Data Sheet
Application Information
General Description
The LMV321 is a single supply, general purpose, voltage-
feedback amplifier fabricated on a CMOS process. The
LMV321 offers 1MHz gain bandwidth product, >1V/ s slew
rate, and only 130 A supply current. It features a rail-to-rail
output stage and is unity gain stable.
The common mode input range extends to 200mV below
ground and to 800mV below Vs. Exceeding these values
will not cause phase reversal. However, if the input voltage
exceeds the rails by more than 0.5V, the input ESD devices
will begin to conduct. The output will stay at the rail during
this overdrive condition.
The output stage is short circuit protected and offers “soft”
saturation protection that improves recovery time.Figures
1, 2, and 3 illustrate typical circuit configurations for non-
inverting, inverting, and unity gain topologies for dual supply
applications. They show the recommended bypass capacitor
values and overall closed loop gain equations. Figure 4
shows the typical non-inverting gain circuit for single supply
applications
+V
s
6.8µF
R
g
+V
s
6.8µF
Input
+
-
0.1µF
Output
R
L
0.1µF
LMV321
General Purpose, Rail-to-Rail Output Amplifier
6.8µF
-V
s
G=1
Figure 3. Unity Gain Circuit
+V
s
6.8µF
Input
+
-
0.1µF
Output
R
L
R
f
Input
+
-
0.1µF
Output
R
L
0.1µF
R
f
Figure 4. Single Supply Non-Inverting Gain Circuit
Power Dissipation
Power dissipation should not be a factor when operating
under the stated 2k load condition. However, applications
with low impedance, DC coupled loads should be analyzed
to ensure that maximum allowed junction temperature
is not exceeded. Guidelines listed below can be used to
verify that the particular application will not cause the
device to operate beyond it’s intended operating range.
Maximum power levels are set by the absolute maximum
junction rating of 150°C. To calculate the junction
temperature, the package thermal resistance value
Theta
JA
(
JA
) is used along with the total die power
dissipation.
T
Junction
= T
Ambient
+ (
JA
Rev 1
R
g
-V
s
6.8µF
G = 1 + (R
f
/R
g
)
Figure 1. Typical Non-Inverting Gain Circuit
+V
s
6.8µF
R
1
Input
R
g
+
-
0.1µF
Output
R
L
0.1µF
R
f
G = - (R
f
/R
g
)
For optimum input offset
voltage set R
1
= R
f
|| R
g
× P
D
)
6.8µF
-V
s
Where T
Ambient
is the temperature of the working environment.
In order to determine P
D
, the power dissipated in the load
needs to be subtracted from the total power delivered by
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Figure 2. Typical Inverting Gain Circuit
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12
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