Category: Datasheet/Specs
Product Number: AD4195-4
I am evaluating AD4195-4 for ratiometric RTD measurements (Pt100). The datasheet (Rev. 0) lists a reference input current (with full buffers enabled) of ±55 nA and a drift of 1.25 nA/°C. When using 250 μA or 500 μA excitation current, the input current drift easily dominates over other drift error sources (for ≤±2ppm/°C reference resistors). For comparison, the AIN input current drift is listed as 70 pA/°C, and the reference input current drift of the older AD7124-4 is 10 pA/°C.
Are the datasheet values of AD4195-4 correct? Despite the improvements in gain error drift, INL, etc. over AD7124-4, the reference input current drift seems to make it worse for 4-wire ratiometric RTD.
