The B_OP of the TMAG5328 can also be set with the analog potentiometer that is on the EVM. To select the potentiometer option for setting B_OP, the potentiometer must be connected to the ADJ pin, which is done by the following steps:

• Do not populate resistor R7.
• Connect a jumper between the "APOT" (pin 3) and "ADJ" (pin 2) pins of header J3.

Use Equation 2 to translate the resistance between the ADJ and GND pins into the B_OP setting:

where:

• B_OP is in units of mT
• ADJ _resistance is in units of kΩ

As an example, if the resistance between ADJ and GND is 8. kΩ, then the B_OP is set to 8.5mT.

Figure 4-3 shows the schematic snippet for the potentiometer portion of the EVM. This circuit consists of a 10kΩ potentiometer (R13) in series with a 4.3kΩ fixed resistor (R2). When the potentiometer is used for setting the B_OP, the ADJ pin sees a resistance equal to the sum of resistances R2 and R13. As a result, the ADJ pin can detect a resistance somewhere between 4.3kΩ to 14.3kΩ, depending on the position of the potentiometer. The 4.3kΩ to 14.3kΩ resistance range corresponds to a B_OP of 4.3 mT to 14.3mT. A 10-kΩ potentiometer is used, therefore the potentiometer only simultaneously covers a 10mT range of B_OP settings. The resistor R2 can be modified, however, to select which B_OP options are supported. As an example, if you want to support a 2mT to 12mT range, then the user can replace R2 with a 2kΩ resistor. Similarly, if the user wants to support a 5mT to 15mT range, then replace R2 with a 5kΩ resistor.

Turning the potentiometer counterclockwise increases the resistance. Figure 4-4 and Figure 4-5 show the potentiometer positions that correspond to an ADJ resistance of 4.3kΩ and 14.3kΩ, respectively.