Datasheet

R
1
R
2
R
3
V
1
V
2
V
3
R
F
V
OUT
V
REF
-
+
V
OUT
= R
F
¨
¨
©
§
V
REF
- V
1
R
1
¨
¨
©
§
+
V
REF
- V
2
R
2
+
V
REF
- V
3
R
3
+
V
REF
LPV511
www.ti.com SNOSAG7C –AUGUST 2005–REVISED MARCH 2013
POWER SUPPLIES AND LAYOUT
The LPV511 operates from a single 2.7V to 12V power supply. It is recommended to bypass the power supplies
with a 0.1 μF ceramic capacitor placed close to the V
+
and V
−
pins.
Ground layout improves performance by decreasing the amount of stray capacitance and noise at the op amp's
inputs and outputs. To decrease stray capacitance, minimize PC board trace lengths and resistor leads, and
place external components close to the op amps's pins.
Typical Applications
BATTERY CURRENT SENSING
The rail-to-rail common mode input range and the very low quiescent current make the LPV511 ideal to use in
high side and low side battery current sensing applications. The high side current sensing circuit in Figure 30 is
commonly used in a battery charger to monitor the charging current in order to prevent over charging. A sense
resistor R
SENSE
is connected to the battery directly.
Figure 30. High Side Current Sensing
SUMMING AMPLIFIER
The LPV511 operational amplifier is a perfect fit in a summing amplifier circuit because of the rail-to-rail input and
output and the sub-micro Amp quiescent current. In this configuration, the amplifier outputs the sum of the three
input voltages.
The ratio of the sum and the output voltage is defined using feedback and input resistors.
(1)
Figure 31. Summing Amplifier Circuit
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