TMAG5328 Low-Power Hall-Effect Switch Texas Instruments TMAG5328 Low-Power Hall-Effect Switch is a high precision, low-power, resistor adjustable Hall effect switch sensor with a low operating voltage. The TMAG5328 external resistor sets the operational BOP value. Users can follow a simple formula to calculate the resistor value needed to set up the correct BOP value. The Hysteresis value is fixed, therefore, the BRP value is defined as BOP Hysteresis.