Integrated circuit for use with an external hall sensor, and hall sensor module

Abstract

An integrated circuit for use with an external Hall sensor that permits to at least substantially cancel out the temperature drifts of the Hall sensor, as caused by the temperature drift of the current supplied to the Hall sensor, and the gain of the Sigma-Delta modulator. Specifically, the circuit provides an integrated circuit for use with an external Hall sensor, that has an analog input for application of a Hall voltage from the Hall sensor, a digital data output and a current output for connection to a current input of the Hall sensor. The integrated circuit comprises a Sigma-Delta modulator with an input connected to the analog input and an output connected to the digital data output. An internal reference voltage source is also included in the integrated circuit, and an internal current source is connected to the current output for the Hall sensor. The internal reference voltage source is used as a reference in the current source that determines the amount of current supplied to the Hall sensor, and is also used in the Sigma-Delta modulator as a reference that determines the input voltage range. Since the same reference voltage source is used by the current source for the Hall sensor and by the Sigma-Delta modulator, the temperature drifts of the Hall voltage and the gain of the Sigma-Delta modulator cancel each other. Other benefits are low noise and an excellent common mode rejection.