Circuits and techniques for performing self-test diagnostics in a magnetic field sensor

Systems and methods are provided herein for performing a self-test of a magnetic field sensor using internal diagnostic components for fault detection. The magnetic field sensor includes a magnetic sensing element coupled to a sensor biasing current source and a switching network coupled to the magnetic sensing element. The switching network includes one or more diagnostics switches and one or more signal switches, and the one or more diagnostic switches are coupled to a diagnostic input current source. The switching network is configured to generate a time-multiplexed signal having a magnetic signal responsive to an external magnetic field in a magnetic signal time period and a diagnostic signal in a diagnostic signal time period. The diagnostic signal may be operable to produce an intermediate signal to have a predetermined sequence between a first state and a second state.