OPA2378 [TI]

Low Noise, 900kHz, 50mV, Rail-to-Rail Input/Output Precision OPERATIONAL AMPLIFIER Zer┆-Drift Series; 低噪声, 900kHz的,为50mV ,轨至轨输入/输出精密运算放大器Zer┆漂移系列
OPA2378
型号: OPA2378
厂家: TEXAS INSTRUMENTS    TEXAS INSTRUMENTS
描述:

Low Noise, 900kHz, 50mV, Rail-to-Rail Input/Output Precision OPERATIONAL AMPLIFIER Zer┆-Drift Series
低噪声, 900kHz的,为50mV ,轨至轨输入/输出精密运算放大器Zer┆漂移系列

运算放大器
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OPA2378  
SBOS417JANUARY 2008  
Low Noise, 900kHz, 50µV, Rail-to-Rail Input/Output  
Precision OPERATIONAL AMPLIFIER  
Zerø-Drift Series  
1
FEATURES  
DESCRIPTION  
23  
LOW NOISE 0.1Hz to 10Hz: 0.4µVPP  
LOW OFFSET VOLTAGE: 15µV (typ)  
QUIESCENT CURRENT: 100µA (typ)  
OFFSET DRIFT: 0.1µV/°C (typ)  
The OPA378 and OPA2378 represent  
a new  
generation of micropower operational amplifiers.  
Rail-to-rail input, low input offset voltage (50µV max),  
low quiescent current (125µA max), and 900kHz  
bandwidth make this part very attractive for  
low-power precision applications. In addition, this part  
has excellent PSRR, making it an outstanding choice  
for applications that run directly from batteries without  
regulation.  
SINGLE-SUPPLY OPERATION  
SUPPLY VOLTAGE: 1.8V to 5.5V  
microSIZE PACKAGES: SC70 and SOT23  
APPLICATIONS  
The OPA378 (single version) is available in a  
microSIZE SC70-5 and SOT23-5. The OPA2378  
(dual version) is offered in s SOT23-8 package. All  
versions are specified for operation from –40°C to  
+125°C.  
BATTERY-POWERED INSTRUMENTS  
TEMPERATURE MEASUREMENT  
MEDICAL INSTRUMENTATION  
HANDHELD TEST EQUIPMENT  
INPUT CURRENT AND VOLTAGE NOISE  
0.1Hz TO 10Hz NOISE  
SPECTRAL DENSITY vs FREQUENCY  
100  
Voltage Noise  
10  
0
1
10  
100  
1k  
10k 30k  
Time (1s/div)  
Frequency (Hz)  
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of  
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.  
2
3
I2C is a trademark of NXP Semiconductors.  
All other trademarks are the property of their respective owners.  
PRODUCT PREVIEW information concerns products in the  
formative or design phase of development. Characteristic data and  
other specifications are design goals. Texas Instruments reserves  
the right to change or discontinue these products without notice.  
Copyright © 2008, Texas Instruments Incorporated  
OPA378  
OPA2378  
www.ti.com  
SBOS417JANUARY 2008  
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.  
ORDERING INFORMATION(1)  
PRODUCT  
OPA378  
OPA378(2)  
OPA2378(2)  
PACKAGE-LEAD  
SOT23-5  
PACKAGE DESIGNATOR  
PACKAGE MARKING  
DBV  
DCK  
DCN  
OAZI  
BTS  
SC70-5  
SOT23-8  
OCAI  
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI  
web site at www.ti.com.  
(2) Available 1Q08.  
ABSOLUTE MAXIMUM RATINGS(1)  
Over operating free-air temperature range (unless otherwise noted).  
OPA378, OPA2378  
UNIT  
V
Supply Voltage  
+7  
–0.3 VIN (V+) + 0.3  
±10  
Voltage(2)  
Current(2)  
V
Signal Input Terminals  
mA  
Output Short-Circuit(3)  
Operating Temperature  
Storage Temperature  
Junction Temperature  
Continuous  
–55 to +150  
–65 to +150  
+150  
°C  
°C  
°C  
V
Human Body Model (HBM)  
Charged Device Model (CDM)  
Machine Model (MM)  
4000  
ESD Ratings  
1000  
V
200  
V
(1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may  
degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond  
those specified is not supported.  
(2) Input terminals are diode-clamped to the power-supply rails. Input signals that can swing more than 0.3V beyond the supply rails should  
be current limited to 10mA or less.  
(3) Short-circuit to ground, one amplifier per package.  
PIN CONFIGURATIONS  
OPA378  
SOT23-5  
Top View  
OPA2378  
SC70-5  
Top View  
OPA378  
SC70-5  
Top View  
Out A  
-In A  
+In A  
V-  
1
2
3
4
8
7
6
5
V+  
+IN  
V-  
1
2
3
5
4
V+  
Out  
V-  
1
2
3
5
4
V+  
A
Out B  
-In B  
+In B  
B
-IN  
OUT  
+In  
-In  
2
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OPA378  
OPA2378  
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SBOS417JANUARY 2008  
ELECTRICAL CHARACTERISTICS: VS = +1.8V to +5.5V  
Boldface limits apply over the specified temperature range, TA = –40°C to +125°C.  
At TA = +25°C, RL = 10kconnected to VS/2, VCM = VS/2, and VOUT = VS/2, unless otherwise noted.  
OPA378, OPA2378  
PARAMETER  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
OFFSET VOLTAGE  
Input Offset Voltage  
vs Temperature  
VOS  
dVOS/dT  
PSRR  
15  
0.1  
2
50  
0.25  
5
µV  
µV/°C  
µV/V  
µV/V  
µV/V  
vs Power Supply  
VCM = 0V, VS = +1.8V to +5.5V  
over Temperature  
VCM = 0V, VS = +1.8V to +5.5V  
8
Channel Separation, dc  
INPUT BIAS CURRENT  
Input Bias Current  
0.1  
IB  
±150  
±500  
pA  
pA  
Input Offset Current  
IOS  
±1000  
NOISE  
Input Voltage Noise, f = 0.1Hz to 10Hz  
Input Voltage Noise Density, f = 1kHz  
Input Current Noise, f = 10Hz  
INPUT VOLTAGE RANGE  
Common-Mode Voltage Range  
Common-Mode Rejection Ratio  
en  
en  
in  
0.4  
20  
µVPP  
nV/Hz  
fA/Hz  
200  
VCM  
(V–) – 0.1  
100  
(V+) + 0.1  
V
CMRR (V–) – 0.1V < VCM < (V+) + 0.1V, VS = 5.5V  
(V–) – 0.1V < VCM < (V+) + 0.1V, VS = 1.8V  
110  
103  
dB  
dB  
94  
OPEN-LOOP GAIN  
Open-Loop Voltage Gain  
AOL  
50mV < VO < (V+) – 50mV, RL = 100kΩ  
100mV < VO < (V+) – 100mV, RL = 10kΩ  
CL = 100pF  
110  
110  
134  
130  
dB  
dB  
FREQUENCY RESPONSE  
Gain-Bandwidth Product  
Slew Rate  
GBW  
SR  
tD  
900  
kHz  
V/µs  
µs  
G = +1  
0.4  
Settling Time 0.1%  
VS = 5.5V, 2V Step, G = +1  
VS = 5.5V, 2V Step, G = +1  
VIN • Gain > VS  
5
Settling Time 0.01%  
Overload Recovery Time  
THD + Noise  
tD  
7
4
µs  
µs  
THD + N  
VS = 5.5V, VO = 3VPP, G = +1, f = 1kHz  
0.0012  
%
OUTPUT  
Voltage Output Swing from Rail  
over Temperature  
RL = 10kΩ  
RL = 10k  
RL = 100kΩ  
RL = 100kΩ  
6
8
10  
1
mV  
mV  
mV  
mV  
mA  
Voltage Output Swing from Rail  
over Temperature  
0.7  
2
Short-Circuit Current  
Capacitive Load Drive  
Open-Loop Output Resistance  
POWER SUPPLY  
ISC  
CLOAD  
RO  
±10  
See Typical Characteristics  
See Typical Characteristics  
Specified Voltage Range  
Quiescent Current (per Amplifier)  
over Temperature  
VS  
IQ  
1.8  
5.5  
V
IO = 0V, VS = +5.5V  
100  
125  
µA  
µA  
135  
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OPA378  
OPA2378  
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SBOS417JANUARY 2008  
ELECTRICAL CHARACTERISTICS: VS = +1.8V to +5.5V (continued)  
Boldface limits apply over the specified temperature range, TA = –40°C to +125°C.  
At TA = +25°C, RL = 10kconnected to VS/2, VCM = VS/2, and VOUT = VS/2, unless otherwise noted.  
OPA378, OPA2378  
PARAMETER  
TEMPERATURE RANGE  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
Specified Range  
Operating Range  
Storage Range  
Thermal Resistance  
SOT23-5  
–40  
–55  
–65  
+125  
+150  
+150  
°C  
°C  
°C  
θJA  
°C/W  
°C/W  
°C/W  
°C/W  
200  
250  
100  
SC70-5  
SOT23-8  
4
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OPA378  
OPA2378  
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SBOS417JANUARY 2008  
TYPICAL CHARACTERISTICS  
At TA = +25°C, RL = 10k, VS = +5.5V and VOUT = VS/2, unless otherwise noted.  
MAXIMUM OUTPUT VOLTAGE  
vs FREQUENCY  
INPUT CURRENT AND VOLTAGE NOISE  
SPECTRAL DENSITY vs FREQUENCY  
6
1k  
100  
10  
VS = 5.5V  
5
4
3
2
1
0
Current Noise  
Voltage Noise  
VS = 1.8V  
1
10  
100  
1k  
10k 30k  
1k  
10k  
100k  
1M  
10M  
Frequency (Hz)  
Frequency (Hz)  
Figure 1.  
Figure 2.  
TOTAL HARMONIC DISTORTION + NOISE  
vs FREQUENCY  
OPEN-LOOP GAIN AND PHASE  
vs FREQUENCY  
180  
135  
90  
0.0050  
0.0045  
0.0040  
0.0035  
0.0030  
0.0025  
0.0020  
0.0015  
0.0010  
0.0005  
0
0
-45  
-90  
-135  
-180  
-225  
Phase  
45  
Gain  
0
-45  
10  
100  
1k  
10k  
0.01 0.1  
1
10  
100  
1k  
10k 100k 1M 10M  
Frequency (Hz)  
Frequency (Hz)  
Figure 3.  
Figure 4.  
COMMON-MODE REJECTION RATIO  
vs FREQUENCY  
POWER-SUPPLY REJECTION RATIO  
vs FREQUENCY  
120  
100  
80  
60  
40  
20  
0
120  
100  
80  
V+  
V-  
60  
40  
20  
0
1
10  
100  
1k  
10k  
100k  
1M  
10  
100  
1k  
10k  
100k  
1M  
Frequency (Hz)  
Frequency (Hz)  
Figure 5.  
Figure 6.  
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OPA378  
OPA2378  
www.ti.com  
SBOS417JANUARY 2008  
TYPICAL CHARACTERISTICS (continued)  
At TA = +25°C, RL = 10k, VS = +5.5V and VOUT = VS/2, unless otherwise noted.  
QUIESCENT CURRENT  
vs SUPPLY VOLTAGE  
VOLTAGE OFFSET vs TEMPERATURE  
40  
35  
30  
25  
20  
15  
10  
5
102  
101  
100  
99  
98  
97  
96  
95  
94  
0
93  
-50  
-25  
0
25  
50  
75  
100  
125  
150  
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0  
Temperature (°C)  
VS (V)  
Figure 7.  
Figure 8.  
QUIESCENT CURRENT  
vs TEMPERATURE  
INPUT BIAS CURRENT  
vs INPUT COMMON-MODE VOLTAGE  
110  
108  
106  
104  
102  
100  
98  
250  
200  
150  
100  
50  
-IN  
0
-50  
-100  
-150  
-200  
-250  
+IN  
96  
94  
92  
90  
-50  
-25  
0
25  
50  
75  
100  
125  
150  
0
1
2
3
4
5
6
Temperature (°C)  
Input Common-Mode Voltage (V)  
Figure 9.  
Figure 10.  
INPUT BIAS CURRENT  
vs TEMPERATURE  
OUTPUT VOLTAGE SWING  
vs OUTPUT CURRENT  
3
2
1500  
1000  
500  
VS = +2.75  
-40°C  
+25°C  
+125°C  
1
-IN  
+125°C  
+25°C  
-40°C  
0
0
VS = ±0.9  
+IN  
-1  
-2  
-3  
-500  
-1000  
-1500  
-40°C  
+25°C  
+125°C  
VS = -2.75  
-50  
-25  
0
25  
50  
75  
100  
125  
150  
0
2
4
6
8
10  
12  
14  
16  
18  
20  
Temperature (°C)  
Output Current (mA)  
Figure 11.  
Figure 12.  
6
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Product Folder Link(s): OPA378 OPA2378  
OPA378  
OPA2378  
www.ti.com  
SBOS417JANUARY 2008  
TYPICAL CHARACTERISTICS (continued)  
At TA = +25°C, RL = 10k, VS = +5.5V and VOUT = VS/2, unless otherwise noted.  
COMMON-MODE REJECTION RATIO AND PSRR  
vs TEMPERATURE  
OPEN-LOOP GAIN  
vs TEMPERATURE  
120  
115  
110  
105  
100  
95  
140  
135  
130  
125  
120  
PSRR  
RL = 100kW  
VS = 5.5V  
VS = 1.8V  
CMRR  
RL = 10kW  
RL = 5kW  
90  
85  
80  
-50  
-25  
0
25  
50  
75  
100  
125  
150  
-50  
-25  
0
25  
50  
75  
100  
125  
150  
Temperature (°C)  
Temperature (°C)  
Figure 13.  
Figure 14.  
SMALL-SIGNAL OVERSHOOT  
vs LOAD CAPACITANCE  
SMALL-SCALE STEP RESPONSE  
80  
70  
60  
50  
40  
30  
20  
10  
0
G = +1  
RL = 10kW  
Gain = -1V/V  
RFB = 100kW  
Gain = +1V/V  
Gain = -1V/V  
RFB = 5kW  
Time (4ms/div)  
1
10  
100  
1k 10k  
Load Capacitor (pF)  
Figure 15.  
Figure 16.  
POSITIVE OVER-VOLTAGE RECOVERY  
NEGATIVE OVER VOLTAGE RECOVERY  
Output  
10kW  
+2.5V  
10kW  
1kW  
Output  
+2.5V  
OPA378  
0
1kW  
OPA378  
2.5V  
2.5V  
Input  
0
Input  
Time (10ms/div)  
Time (4ms/div)  
Figure 17.  
Figure 18.  
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OPA378  
OPA2378  
www.ti.com  
SBOS417JANUARY 2008  
TYPICAL CHARACTERISTICS (continued)  
At TA = +25°C, RL = 10k, VS = +5.5V and VOUT = VS/2, unless otherwise noted.  
OFFSET VOLTAGE  
PRODUCTION DISTRIBUTION  
0.1Hz TO 10Hz NOISE  
TBD  
Time (1s/div)  
Figure 19.  
Figure 20.  
OFFSET VOLTAGE DRIFT  
PRODUCTION DISTRIBUTION  
1000  
OUTPUT IMPEDANCE  
vs FREQUENCY  
100  
10  
1
400mA  
2mA  
0.1  
0.01  
1
10  
100  
1k  
10k  
100k  
1M  
10M  
Frequency (Hz)  
Offset Voltage Drift (mV/°C)  
Figure 21.  
Figure 22.  
8
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OPA2378  
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SBOS417JANUARY 2008  
APPLICATIONS INFORMATION  
The OPA378 and OPA2378 are unity-gain stable and  
free from unexpected output phase reversal. These  
devices use a proprietary auto-calibration technique  
to provide low offset voltage and very low drift over  
time and temperature. For lowest offset voltage and  
precision performance, circuit layout and mechanical  
conditions should be optimized. Avoid temperature  
gradients that create thermoelectric (Seebeck) effects  
in the thermocouple junctions formed from connecting  
dissimilar conductors. These thermally-generated  
potentials can be made to cancel by assuring they  
are equal on both input terminals. Other layout and  
design considerations include:  
Current-limiting resistor  
required if input voltage  
exceeds supply rails by  
³ 0.5V.  
+5V  
IOVERLOAD  
10mA max  
VOUT  
OPA378  
VIN  
5kW  
Figure 23. Input Current Protection  
INTERNAL OFFSET CORRECTION  
Use low thermoelectric-coefficient conditions  
(avoid dissimilar metals).  
Thermally isolate components from power  
supplies or other heat sources.  
Shield op amp and input circuitry from air  
currents, such as cooling fans.  
The OPA378 and OPA2378 op amps use an  
auto-calibration technique with a time-continuous  
350kHz op amp in the signal path. This amplifier is  
zero-corrected every 3µs using  
a
proprietary  
technique. Upon power-up, the amplifier requires  
approximately 100µs to achieve specified VOS  
accuracy. This architecture has no aliasing or flicker  
noise.  
Following these guidelines reduces the likelihood of  
junctions being at different temperatures, which can  
cause thermoelectric voltages of 0.1µV/°C or higher,  
depending on materials used.  
GENERAL LAYOUT GUIDELINES  
OPERATING VOLTAGE  
Attention to good layout practices is always  
recommended. 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 0.1µF  
capacitor closely across the supply pins. These  
guidelines should be applied throughout the analog  
circuit to improve performance and provide  
benefits such as reducing the electromagnetic  
interference (EMI) susceptibility.  
The OPA378 and OPA2378 op amps operate over a  
power-supply range of +1.8V to +5.5V (±0.9V to  
±2.75V). Supply voltages higher than +7V (absolute  
maximum) can permanently damage the device.  
Parameters that vary over supply voltage or  
temperature are shown in the Typical Characteristics  
section of this data sheet.  
INPUT VOLTAGE  
Operational amplifiers vary in susceptibility to radio  
frequency interference (RFI). RFI can generally be  
identified as a variation in offset voltage or dc signal  
levels with changes in the interfering RF signal. The  
OPA378 has been specifically designed to minimize  
susceptibility to RFI and demonstrates remarkably  
low sensitivity compared to previous generation  
devices. Despite this design, strong RF fields may  
cause varying offset levels. If the amplifier cannot be  
located away from sources of radiation, shielding may  
be needed. Twisting wire input leads makes them  
more resistant to RF fields.  
The OPA378 and OPA2378 input common-mode  
voltage range extends 0.1V beyond the supply rails.  
The OPA378 is designed to cover the full  
common-mode range without the troublesome  
transition region found in some other rail-to-rail  
amplifiers.  
Normally, input bias current is about 150pA; however,  
input voltages exceeding the power supplies can  
cause excessive current to flow into or out of the  
input pins. Momentary voltages greater than the  
power supply can be tolerated if the input current is  
limited to 10mA. This limitation is easily accomplished  
with an input resistor, as shown in Figure 23.  
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4.096V  
REF3140  
+5V  
0.1mF  
+
R8  
150kW  
R1  
6.04kW  
R5  
+5V  
31.6kW  
10mF  
D1  
0.1mF  
R2  
R7  
2.94kW  
549W  
-
-
+
+
VO  
OPA378  
R6  
K-Type  
200W  
Thermocouple  
R4  
6.04kW  
R3  
Zero Adj.  
40.7mV/°C  
60.4W  
Figure 24. Temperature Measurement  
Figure 25 shows the basic configuration for a bridge  
amplifier.  
VEX  
R1  
A
low-side current shunt monitor is shown in  
+5V  
Figure 26. RN are operational resistors used to isolate  
the ADS1100 from the noise of the digital I2C™ bus.  
Because the ADS1100 is a 16-bit converter, a precise  
reference is essential for maximum accuracy. If  
absolute accuracy is not required, and the 5V power  
supply is sufficiently stable, the REF3130 may be  
omitted.  
R
R
R
R
VOUT  
OPA378  
R1  
VREF  
Figure 25. Single Op Amp Bridge Amplifier  
3V  
REF3130  
+5V  
Load  
R1  
4.99kW  
R2  
49.9kW  
R6  
71.5kW  
RN  
56W  
V
RSHUNT  
1W  
ILOAD  
OPA378  
I2C  
RN  
56W  
R3  
4.99kW  
R4  
48.7kW  
ADS1100  
R7  
1.18kW  
(PGA Gain = 4)  
FS = 3.0V  
Stray Ground-Loop Resistance  
NOTE: 1% resistors provide adequate common-mode rejection at small ground-loop errors.  
Figure 26. Low-Side Current Monitor  
10  
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SBOS417JANUARY 2008  
Figure 27 shows a high side current monitor. The  
load current develops a drop across RSHUNT, and the  
low (or load side, most negative side) of RSHUNT is  
connected to the noninverting input of the op amp.  
The op amp feedback forces a replica of this voltage  
on its inverting input, yielding a drop across RG that is  
identical to the drop across RSHUNT. RG can be sized  
to provide whatever current is most convenient to the  
designer based on this voltage drop. The MOSFET  
conveys this current out of its drain to ground, where  
a resistor RL converts the current that flows through  
RG and the MOSFET back into a voltage. In this way  
RL/RG sets the voltage gain of this circuit. The op  
amp is powered by the zener diode, which forms a  
small power supply window of voltage. For the  
OPA378, ±VS but must be between 1.8V and  
5.5V.Two possible methods are shown to bias the  
zener, the customary resistor bias and a current  
mirror. To operate over at the lowest possible voltage  
for the shunt supply, current mirror biasing could also  
be used. In either case, note that the voltage at the  
output terminal of this circuit is restricted by whatever  
voltage is available at the shunt. Resistor R1 and the  
diode on the noninverting input provide protection in  
situations where the load might be shorted out. These  
components clamp the noninverting input to within a  
diode drop of the negative rail of the op amp under  
short-circuit conditions.  
RG  
zener(1)  
V+  
CBYPASS  
RSHUNT  
(2)  
R1  
10kW  
MOSFET rated to  
stand-off supply voltage  
such as BSS84 for  
OPA378  
up to 50V.  
+5V  
V+  
Two zener  
biasing methods  
are shown.(3)  
Output  
Load  
RBIAS  
RL  
(1) zener rated for op amp supply capability (that is, 5.1V for OPA378).  
(2) Current-limiting resistor.  
(3) Choose zener biasing resistor or dual NMOSFETs (FDG6301N, NTJD4001N, or Si1034)  
NOTES:  
Figure 27. High-Side Current Monitor  
100kW  
V1  
-In  
1MW  
60kW  
INA152  
OPA378  
2
5
6
3V  
R2  
NTC  
Thermistor  
1MW  
OPA378  
VO  
R1  
R2  
3
1
Figure 28. Thermistor Measurement  
OPA378  
V2  
+In  
VO = (1 + 2R2/R1) (V2 - V1)  
Figure 29. Precision Instrumentation Amplifier  
Copyright © 2008, Texas Instruments Incorporated  
Submit Documentation Feedback  
11  
Product Folder Link(s): OPA378 OPA2378  
 
OPA378  
OPA2378  
www.ti.com  
SBOS417JANUARY 2008  
+VS  
fLPF = 150Hz  
C4  
R1  
100kW  
1/2  
1.06nF  
OPA2378  
RA  
R14  
GTOT = 1kV/V  
1MW  
R7  
+VS  
100kW  
+VS  
GINA = 5  
R12  
R6  
+VS  
3
2
7
5kW  
100kW  
R2  
100kW  
LL  
1/2  
6
1
INA321(1)  
OPA2378  
VOUT  
OPA378  
4
5
C3  
GOPA = 200  
1mF  
R13  
R8  
318kW  
100kW  
+VS  
+VS  
dc  
ac  
R3  
100kW  
LA  
1/2  
1/2  
OPA2378  
Wilson  
OPA2378  
VCENTRAL  
C1  
(RA + LA + LL)/3  
47pF  
fHPF = 0.5Hz  
(provides ac signal coupling)  
1/2 VS  
R5  
390kW  
+VS  
VS = +2.7V to +5.5V  
BW = 0.5Hz to 150Hz  
R9  
+VS  
20kW  
R4  
100kW  
RL  
1/2  
OPA2378  
1/2  
OPA2378  
Inverted  
VCM  
+VS  
R10  
NOTE: (1) Other instrumentation amplifiers can be used,  
such as the INA326, which has lower noise,  
but higher quiescent current.  
1MW  
1/2 VS  
R11  
C2  
1MW  
0.64mF  
fO = 0.5Hz  
Figure 30. Single-Supply, Very Low Power, ECG Circuit  
12  
Submit Documentation Feedback  
Copyright © 2008, Texas Instruments Incorporated  
Product Folder Link(s): OPA378 OPA2378  
PACKAGE OPTION ADDENDUM  
www.ti.com  
3-Jan-2008  
PACKAGING INFORMATION  
Orderable Device  
Status (1)  
Package Package  
Pins Package Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)  
Qty  
Type  
Drawing  
OPA378AIDBVR  
OPA378AIDBVT  
PREVIEW  
PREVIEW  
SOT-23  
SOT-23  
DBV  
5
5
3000  
250  
TBD  
TBD  
Call TI  
Call TI  
Call TI  
Call TI  
DBV  
(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)  
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check  
http://www.ti.com/productcontent for the latest availability information and additional product content details.  
TBD: The Pb-Free/Green conversion plan has not been defined.  
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements  
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered  
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.  
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and  
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS  
compatible) as defined above.  
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame  
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)  
(3)  
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder  
temperature.  
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  

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