Sensitivity and noise of a lateral bipolar magnetotransistor in CMOS technology

An investigation of the magnetic field sensitivity and noise properties of a novel magnetotransistor structure is reported. The device is reminiscent of a long-channel NMOS transistor operated in the lateral bipolar mode, with an accelerating field in the base region. An approximate analysis of the sensitivity is made. Sensitivities as high as 1.5 T^-1are measured. The equivalent input magnetic field noise density is below 0.4 × 10^-6T/√Hz for frequencies as low as 10 Hz and total current of 0.6 mA.