Abstract: Disclosed herein is a photodiode cell, including: a first-type substrate; a second-type epitaxial layer disposed on the first-type substrate; heavily-doped second-type layers, each having a small depth, formed on the second-type epitaxial layer; and heavily-doped first-type layers, each having a narrow and shallow section, disposed on the second-type epitaxial layer and formed between the heavily-doped second-type layers, wherein the first-type and second-type have opposite doped states.

Abstract: Disclosed herein is a photodiode cell, including: a first-type substrate; a second-type epitaxial layer disposed on the first-type substrate; heavily-doped second-type layers, each having a small depth, formed on the second-type epitaxial layer; and heavily-doped first-type layers, each having a narrow and shallow section, disposed on the second-type epitaxial layer and formed between the heavily-doped second-type layers, wherein the first-type and second-type have opposite doped states.

Abstract: Provided are a finger type photodiode and a method of manufacturing the same, which can reduce noise by forming a shallow doping layer. The finger type photodiode includes a bottom substrate supporting layers to be formed thereon, an epitaxial layer formed on the bottom substrate, a finger doping layer formed in a finger shape on a top surface of the epitaxial layer, and a shallow doping layer formed with a shallow depth on an externally exposed top surface of the epitaxial layer and a top surface of the finger doping layer. Since the dangling bond generated on the epitaxial layer and the finger doping layer is reduced, noise can be reduced, thereby improving the light efficiency and reliability of the photodiode.

Abstract: Provided is an oscillator using a Schmitt trigger circuit, the oscillator including a constant current generating section that generates a current with a constant magnitude; a current mirroring section that is connected to the constant current generating section and mirrors the current generated by the constant current generating section; a control section that is connected to the current mirroring section and supplies or blocks the current applied through the current mirroring section; a capacitor of which one end is connected to the control section and the other end is grounded, the capacitor being charged with a current supplied by the control section; a Schmitt trigger circuit that receives the voltage charged in the capacitor so as to output a high- or low-level voltage; and a voltage delay section that is connected to the Schmitt trigger circuit and delays the voltage output by the Schmitt trigger circuit to output.

Abstract: A method of finding a dip angle in a tilt-compensated electronic compass includes the steps of a) setting a predetermined azimuth angle indicative of a horizontal status of a geomagnetic sensor to a reference azimuth angle; b) if the compass is slightly tilted, stepwise-increasing a dip angle within a predetermined dip angle search range, and calculating azimuth angles associated with individual dip angles; c) comparing the calculated azimuth angles with the reference azimuth angle, and finding one azimuth angle, which is closest to the reference azimuth angle, among the calculated azimuth angles; and d) setting the dip angle applied to the closest azimuth angle to a specific dip angle associated with a corresponding azimuth angle, such that a more accurate azimuth angle can be detected by the on the basis of the calculated dip angle.

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 processor 52 amplifies signals Sx and Sy, and controls an offset voltage and amplitude A generated during an amplification process. An analog/digital (AD) converter 53 converts analog signals Vadcx and Vadcy from the analog signal processor 52 into a digital signal. A digital signal processor 54 measures a maximum value Vadc—max and a minimum value Vadc—min associated with the digital signal from the AD converter 53, and outputs, to the analog signal processor 52, an offset control signal Soc and a gain control signal Sgc based on the maximum value Vadc—max and minimum value Vadc—min. The signal processor can maintain levels of signals, to be inputted into the AD converter, to be within a reference voltage range.

Abstract: An automatic calibration method for use in an electronic compass. Using the automatic calibration method, the electronic compass automatically calculates and corrects offset and scale values of a geomagnetic signal by detecting one rotation of a geomagnetic axis during a predetermined period of time. The electronic compass calculates an azimuth angle upon receiving geomagnetic data from the geomagnetic sensor, and finds maximum and minimum values of sensor signals of individual axes of the geomagnetic sensor using the received geomagnetic data such that it can correct or calibrate deviation of the azimuth angle. When a time consumed for calibration is the same or shorter than a maximum calibration effective time, the electronic compass determines whether a current state of the detected entry signal indicates a predetermined steady-state flow.

Abstract: 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. In the signal processor, an analog signal processor 52 amplifies signals Sx and Sy, and controls an offset voltage and amplitude A generated during an amplification process. An analog/digital (AD) converter 53 converts analog signals Vadcx and Vadcy from the analog signal processor 52 into a digital signal. A digital signal processor 54 measures a maximum value Vadc—max and a minimum value Vadc—min associated with the digital signal from the AD converter 53, and outputs, to the analog signal processor 52, the offset control signal Soc and the gain control signal Sgc based on the maximum value Vad—max and minimum value Vadc—min. The signal processor can maintain levels of signals, to be inputted into the AD converter, to be within a reference voltage range.