Datasheet
Table Of Contents

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APPLICATIONS INFORMATION
INPUT VOLTAGE
5kW
OPA333
10mAmax
+5V
V
IN
V
OUT
I
OVERLOAD
Current-limitingresistor
requiredifinputvoltage
exceedssupplyrailsby
³ 0.5V.
OPERATING VOLTAGE
INTERNAL OFFSET CORRECTION
OPA333
OPA2333
SBOS351C – MARCH 2006 – REVISED MAY 2007
The OPA333 and OPA2333 are unity-gain stable and
free from unexpected output phase reversal. They
use a proprietary auto-calibration technique to
The OPA333 and OPA2333 input common-mode
provide low offset voltage and very low drift over time
voltage range extends 0.1V beyond the supply rails.
and temperature. For lowest offset voltage and
The OPA333 is designed to cover the full range
precision performance, circuit layout and mechanical
without the troublesome transition region found in
conditions should be optimized. Avoid temperature
some other rail-to-rail amplifiers.
gradients that create thermoelectric (Seebeck)
Normally, input bias current is about 70pA; however,
effects in the thermocouple junctions formed from
input voltages exceeding the power supplies can
connecting dissimilar conductors. These
cause excessive current to flow into or out of the
thermally-generated potentials can be made to
input pins. Momentary voltages greater than the
cancel by assuring they are equal on both input
power supply can be tolerated if the input current is
terminals. Other layout and design considerations
limited to 10mA. This limitation is easily
include:
accomplished with an input resistor, as shown in
• Use low thermoelectric-coefficient conditions
Figure 18 .
(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.
Following these guidelines will reduce the likelihood
of junctions being at different temperatures, which
can cause thermoelectric voltages of 0.1 μ V/ ° C or
higher, depending on materials used.
Figure 18. Input Current Protection
The OPA333 and OPA2333 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.
The OPA333 and OPA2333 op amps use an
Parameters that vary over supply voltage or
auto-calibration technique with a time-continuous
temperature are shown in the Typical Characteristics
350kHz op amp in the signal path. This amplifier is
section of this data sheet.
zero-corrected every 8 μ s using a proprietary
technique. Upon power-up, the amplifier requires
approximately 100 μ s to achieve specified V
OS
accuracy. This design has no aliasing or flicker
noise.
8
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