We are running tests on a circuit operating up towards 200 to 210 C and using an OPA2333-HT to source a constant 1 mA current through a platinum RTD. We begin to see the RTD measurement go off-course above 155 Celsius, which our troubleshooting indicates is a limitation of the Op Amp to source the 1 mA current.
The datasheet shows in Figure 7 the correlation between the source voltage, output voltage swing, output current and temperature. We notice that as temperature increases, the output current reduces significantly (most notably when operating on 5.5V total rails), but it is shown only up to +125 C.
If we operate at the 210 C max rated temperature for this Op Amp, what is the guaranteed maximum output current? Does it differ significantly if we operate with Vs = 3.3V (single supply) instead of the 5.5V as shown?
