1) The AD606J Log Amp Data sheet does not state an "Absolute Maximum Ratings" input voltage (damage prevention) for the INHI (pin-16) and INLO (pin-1) volts.
Is it supply rails (0V to 5V) or is it less?
2) The two outputs (LMHI & LMLO) are described as "Open Collector" requiring 200R pull-ups.
However, these AD606 outputs can be tied to the positive rail without damaging the part (no current limit resistor). Are these a basic "open collector" output or is there more to them?