
–5V < V–IN < 5V AND ⏐V–IN – VREF⏐ < 5.5V
–5V < V+IN < 5V AND ⏐V+IN – VREF⏐ < 5.5V
–5V < VD + VREF < 3.7V
(
VOUT = 1 +
R2
R1
)
VD + VREF
2053 F01
Figure 1
2053syncfb
10
LTC2053/LTC2053-SYNC
U
U
W
U
APPLICATIO S I FOR ATIO
Synchronizing to an External Clock
(LTC2053-SYNC Only)
The LTC2053 has an internally generated sample clock
that is typically 3kHz. There is no need to provide the
LTC2053 with a clock. However, in some applications, it
may be desirable for the user to control the sampling
frequency more precisely to avoid undesirable aliasing.
This can be done with the LTC2053-SYNC. This device
uses PIN 1 as a clock input whereas the LTC2053 uses Pin
1 as an enable pin. If CLK (PIN 1) is left floating on the
LTC2053-SYNC, the device will run on its internal oscillator, similar to the LTC2053. However, if not externally
synchronizing to a system clock, it is recommended that
the LTC2053 be used instead of the LTC2053-SYNC
because the LTC2053-SYNC is sensitive to parasitic capacitance on the CLK pin when left floating. Clocking the
LTC2053-SYNC is accomplished by driving the CLK pin
at 8 times the desired sample clock frequency. This
completely disables the internal clock. For example, to
achieve the nominal LTC2053 sample clock rate of 3kHz,
a 24kHz external clock should be applied to the CLK pin
of the LTC2053-SYNC. If a square wave is used to drive the
CLK pin, a 5µs RC time constant should be placed in front
of the CLK pin to maintain low offset voltage performance
(see Figure 2). This avoids internal and external coupling
of the high frequency components of the external clock at
the instant the LTC2053-SYNC holds the sampled input.
The LTC2053-SYNC is tested with a sample clock of 3kHz
(fCLK = 24kHz) to the same specifications as the LTC2053.
In addition the LTC2053-SYNC is tested at 1/2 and 2X this
frequency to verify proper operation. The curves in the
Typical Performance Characteristics section of this
datasheet apply to the LTC2053-SYNC when driving it with
a 24kHz clock at PIN1 (fCLK = 24kHz, 3kHz sample clock
rate). Below are three curves that show the behavior of the
LTC2053-SYNC as the clock frequency is varied. The
offset is essentially unaffected over a 2:1 increase or
decrease of the typical LTC2053 sample clock speed. The
bias current is directly proportional to the clock speed. The
noise is roughly proportional to the square root of the
clock frequency. For optimum noise and bias current
performance, drive the LTC2053-SYNC with a nominal
24kHz external clock (3kHz sample clock).
1kΩ
5V
8
3
V+IN
+
VD
–
V–IN
4.7nF
1
+
CLK
2
LTC2053-SYNC
EXTERNAL
CLOCK
–
5
4
5V
0V
7
6 R2
VOUT
R1
2053 F02
Figure 2
20
14
15
12
INPUT BIAS CURRENT (nA)
VS = ±5V
10
INPUT OFFSET (µV)
LTC2053-SYNC
Average Input Bias Current
vs Sample Frequency
5
0
VS = 5V
–5
VS = 3V
–10
Typ LTC2053 Sample Frequency
–15
–20
LTC2053-SYNC
Input Referred Noise
vs Sample Frequency
12
VS = 5V
VREF = 0
VCM = 1V
10
8
6
4
Typ LTC2053 Sample Frequency
2
0
0
4000
6000
8000 10000
2000
SAMPLE FREQUENCY (Hz) (=FCLK/8)
2053 F03
0
4000
6000
8000 10000
2000
SAMPLE FREQUENCY (Hz) (=FCLK/8)
2053 F04
INPUT REFERRED NOISE VOLTAGE (µVPP)
LTC2053-SYNC
Input Offset
vs Sample Frequency
VS = 5V
TA = 25°C
Noise in 10Hz Bandwidth
10
8
Typ LTC2053 Sample Frequency
6
4
2
0
0
4000
6000
8000
2000
SAMPLE FREQUENCY (FCLK/8)
10000
2053 F05
2053syncfb
11
LTC2053/LTC2053-SYNC
U
TYPICAL APPLICATIO S
Precision ÷2
(Low Noise 2.5V Reference)
Precision Current Source
8V
5V
0.1µF
2
–
8
1 LT1027 4
–5
2
1µF
8
7
LTC2053 RG
REF 6 0.1µF
3 +
5
EN
4
1
R
VOUT
i
3
+
–
1
4
5
6
0.1µF
2053 TA03
0 < VOUT < (5V – VC)
VC
2.5V
(110nV/√Hz)
1k
V
i = —C , i ≤ 5mA
R
10k
7
LTC2053
2
2.7k
LOAD
8
0.1µF
2053 TA02
Precision Doubler
(General Purpose)
5V
VIN
3
+
5V
0.1µF
3
8
7
LTC2053
2
Precision Inversion
(General Purpose)
–
4
1
5
+
8
7
LTC2053
VOUT
6
0.1µF
VIN
2
–
1
4
5
VOUT
6
VOUT = 2VIN
0.1µF
0.1µF
VOUT = –VIN
0.1µF
–5V
2053 TA04
–5V
2053 TA05
2053syncfb
12
LTC2053/LTC2053-SYNC
5V
10M
0°C → 500°C
TYPE K
THERMOCOUPLE
(40.6µV/°C)
YELLOW
+
ORANGE
–
1M
10M
1M
0.1µF
10k
3
10k 2
0.001µF
1
0.001µF
8
+
LTC2053
–
RG
REF
5
EN
7
10mV/°C
6
249k
1%
4
0.1µF
100Ω
THERMAL
COUPLING
5V
0.1µF
1k
1%
5V
2
LT1025
3
VO
–
R
4
5 200k
4
–
6
LTC2050
3
+
1
SCALE FACTOR
TRIM
2
2053 TA06
2053syncfb
13
LTC2053/LTC2053-SYNC
U
PACKAGE DESCRIPTIO
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
0.889 ± 0.127
(.035 ± .005)
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.65
(.0256)
BSC
0.42 ± 0.038
(.0165 ± .0015)
TYP
8
7 6 5
0.52
(.0205)
REF
RECOMMENDED SOLDER PAD LAYOUT
0.254
(.010)
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
4.90 ± 0.152
(.193 ± .006)
DETAIL “A”
0° – 6° TYP
GAUGE PLANE
1
0.53 ± 0.152
(.021 ± .006)
DETAIL “A”
2 3
4
1.10
(.043)
MAX
0.86
(.034)
REF
0.18
(.007)
SEATING
PLANE
0.22 – 0.38
(.009 – .015)
TYP
0.65
(.0256)
BSC
0.127 ± 0.076
(.005 ± .003)
MSOP (MS8) 0204
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
2053syncfb
14
LTC2053/LTC2053-SYNC
U
PACKAGE DESCRIPTIO
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
0.675 ±0.05
3.5 ±0.05
1.65 ±0.05
2.15 ±0.05 (2 SIDES)
PACKAGE
OUTLINE
0.25 ± 0.05
0.50
BSC
2.38 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
R = 0.115
TYP
5
3.00 ±0.10
(4 SIDES)
0.38 ± 0.10
8
1.65 ± 0.10
(2 SIDES)
PIN 1
TOP MARK
(NOTE 6)
(DD8) DFN 1203
0.200 REF
0.75 ±0.05
0.00 – 0.05
4
0.25 ± 0.05
1
0.50 BSC
2.38 ±0.10
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
2053syncfb
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
LTC2053/LTC2053-SYNC
U
TYPICAL APPLICATIO
Linearized Platinum RTD Amplifier
5V 0.1µF
2
–
1.21k
8
7
LTC2053
3
*CONFORMING TO IEC751 OR DIN43760
RT = RO (1 + 3.908 • 10–3T – 5.775 • 10–7T2), RO = 100Ω
(e.g. 100Ω AT 0°C, 175.9Ω AT 200°C, 247.1Ω AT 400°C)
+
1
4
6
5
0.1µF
5V
2.7k
16.9k
10k
i ≈ 1mA
5V
2
–
0.1µF
3
+
PT100*
3-WIRE RTD
1
4
49.9Ω
7
LTC2053
6
5
LT1634-1.25
249k
8
1M
0.1µF
10mV/°C
0°C – 400°C
(±0.1°C)
16.2k
11k
CW
LINEARITY
10k
39.2k
100Ω
ZERO
CW
0.1µF
GAIN CW
24.9k
953Ω
5k
2053 TA08
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
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Single Gain Set Resistor: G = 1 to 10,000,
Low Noise: 7.5nV√Hz
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SOT-23/MS8 Package
LTC2054/LTC2055 Zero-Drift µPower Operational Amplifier
SOT-23/MS8 Package, 150µA/OP Amp
LTC6800
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Single Supply, Zero Drift, Rail-to-Rail Input and Output Instrumentation
Amplifier
2053syncfb
16
Linear Technology Corporation
LT/TP 0205 Rev B 1K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
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