Your red circle threw me off. Your picture doesn't have enough resolution to read the back marks or part nos. on the IC's. Ring it out a bit and maybe draw at least a partial schematic- it will start to make sense. Its most likely a linear regulator IC and an OP_AMP. if you can zoom in a bit and get some connectivity/netlist and backmarks, it would help a lot. That sensor makes a current, you feed its output to a resistor to convert to volts but better a low voltage referenced transimpedance amp. The output impedance will be quite low- <500 ohm depending on whether they put a resistor in series to make it more rugged for hobbyists. Ring it out.