OPA333_15 Datasheet, PDF (10/33 Pages) Texas Instruments – 1.8-V, microPower, CMOS Operational Amplifiers, Zero-Drift Series

OPA333
OPA2333
SBOS351D – MARCH 2006 – REVISED NOVEMBER 2013
DETAILED DESCRIPTION
www.ti.com
The OPA333 and OPA2333 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, optimize circuit layout and mechanical
conditions. Avoid temperature gradients that create thermoelectric (Seebeck) effects in the thermocouple
junctions formed from connecting dissimilar conductors. Cancel these thermally-generated potentials by assuring
they are equal on both input terminals. Other layout and design considerations include:
• 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.
Following these guidelines reduces the likelihood of junctions being at different temperatures, which can cause
thermoelectric voltages of 0.1 μV/°C or higher, depending on materials used.
OPERATING VOLTAGE
The OPA333 and OPA2333 op amps operate over a power-supply range of +1.8 V to +5.5 V (±0.9 V to ±2.75 V).
Parameters that vary over supply voltage or temperature are shown in the Typical Characteristics section.
CAUTION
Supply voltages higher than +7 V (absolute maximum) can permanently damage the
device.
INPUT VOLTAGE
The OPA333 and OPA2333 input common-mode voltage range extends 0.1 V beyond the supply rails. The
OPA333 is designed to cover the full range without the troublesome transition region found in some other rail-to-
rail amplifiers.
Typically, input bias current is approximately 70 pA; 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 10 mA. This limitation is easily accomplished with an input
resistor, as shown in Figure 18.
Current-limiting resistor
required if input voltage
exceeds supply rails by
³ 0.5 V.
I_OVERLOAD
10 mA max
V_IN
5 kW
+5 V
OPA333
V_OUT
Figure 18. Input Current Protection
10
Submit Documentation Feedback
Copyright © 2006–2013, Texas Instruments Incorporated
Product Folder Links: OPA333 OPA2333