I am using ADuC7060 to measure temperature in configuration describer in AN-0970.
- Rref is 5.07 kOhm.
- Excitation current is 200 uA.
- RTD is 1 kOhm platinum resistor.
Measurement contains error about 3°C (higher than real temperature).
I recognized source of error. It is unexpected 3uA source current to VREF+ pin.
Is there something wrong with the chip?