Signal processor for use in electronic compass

Abstract

In a signal processor for use in an electronic compass for controlling an offset voltage generated in an analog signal process and automatically controlling an amplification gain, an analog signal processoramplifies signals Sx and Sy, and controls an offset voltage and amplitude A generated during an amplification process. An analog/digital (AD) converterconverts analog signals Vadcx and Vadcy from the analog signal processorinto a digital signal. A digital signal processormeasures a maximum value Vand a minimum value Vassociated with the digital signal from the AD converterand outputs, to the analog signal processoran offset control signal Soc and a gain control signal Sgc based on the maximum value Vand minimum value V. The signal processor can maintain levels of signals, to be inputted into the AD converter, to be within a reference voltage range.