OPA2387DGKT [TI]
OPA2387 Ultra-High Precision, Zero-Drift, Low-Input-Bias-Current Op Amps;
| 型号： | OPA2387DGKT |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | OPA2387 Ultra-High Precision, Zero-Drift, Low-Input-Bias-Current Op Amps |
| 文件： | 总26页 (文件大小：2072K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
OPA2387
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
OPA2387 Ultra-High Precision, Zero-Drift, Low-Input-Bias-Current Op Amps
1 Features
3 Description
•
•
•
•
•
•
Ultra-low offset voltage: ±2 µV (maximum, tested)
Zero drift: ±0.003 µV/°C
The OPA387, OPA2387, and OPA4387 (OPAx387)
family of precision amplifiers offers state-of-the-art
performance. With zero-drift technology, the OPAx387
offset voltage and offset drift provide unparalleled
long-term stability. With a mere 570 µA of quiescent
current, the OPAx387 are able to achieve 5.7 MHz of
bandwidth, a broadband noise of 8.5 nV/√Hz, and a
1/f noise at 177 nVPP. These specifications are crucial
to achieve extremely-high precision and no
degradation of linearity in 16-bit to 24-bit analog to
digital converters (ADCs). The OPAx387 feature flat
bias current over temperature; therefore, little to no
calibration is needed in high input impedance
applications over temperature.
Low-input bias current: 135 pA (maximum, tested)
Low noise: 8.5 nV√Hz at 1 kHz
No 1/f noise: 177 nVPP (0.1 Hz to 10 Hz)
Common-mode input range ±100 mV beyond
supply rails
Gain bandwidth: 5.7 MHz
Quiescent current: 570 μA per amplifier
Single supply: 1.7 V to 5.5 V
•
•
•
•
•
Dual supply: ±0.85 V to ±2.75 V
EMI/RFI filtered inputs
2 Applications
All versions are specified over the industrial
temperature range of –40°C to +125°C.
•
•
•
•
•
•
•
•
•
•
Electronic thermometer
Weigh scale
Temperature transmitter
Ventilators
Data acquisition (DAQ)
Semiconductor test
Lab and field instrumentation
Merchant network and server PSU
Analog input module
Pressure transmitter
Device Information
PART NUMBER
PACKAGE(1)
BODY SIZE (NOM)
2.90 mm × 1.60 mm
1.50 mm × 1.50 mm
4.90 mm × 3.90 mm
3.00 mm × 3.00 mm
2.00 mm × 2.00 mm
5.00 mm × 4.40 mm
SOT-23 (5)(3)
OPA387(2)
DFN (6)(3)
SOIC (8)(3)
VSSOP (8)
DFN (8)(3)
OPA2387
OPA4387(2)
TSSOP (14)(3)
(1) For all available packages, see the package option
addendum at the end of the data sheet.
(2) Device is preview.
(3) Package is preview.
50
45
40
35
30
25
20
15
10
5
ADC
OPA387
Radiation
Detector
OPA387 as an Ultra-Low Offset, Low-Noise ADC
Driver
0
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Input Offset Voltage (mV)
c110
Ultra-Low Input Offset Voltage
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
Table of Contents
1 Features............................................................................1
2 Applications.....................................................................1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Pin Configuration and Functions...................................3
6 Specifications.................................................................. 4
6.1 Absolute Maximum Ratings ....................................... 4
6.2 ESD Ratings .............................................................. 4
6.3 Recommended Operating Conditions ........................4
6.4 Thermal Information ...................................................4
6.5 Electrical Characteristics ............................................5
6.6 Typical Characteristics................................................7
7 Detailed Description......................................................12
7.1 Overview...................................................................12
7.2 Functional Block Diagram.........................................12
7.3 Feature Description...................................................13
7.4 Device Functional Modes..........................................13
8 Application and Implementation..................................14
8.1 Application Information............................................. 14
8.2 Typical Applications.................................................. 14
9 Power Supply Recommendations................................17
10 Layout...........................................................................17
10.1 Layout Guidelines................................................... 17
10.2 Layout Example...................................................... 17
11 Device and Documentation Support..........................18
11.1 Device Support........................................................18
11.2 Documentation Support.......................................... 18
11.3 Receiving Notification of Documentation Updates..18
11.4 Support Resources................................................. 18
11.5 Trademarks............................................................. 18
11.6 Electrostatic Discharge Caution..............................18
11.7 Glossary..................................................................18
12 Mechanical, Packaging, and Orderable
Information.................................................................... 19
4 Revision History
Changes from Revision * (November 2020) to Revision A (December 2020)
Page
•
Changed OPA2387 from advanced information (preview) to production data (active).......................................1
Copyright © 2020 Texas Instruments Incorporated
2
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
5 Pin Configuration and Functions
OUT A
œIN A
+IN A
Vœ
1
2
3
4
8
7
6
5
V+
OUT B
œIN B
+IN B
Not to scale
Figure 5-1. DGK Package, 8-Pin VSSOP, Top View
Table 5-1. Pin Functions
PIN
I/O
DESCRIPTION
NAME
NO.
2
–IN A
–IN B
+IN A
+IN B
I
I
Inverting input, channel A
Inverting input, channel B
Noninverting input, channel A
Noninverting input, channel B
Output, channel A
6
3
I
5
I
OUT A
OUT B
V–
1
O
O
—
—
7
Output, channel B
4
Negative (lowest) power supply
Positive (highest) power supply
V+
8
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
3
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
MIN
MAX
UNIT
Single-supply
6
VS
Supply Voltage, VS = (V+) – (V–)
Input voltage, all pins
V
Dual-supply
Common-mode
Differential
±3
(V+) + 0.5
(V+) – (V–) + 0.2
±10
(V–) – 0.5
V
Input current, all pins
Output short circuit(2)
Operating temperature
Junction temperature
Storage temperature
mA
Continuous
–55
Continuous
150
TA
°C
°C
°C
TJ
–55
150
Tstg
–65
150
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under
Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device
reliability.
(2) Short-circuit to ground, one amplifier per package.
6.2 ESD Ratings
VALUE
±3000
±1000
UNIT
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)
V(ESD)
Electrostatic discharge
V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2)
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
1.7
NOM
MAX
5.5
UNIT
V
Single-supply
Dual-supply
VS
TA
Supply voltage, VS = (V+) – (V–)
Specified temperature
±0.85
–40
±2.75
125
°C
6.4 Thermal Information
OPA2387
THERMAL METRIC(1)
DGK (VSSOP)
UNIT
8 PINS
165
53
RθJA
Junction-to-ambient thermal resistance
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
RθJC(top)
RθJB
Junction-to-case (top) thermal resistance
Junction-to-board thermal resistance
87
ΨJT
Junction-to-top characterization parameter
Junction-to-board characterization parameter
Junction-to-case (bottom) thermal resistance
4.9
ΨJB
85
RθJC(bot)
N/A
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
Copyright © 2020 Texas Instruments Incorporated
4
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.5 Electrical Characteristics
at TA = 25°C, RL = 10 kΩ connected to VS / 2, VS = 1.7 V to 5.5 V, VCM = VS / 2, VOUT = VS / 2, and min and max specification
established from manufacturing final test (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
OFFSET VOLTAGE
VS = 5.5 V
±1
±1.5
±2
TA = –40°C to +125°C(1)
VS = 5.5 V
±0.25
±0.35
VOS
Input offset voltage
µV
VS = 1.7 V
±2.5
±2
VCM = (V–) – 0.1(1)
VCM = (V+) + 0.1(1)
±2
dVOS/dT
PSRR
Input offset voltage drift TA = –40°C to +125°C(1)
±0.003
±0.05
±0.012
±0.35
±1
μV/°C
μV/V
Power supply rejection
VS = 1.7 V to 5.5 V
ratio
TA = –40°C to +125°C(1)
INPUT BIAS CURRENT
±30
±60
±135
±135
±270
±270
IB
Input bias current
pA
pA
TA = –40°C to +125°C(1)
TA = –40°C to +125°C(1)
IOS
Input offset current
Input voltage noise
NOISE
177
27
nVPP
f = 0.1 Hz to 10 Hz
nVRMS
f = 1 Hz
8.5
8.5
8.5
8.5
70
f = 10 Hz
f = 100 Hz
f = 1 kHz
f = 1 kHz
Input voltage noise
density
eN
nV/√Hz
fA/√Hz
V
iN
Input current noise
INPUT VOLTAGE RANGE
VS = 1.7 V
VS = 5.5 V
(V–) – 0.1
(V–) – 0.2
115
(V+)
Common-mode voltage
range
VCM
(V+) + 0.1
(V–) – 0.1 V < VCM < (V+), VS = 1.7 V
138
150
132
(V–) – 0.2 V < VCM < (V+) + 0.1 V, VS = 5.5 V
(V–) – 0.1 V < VCM < (V+), TA = –40°C to +125°C(1)
140
Common-mode
rejection ratio
CMRR
dB
110
(V–) – 0.2 V < VCM < (V+) + 0.1, VS = 5.5 V,
TA = –40°C to +125°C(1)
130
INPUT CAPACITANCE
ZID
Differential
100 || 3
60 || 3
MΩ || pF
GΩ || pF
ZICM
Common-mode
OPEN-LOOP GAIN
(V–) + 100 mV < VOUT
(V+) – 100 mV,
RL = 10 kΩ
<
<
132
125
132
125
145
145
TA = –40°C to +125°C(1)
TA = –40°C to +125°C(1)
AOL
Open-loop voltage gain
dB
(V–) + 150 mV < VOUT
(V+) – 150 mV,
RL = 2 kΩ
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
5
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.5 Electrical Characteristics (continued)
at TA = 25°C, RL = 10 kΩ connected to VS / 2, VS = 1.7 V to 5.5 V, VCM = VS / 2, VOUT = VS / 2, and min and max specification
established from manufacturing final test (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
FREQUENCY RESPONSE
Gain-bandwidth
product
GBW
5.7
MHz
V/μs
SR
tS
Slew rate
4-V step, G = +1
2.8
1.5
2.5
500
To 0.1%, 1-V step , G = +1
To 0.01%, 1-V step , G = +1
Settling time
μs
Overload recovery time VIN × gain > VS
ns
Chopping clock
frequency(1)
100
150
kHz
Total harmonic
distortion + noise
THD+N
VOUT = 1 VRMS, G = +1, f = 1 kHz, RL = 10 kΩ
0.002 %
OUTPUT
TA = 25°C, no load
1
5
10
30
60
30
TA = 25°C, RL = 10 kΩ
Voltage output swing
from rail
mV
TA = 25°C, RL = 2 kΩ
20
RL = 10 kΩ, TA = –40°C to +125°C(1)
(V–) +
0.075
(V+) –
0.075
AOL > 120 dB, RL = 10 kΩ
AOL > 120 dB, RL = 2 kΩ
V
V
High linearity output
swing range(1)
(V–) +
0.075
(V+) –
0.075
VS = 5.5 V
±55
±25
40
mA
mA
ISC
Short-circuit current
Phase margin
VS = 1.7 V
CL = 100 pF, gain = +1
degrees
POWER SUPPLY
570
25
675
700
μA
μA
Quiescent current per
amplifier
IQ
IO = 0 mA
TA = –40°C to 125°C(1)
At TA = 25°C, VS = 5.5 V,
VS ramp rate > 0.3 V/µs, settle to 1%
Turn-on time
100
μs
(1) Specification established from device population bench system measurements across multiple lots.
Copyright © 2020 Texas Instruments Incorporated
6
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.6 Typical Characteristics
at TA = 25°C, VS = ±2.5 V, VCM = VS / 2, RLOAD = 10 kΩ connected to VS / 2, and CL = 50 pF (unless otherwise noted)
50
45
40
35
30
25
20
15
10
5
60
55
50
45
40
35
30
25
20
15
10
5
0
-2
0
-1.5
-1
-0.5
0
0.5
1
1.5
2
-5
-4
-3
-2
-1
0
1
2
3
4
5
Input Offset Voltage (mV)
Input Offset Voltage (mV)
c110
c100
VS = 5.5 V
VS = 5.5 V
Figure 6-1. Offset Voltage Distribution, 25°C
Figure 6-2. Offset Voltage Distribution, –40°C
40
35
30
25
20
15
10
5
60
50
40
30
20
10
0
0
-5
-4
-3
-2
-1
0
1
2
3
4
5
-0.02
-0.01
0
0.01
0.02
Input Offset Voltage (mV)
Offset Voltage Drift (mV/èC)
c101
c103
VS = 5.5 V
VS = 5.5 V
Figure 6-3. Offset Voltage Distribution, 125°C
Figure 6-4. Offset Voltage Drift Distribution
3
2
3
2
1
1
VCM = -2.95 V
VCM = 2.85 V
0
0
-1
-2
-3
-1
-2
-3
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (èC)
-3
-2
-1
0
Input Common Mode Voltage (V)
1
2
3
c108
c111
Figure 6-5. Offset Voltage vs Temperature
Figure 6-6. Offset Voltage vs Common-Mode Voltage
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
7
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.6 Typical Characteristics (continued)
at TA = 25°C, VS = ±2.5 V, VCM = VS / 2, RLOAD = 10 kΩ connected to VS / 2, and CL = 50 pF (unless otherwise noted)
1
0.75
0.5
160
140
120
100
80
165
150
135
120
105
90
Gain
Phase
0.25
0
60
-0.25
-0.5
-0.75
-1
40
75
20
60
Vs = 1.7 V
0
45
-20
30
1.5
2
3
Supply Voltage (V)
4
5
5.5
100m
1
10
100
1k
Frequency (Hz)
10k
100k
1M
10M
c112
c114
Figure 6-7. Offset Voltage vs Supply Voltage
Figure 6-8. Open-Loop Gain and Phase vs Frequency
0.5
0.25
0
60
VS = ê0.85 V
VS = ê2.75 V
40
20
0
-20
-0.25
G = -1
G = +1
-40
-60
G = +10
G = +100
-0.5
-75
-50
-25
0
25
50
75
100 125 150
100
1k
10k 100k
Frequency (Hz)
1M
10M
Temperature(èC)
C129
c113
Figure 6-9. Open-Loop Gain vs Temperature
Figure 6-10. Closed-Loop Gain and Phase vs Frequency
0.1
0.08
0.06
0.04
0.02
0
160
CMRR
PSRR-
PSRR+
140
120
100
80
VS = ê2.75 V, (V-) - 0.2 V Ç VCM Ç (V+) + 0.1 V
-0.02
-0.04
-0.06
-0.08
-0.1
60
40
VS = ê0.85 V, (V-) - 0.1 V Ç VCM Ç (V+)
20
0
10m 100m
-75
-50
-25
0
25
50
75
100 125 150
1
10
100 1k
Frequency (Hz)
10k 100k 1M 10M
Temperature (èC)
C121
C134
Figure 6-11. CMRR vs Temperature
Figure 6-12. PSRR and CMRR vs Frequency
Copyright © 2020 Texas Instruments Incorporated
8
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.6 Typical Characteristics (continued)
at TA = 25°C, VS = ±2.5 V, VCM = VS / 2, RLOAD = 10 kΩ connected to VS / 2, and CL = 50 pF (unless otherwise noted)
20
10
7
5
4
3
2
1
100m
1
10
100
Frequency (Hz)
1k
10k
100k
Time (1 s/div)
C130
c115
Figure 6-13. 0.1-Hz to 10-Hz Noise
Figure 6-14. Input Voltage Noise Spectral Density vs Frequency
0.1
-60
-40
-60
G = -1, RL = 10 kW
G = -1, RL = 2 kW
G = -1, RL = 600 W
G = +1, RL = 10 kW
G = +1, RL = 2 kW
G = +1, RL = 600 W
-80
0.01
-80
-100
-120
-140
-160
-180
-200
0.001
0.0001
-100
-120
20k
20
200
2k
Frequency (Hz)
C137
100
1k
10k 100k
Frequency (Hz)
1M
10M
C122
VS = 5.5 V, VOUT = 3 VRMS, BW = 80 kHz
Figure 6-15. Channel-to-Channel Crosstalk
Figure 6-16. THD+N Ratio vs Frequency
1
-40
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
G = -1, RL = 10 kW
G = -1, RL = 2 kW
G = -1, RL = 600 W
G = +1, RL = 10 kW
G = +1, RL = 2 kW
G = +1, RL = 600 W
0.1
0.01
-60
-80
0.001
-100
-120
0.0001
10m
100m
Output Amplitude (VRMS
1
)
C136
1
2
3
Supply Voltage (V)
4
5
6
c107
VS = 5.5 V, f = 1 kHz, BW = 80 kHz
Figure 6-17. THD+N vs Output Amplitude
Figure 6-18. Quiescent Current vs Supply Voltage
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
9
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.6 Typical Characteristics (continued)
at TA = 25°C, VS = ±2.5 V, VCM = VS / 2, RLOAD = 10 kΩ connected to VS / 2, and CL = 50 pF (unless otherwise noted)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
1000
100
10
1
0.1
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (èC)
1
10
100
1k 10k
Frequency (Hz)
100k
1M
10M
c102
C138
Figure 6-19. Quiescent Current vs Temperature
Figure 6-20. Open-Loop Output Impedance vs Frequency
80
60
40
20
0
80
RISO = 0 W
RISO = 25 W
RISO = 50 W
RISO = 0 W
RISO = 25 W
RISO = 50 W
60
40
20
0
100
Load Capacitance (pF)
1k
100
Load Capacitance (pF)
1k
C124
C127
G = –1, 10 mV step
G = +1, 10 mV step
Figure 6-21. Small-Signal Overshoot vs Capacitive Load
Figure 6-22. Small-Signal Overshoot vs Capacitive Load
60
VIN
VOUT
45
30
15
0
100
Load Capacitance (pF)
1k
Time (100 µs/div)
C125
C132
Figure 6-24. No Phase Reversal
Figure 6-23. Phase Margin vs Capacitive Load
Copyright © 2020 Texas Instruments Incorporated
10
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
6.6 Typical Characteristics (continued)
at TA = 25°C, VS = ±2.5 V, VCM = VS / 2, RLOAD = 10 kΩ connected to VS / 2, and CL = 50 pF (unless otherwise noted)
VIN
VOUT
VIN
VOUT
Time (500 ns/div)
Time (1 µs/div)
C133
C128
G = –1
G = +1
Figure 6-25. Overload Recovery
Figure 6-26. Small-Signal Step Response
VIN
VOUT
Rising Edge
Falling Edge
Time (1 µs/div)
Time (10 µs/div)
c105
C135
0.01% settling = ±100 µV
Figure 6-27. Large-Signal Step Response (4-V Step)
Figure 6-28. Settling Time
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
11
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
7 Detailed Description
7.1 Overview
The OPAx387 family of zero-drift amplifiers is engineered with state-of-the-art, proprietary, precision zero-drift
technology. These amplifiers offer ultra-low input offset voltage and drift, and achieve excellent input and output
dynamic linearity. The OPAx387 operate from 1.7 V to 5.5 V, are unity-gain stable, and are designed for a wide
range of general-purpose and precision applications. The OPAx387 strengths also include a 5.7-MHz bandwidth,
8.5-nV/√Hz noise spectral density, and no 1/f noise, making the OPAx387 an excellent choice for interfacing with
sensor modules, and buffering high-fidelity, digital-to-analog converters (DACs).
7.2 Functional Block Diagram
GM_FF
CCOMP
CLK
CLK
+IN
OUT
œIN
GM1
GM2
GM3
CCOMP
Ripple Reduction
Technology
Copyright © 2020 Texas Instruments Incorporated
12
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
7.3 Feature Description
7.3.1 Input Bias Current
During normal operation, the typical input bias current of the OPAx387 is 30 pA. The device exhibits low drift
over the full temperature range of –40°C to +125°C. There are no antiparallel diodes between the input pins (+IN
and –IN); therefore, the differential input maximum voltage is limited only by diodes connected to the supply
voltage pins. However, use caution in cases where the input differential voltage exceeds the nominal operating
input differential voltage. When inputs are separated, the switching offset-cancellation path internal to the
amplifier exceeds normal operating conditions, and can potentially create long settling behavior upon return to
normal operation. The equivalent input circuit of OPAx387 is shown in Figure 7-1.
V+
450 ꢀ
+IN
œ
CORE
450 ꢀ
œIN
+
Vœ
Figure 7-1. Equivalent Input Circuit
7.3.2 EMI Susceptibility and Input Filtering
Operational amplifiers can exhibit sensitivity to electromagnetic interference (EMI). Typically, conducted EMI
(that is, EMI that enters the device through conduction) is more commonly observed than radiated EMI (that is,
EMI that enters the device through radiation). When conducted EMI enters the operational amplifier, the dc offset
at the amplifier output can shift from the nominal value. This shift is a result of signal rectification associated with
the internal semiconductor junctions. Although all operational amplifier pin functions can be affected by EMI, the
input pins are likely to be the most susceptible. The OPAx387 operational amplifier family incorporates an
internal input low-pass filter that reduces the amplifier response to EMI. Both common-mode and differential-
mode filtering are provided by the input filter. The conducted EMI rejection of the OPAx387 is seen in Figure 7-2.
140
130
120
110
100
90
80
70
60
50
40
30
20
10M
100M
Frequency (Hz)
1G
5G
c104
Figure 7-2. EMI Rejection Ratio
7.4 Device Functional Modes
The OPAx387 has a single functional mode and is operational when the power-supply voltage is greater than
1.7 V (±0.85 V). The maximum specified power-supply voltage for the OPAx387 is 5.5 V (±2.75 V).
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
13
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
8 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification, and TI
does not warrant its accuracy or completeness. TI’s customers are responsible for determining
suitability of components for their purposes, as well as validating and testing their design
implementation to confirm system functionality.
8.1 Application Information
The OPAx387 are unity-gain stable, precision, operational amplifiers featuring state-of-the-art, zero-drift
technology. The use of proprietary zero-drift circuitry gives the benefit of low input offset voltage over time and
temperature, as well as lower 1/f noise component. As a result of the high PSRR, the devices work well in
applications that run directly from battery power without regulation. The OPAx387 family is optimized for full rail-
to-rail input, allowing for low-voltage, single-supply operation or split-supply use. These miniature, high-precision,
low-noise amplifiers offer high-impedance inputs that have a common-mode range 100 mV beyond the supplies
without input crossover distortion, and a rail-to-rail output that swings within 5 mV of the supplies under normal
test conditions. The OPAx387 precision amplifiers are designed for upstream analog signal-chain applications in
low or high gains, as well as downstream signal-chain functions, such as DAC buffering.
8.1.1 Zero-Drift Clocking
The OPAx387 use an advanced zero-drift architecture to achieve ultra-low offset and offset drift. This
architecture uses a clock and switches internally to create a dc error-correction path. The clocking is filtered
internally, and typically not observable for most configurations. Take the following precautions to minimize clock
noise in the signal chain. The clocking creates a small charge-injection pulse at the input of the amplifier;
therefore, do not use high-value resistors (> 100 kΩ) in series with the inputs to avoid higher clock voltage noise
at the output. The charge injection pulses are minimized when the impedance to the input pins is matched. If
higher value resistors are used, then use matching impedances on both amplifier input pins.
8.2 Typical Applications
8.2.1 Bidirectional Current Sensing
This single-supply, low-side, bidirectional current-sensing design example detects load currents from –1 A to +1
A. The single-ended output spans from 110 mV to 3.19 V. This design uses the OPAx387 because of the device
low offset voltage and rail-to-rail input and output. One of the amplifiers is configured as a difference amplifier
and the other amplifier provides the reference voltage. Figure 8-1 shows the design example schematic.
VCC
VREF
VCC
R5
+
U1B
ILOAD
R6
R2
+
R1
+
VBUS
+
œ
VSHUNT
RSHUNT
VOUT
U1A
VCC
R4
R3
œ
RL
Figure 8-1. Bidirectional Current-Sensing Schematic
Copyright © 2020 Texas Instruments Incorporated
14
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
8.2.1.1 Design Requirements
This solution has the following requirements:
•
•
•
Supply voltage: 3.3 V
Input: –1 A to +1 A
Output: 1.65 V ±1.54 V (110 mV to 3.19 V)
8.2.1.2 Detailed Design Procedure
The load current, ILOAD, flows through the shunt resistor, RSHUNT, to develop the shunt voltage, VSHUNT. The
shunt voltage is then amplified by the difference amplifier consisting of U1A and R1 through R4. The gain of the
difference amplifier is set by the ratio of R4 to R3. To minimize errors, set R2 = R4 and R1 = R3. The reference
voltage, VREF, is supplied by buffering a resistor divider using U1B. The transfer function is given by Equation 1.
VOUT = VSHUNT ´ GainDiff_Amp + VREF
(1)
where
VSHUNT = ILOAD ´ RSHUNT
•
R4
GainDiff_Amp
=
R3
•
R6
R5 + R6
VREF = VCC
´
•
There are two types of errors in this design: gain and offset. Gain errors are introduced by the tolerance of the
shunt resistor and the ratios of R4 to R3 and, similarly, R2 to R1. Offset errors are introduced by the voltage
divider (R5 and R6) and how closely the ratio of R4 / R3 matches R2 / R1. The latter value affects the CMRR of
the difference amplifier, ultimately translating to an offset error.
The value of VSHUNT is the ground potential for the system load because VSHUNT is a low-side measurement.
Therefore, a maximum value must be placed on VSHUNT. In this design, the maximum value for VSHUNT is set to
100 mV. Equation 2 calculates the maximum value of the shunt resistor given a maximum shunt voltage of
100 mV and maximum load current of 1 A.
VSHUNT(Max)
100 mV
= 100 mW
RSHUNT(Max)
=
=
ILOAD(Max)
1 A
(2)
The tolerance of RSHUNT is directly proportional to cost. For this design, a shunt resistor with a tolerance of 0.5%
was selected. If greater accuracy is required, select a 0.1% resistor or better.
The load current is bidirectional; therefore, the shunt voltage range is –100 mV to +100 mV. This voltage is
divided down by R1 and R2 before reaching the operational amplifier, U1A. Make sure that the voltage present at
the noninverting node of U1A is within the common-mode range of the device. Use an operational amplifier, such
as the OPAx387, that has a common-mode range that extends below the negative supply voltage. The offset
error is minimal because the OPAx387 has a typical offset voltage of merely ±0.25 µV (±5 µV, maximum).
Given a symmetric load current of –1 A to +1 A, the voltage divider resistors, R5 and R6, must be equal. To be
consistent with the shunt resistor, a tolerance of 0.5% is selected. To minimize power consumption, 10‑kΩ
resistors are used.
To set the gain of the difference amplifier, the common-mode range and output swing of the OPAx387 must be
considered. Equation 3 and Equation 4 depict the typical common-mode range and maximum output swing,
respectively, of the OPAx387 given a 3.3‑V supply.
–100 mV < VCM < 3.4 V
100 mV < VOUT < 3.2 V
(3)
(4)
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
15
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
The gain of the difference amplifier can now be calculated as shown in Equation 5.
V
OUT_Max - VOUT_Min
3.2 V - 100 mV
100 mW ´ [1 A - (- 1A)]
V
V
= 15.5
=
GainDiff_Amp
=
R
SHUNT ´ (IMAX - IMIN
)
(5)
The resistor value selected for R1 and R3 was 1 kΩ. 15.4 kΩ was selected for R2 and R4 because this number is
the nearest standard value. Therefore, the ideal gain of the difference amplifier is 15.4 V/V.
The gain error of the circuit primarily depends on R1 through R4. As a result of this dependence, 0.1% resistors
were selected. This configuration reduces the likelihood that the design requires a two-point calibration. A simple
one-point calibration, if desired, removes the offset errors introduced by the 0.5% resistors.
8.2.1.3 Application Curve
3.30
1.65
0
-1.0
-0.5
0
0.5
1.0
Input Current (A)
Figure 8-2. Bidirectional Current-Sensing Circuit Performance: Output Voltage vs Input Current
8.2.2 Load Cell Measurement
Figure 8-3 shows the OPAx387 in a high-CMRR dual-op amp instrumentation amplifier with a trim resistor and 6-
wire load cell for precision measurement.
R3
25 kꢀ
R4
100 kꢀ
5 V
REF5025
RG
R4
R2
100 kꢀ
25 kꢀ
5 V
5 V
5 V
+SENSE
œ
OPAx387
œ
OPAx387
VOUT
+
+
R2
GND
GND
10 kꢀ
œSENSE
200 kΩ
Load Cell
G = 5 +
GND
RG
GND
Figure 8-3. Load Cell Measurement Schematic
Copyright © 2020 Texas Instruments Incorporated
16
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
9 Power Supply Recommendations
The OPAx387 family of devices is specified for operation from 1.7 V to 5.5 V for single supplies, and ±0.85 V to
±2.75 V for dual supplies. Key parameters that can exhibit significant variance with regard to operating voltage
are presented in Section 6.6.
CAUTION
Supply voltages greater than 6 V can permanently damage the device (see Section 6.1).
10 Layout
10.1 Layout Guidelines
Pay attention to good layout practice. Keep traces short and, when possible, use a printed-circuit board (PCB)
ground plane with surface-mount components placed as close to the device pins as possible. Place a 0.1-µF
capacitor close to the supply pins. These guidelines must be applied throughout the analog circuit to improve
performance, and provide benefits such as reducing the electromagnetic interference (EMI) susceptibility.
For lowest offset voltage and precision performance, optimize circuit layout and mechanical conditions. Avoid
temperature gradients that create thermoelectric (Seebeck) effects in the thermocouple junctions formed from
connecting dissimilar conductors. Cancel these thermally-generated potentials by making sure that the potentials
are equal on both input terminals. Other layout and design considerations include:
•
•
•
Use low thermoelectric-coefficient conditions (avoid dissimilar metals).
Thermally isolate components from power supplies or other heat sources.
Shield operational amplifier and input circuitry from air currents, such as cooling fans.
Follow these guidelines to reduce the likelihood of junctions being at different temperatures, which can cause
thermoelectric voltage drift of 0.1 µV/°C or higher depending on materials used.
10.2 Layout Example
RIN
VIN
+
VOUT
RG
RF
Figure 10-1. Schematic Representation
GND
VS+
VOUT
Place components close
to device and to each
other to reduce parasitic
errors
Use a low-ESR,
ceramic bypass
capacitor
RF
OUT A
V+
VOUT
RG
GND
œIN A
+IN A
Vœ
OUT B
œIN B
+IN B
RF
Place components
RIN
close to device
and to each other
to reduce parasitic
errors
VIN
Run the input traces
as far away from
the supply lines
as possible
RG
Use low-ESR,
ceramic bypass
capacitor
RIN
GND
Run the input traces
as far away from
the supply lines
as possible
GND
VSœ
VIN
Ground (GND) plane on another layer
Figure 10-2. OPA387 Layout Example
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
17
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
11 Device and Documentation Support
11.1 Device Support
11.1.1 Development Support
11.1.1.1 TINA-TI Simulation Software (Free Download)
TINA-TI™ software is a simple, powerful, and easy-to-use circuit simulation program based on a SPICE engine.
TINA-TI simulation software is a free, fully-functional version of the TINA™ software, preloaded with a library of
macromodels, in addition to a range of both passive and active models. TINA-TI simulation software provides all
the conventional dc, transient, and frequency domain analysis of SPICE, as well as additional design
capabilities.
Available as a free download from the Analog eLab Design Center, TINA-TI simulation software offers extensive
post-processing capability that allows users to format results in a variety of ways. Virtual instruments offer the
ability to select input waveforms and probe circuit nodes, voltages, and waveforms, creating a dynamic quick-
start tool.
Note
These files require that either the TINA software or TINA-TI software be installed. Download the free
TINA-TI simulation software from the TINA-TI software folder.
11.2 Documentation Support
11.2.1 Related Documentation
For related documentation see the following: Texas Instruments, Circuit board layout techniques
11.3 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on
Subscribe to updates to register and receive a weekly digest of any product information that has changed. For
change details, review the revision history included in any revised document.
11.4 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
11.5 Trademarks
TINA-TI™ is a trademark of TI.
TINA™ is a trademark of DesignSoft, Inc.
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
11.6 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
11.7 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
Copyright © 2020 Texas Instruments Incorporated
18
Submit Document Feedback
Product Folder Links: OPA2387
OPA2387
www.ti.com
SBOS984A – NOVEMBER 2020 – REVISED DECEMBER 2020
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical packaging and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Copyright © 2020 Texas Instruments Incorporated
Submit Document Feedback
19
Product Folder Links: OPA2387
PACKAGE OPTION ADDENDUM
www.ti.com
29-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status Package Type Package Pins Package
Eco Plan
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
Samples
Drawing
Qty
(1)
(2)
(3)
(4/5)
(6)
OPA2387DGKR
OPA2387DGKT
ACTIVE
ACTIVE
VSSOP
VSSOP
DGK
DGK
8
8
2500 RoHS & Green
250 RoHS & Green
SN
Level-2-260C-1 YEAR
Level-2-260C-1 YEAR
-40 to 125
-40 to 125
2B2T
2B2T
SN
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
29-Dec-2020
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
24-Dec-2020
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
B0
K0
P1
W
Pin1
Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
OPA2387DGKR
OPA2387DGKT
VSSOP
VSSOP
DGK
DGK
8
8
2500
250
330.0
330.0
12.4
12.4
5.3
5.3
3.4
3.4
1.4
1.4
8.0
8.0
12.0
12.0
Q1
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
24-Dec-2020
*All dimensions are nominal
Device
Package Type Package Drawing Pins
SPQ
Length (mm) Width (mm) Height (mm)
OPA2387DGKR
OPA2387DGKT
VSSOP
VSSOP
DGK
DGK
8
8
2500
250
366.0
366.0
364.0
364.0
50.0
50.0
Pack Materials-Page 2
IMPORTANT NOTICE AND DISCLAIMER
TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE
DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES “AS IS”
AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD
PARTY INTELLECTUAL PROPERTY RIGHTS.
These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate
TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable
standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you
permission to use these resources only for development of an application that uses the TI products described in the resource. Other
reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third
party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims,
damages, costs, losses, and liabilities arising out of your use of these resources.
TI’s products are provided subject to TI’s Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on
ti.com or provided in conjunction with such TI products. TI’s provision of these resources does not expand or otherwise alter TI’s applicable
warranties or warranty disclaimers for TI products.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2020, Texas Instruments Incorporated
相关型号：
SI9130DB
5- and 3.3-V Step-Down Synchronous ConvertersWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135LG-T1
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135LG-T1-E3
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135_11
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9136_11
Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130CG-T1-E3
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130LG-T1-E3
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130_11
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137DB
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137LG
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9122E
500-kHz Half-Bridge DC/DC Controller with Integrated Secondary Synchronous Rectification DriversWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
©2020 ICPDF网 联系我们和版权申明