Many modern day electronic components utilize sensors to measure physical quantities and to convert the measured physical quantities into signals that are provided to an electronic instrument (e.g., integrated chip processor). In hand held portable devices (e.g., cell phones) sensors are ideally operated at a low power to enable long battery life. One way to conserve power is to use sensor signals having a small amplitude. However, to accurately convey information using signals with a small amplitude, offset values within the signals must be kept low.
Chopping switches are often used for linear amplifiers or analog-to-digital converts (ADCs) to achieve low offset values. Chopping switches can be operated to reduce the offset error by switching the outputs of the Hall plate at a chopping frequency that alternatively adds an offset value (e.g., 10 mV) and subtracts the offset value (e.g., −10 mV) from the induced Hall signal. Such chopping generates a modulated chopping signal at a chopping frequency, due to the swapping, that has an offset with a mean value of zero
USPTO Backgrounds
USPTO Backgrounds