Temperature coefficient of resolution of lateral bipolar magnetotransistors

The authors present measurement results of the temperature coefficient (TC) of magnetic field resolution B_min for dual-collector lateral bipolar magnetotransistors (MTs)-over a temperature range 273 K⩽T⩽373 K. For a bandwidth of 500 Hz centered around 750 Hz, the resolution turns out to be 600 nT at room temperature with a TC of +2.3×10^-3/K. With the MT operating in medium injection, there is very little dependence of B _min on bias conditions. In this regime, the correlation (Γ) between collector noise currents is the highest (near unity), where the forward current gain β of the MT is at its maximum. At higher injection levels, a degradation in Γ is observed, possibly due to emitter crowding effects, behaving in a manner similar to β. The degree of coherence appears to be dependent on frequency; Γ is higher at low frequencies where the base 1/f noise predominates and Γ degrades at higher frequencies when white noise levels from the collector epi region become significant