OPA2333-Q1 Datasheet, PDF (8/16 Pages) Texas Instruments – 1.8-V MICROPOWER CMOS OPERATIONAL AMPLIFIER ZERO-DRIFT SERIES

OPA2333-Q1
SBOS463A – DECEMBER 2008 – REVISED JUNE 2010
www.ti.com
V+ = +5 V
1/2
OPA2333
V_OUT
V_IN
R_P = 20 kW
Op Amp
V– = Ground
-5 V
Additional
Negative Supply
Figure 2. V_OUT Range to Ground
The OPA2333A has an output stage that allows the output voltage to be pulled to its negative supply rail, or
slightly below, using the technique previously described. This technique only works with some types of output
stages. The OPA2333A has been characterized to perform with this technique; however, the recommended
resistor value is approximately 20 kΩ. Note that this configuration increases the current consumption by several
hundreds of microamps. Accuracy is excellent down to 0 V and as low as –2 mV. Limiting and nonlinearity
occurs below –2 mV, but excellent accuracy returns as the output is again driven above –2 mV. Lowering the
resistance of the pulldown resistor allows the op amp to swing even further below the negative rail. Resistances
as low as 10 kΩ can be used to achieve excellent accuracy down to –10 mV.
General Layout Guidelines
Attention to good layout practices is always recommended. Keep traces short and, when possible, use a printed
circuit board (PCB) ground plane with surface-mount components placed as close to the device pins as possible.
Place a 0.1-mF capacitor closely across the supply pins. These guidelines should be applied throughout the
analog circuit to improve performance and provide benefits, such as reducing the electromagnetic interference
(EMI) susceptibility.
Operational amplifiers vary in their susceptibility to radio frequency interference (RFI). RFI can generally be
identified as a variation in offset voltage or dc signal levels with changes in the interfering RF signal. The
OPA2333A has been specifically designed to minimize susceptibility to RFI and demonstrates remarkably low
sensitivity compared to previous-generation devices. Strong RF fields may still cause varying offset levels.
+5V
+
0.1µF
REF3140
D1
4.096V
R₁
6.04kW
R₅
31.6kW
R₉
150kW
+5V
0.1µF
R₂
R₂
--
2.94kW
549W
++
K-Type
R₆
200W
1/2
OPA2333
V_O
Thermocouple
R₄
R₃
Zero Adj.
40.7µV/°C
6.04kW 60.4W
Figure 3. Temperature Measurement
Figure 4 shows the basic configuration for a bridge amplifier.
8
Submit Documentation Feedback
Copyright © 2008–2010, Texas Instruments Incorporated
Product Folder Link(s): OPA2333-Q1