Measurement and modelling of sensitivity and noise of MOS magnetic field-effect transistors

A novel 0.7 V high sensitivity complementary differential MAGFET sensor for contactless mechatronic applications

“…Some authors (Rodrigo model) [18] consider it to be dependent only on Hall mobility, considering the extended Hall mobility model given by (4). Other authors [19] have provided a linear model with geometrical correction. In addition, for a given sensitivity large steered sensing currents ( in and ip) require high MAGFET bias currents.…”

“…A CDMAGFET SPICE model incorporating approximate values of base relative current sensitivities S RN and S RP for the NMAGFET and the PMAGFET, respectively, were used to perform this voltaic sensitivity comparison. The Hall mobility, and the sensitivity coefficients for channel-size and MAGFET geometry (L, W, D), as well as the bias voltages (V GS and V DS ) are considered in the model to generate a linear approximation [19] of S RN and S RP . The circuit in Fig.…”

“…To compare the performance with the previous NMOS only MAGFET and the single-ended CCMAGFET the same topology was used, but with one of the differential amplifier inputs held at the input DC common-mode voltage. Based on the device channel sizes and the bias voltages (V DD = 0.7 V, V GSN = 0.2 V, V GSP = −0.3 V, V DSN = 0.4 V and V DSP = −0.4 V) the theoretical linearly approximated current sensitivities following [19] are S RN ≈ 3.623%/T and S RP ≈ 0.5%/T. Fig.…”

“…The VCCS coupling constant (a transconductance) is thus 2.88 for the NMAGFET (Kn = 2.88) and 0.4 for the PMAGFET (Kp = 0.4). A parasitic resistance of around 10 M [19] is assumed between the PMAGFET and the NMAGFET split drains with an overall value of 5 M added between the two cross-connected drain nodes in the model using a series connection of two 2.5 M elements. How closely this SPICE model fits the performance on silicon implementation mostly depends on the actual coupling constant values based on the sensitivities specific to the fabrication process technology (particularly doping) and the MAGFET geometry.…”

SPICE modeling of a precise two-dimensional MOS magnetic sensor

“…To characterize the operation and to optimize the structure of MOSFET magnetic sensor, analytical and numerical models had been developed [14][15][16][17][18][19][20][21][22][23]. The accuracy of these models is measured by its ability to model accurately the transfer of the variations of magnetic fields to current (voltage) variations in the active devices while the computational efficiency of them can be measured by the CPU time required to generate the results.…”