Datasheet
+
-
+
-
-
+
R
2
KR
2
R
1
R
1
R
2
KR
2
V
OUT
V
1
V
2
V
01
V
02
R
1
a
R
11
=
100
1k 10k 100k
600k
FREQUENCY (Hz)
0
20
40
60
80
100
120
140
CROSSTALK REJECTION (dB)
V
S
= 5V
V
S
= 2.7V
LMV771, LMV772, LMV774
SNOSA04F –MAY 2004–REVISED SEPTEMBER 2010
www.ti.com
Typical Performance Characteristics (continued)
Crosstalk Rejection
vs.
Frequency (LMV772/LMV772Q/LMV774)
Application Note
LMV771/LMV772/LMV772Q/LMV774
The LMV771/LMV772LMV772Q/LMV774 are a family of precision amplifiers with very low noise and ultra low
offset voltage. LMV771/LMV772/LMV772Q/LMV774's extended temperature range of −40°C to 125°C enables
the user to design this family of products into a variety of applications including automotive.
The LMV771 has a maximum offset voltage of 1mV over the extended temperature range. This makes the
LMV771 ideal for applications where precision is important.
The LMV772/LMV772Q/LMV774 have a maximum offset voltage of 1mV at room temperature and 1.2mV over
the extended temperature range of −40°C to 125°C. Care must be taken when the LMV772/LMV772Q/LMV774
are designed into applications with heavy loads under extreme temperature conditions. As indicated in the DC
tables, the LMV772/LMV772Q/LMV774's gain and output swing may be reduced at temperatures between 85°C
and 125°C with loads heavier than 2kΩ.
INSTRUMENTATION AMPLIFIER
Measurement of very small signals with an amplifier requires close attention to the input impedance of the
amplifier, gain of the overall signal on the inputs, and the gain on each input since we are only interested in the
difference of the two inputs and the common signal is considered noise. A classic solution is an instrumentation
amplifier. Instrumentation amplifiers have a finite, accurate, and stable gain. Also they have extremely high input
impedances and very low output impedances. Finally they have an extremely high CMRR so that the amplifier
can only respond to the differential signal. A typical instrumentation amplifier is shown in Figure 5.
Figure 5. Instrumentation Amplifier
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