Philips Magnetoresistive Sensor - Manual (Page 27)

2000 Sep 06 27
Philips Semiconductors
Magnetoresistive sensors for
magnetic field measurement
General
The simplest form of temperature compensation is to use
a current source to supply to the sensor instead of a
voltage source. In this case, the resulting reduction in
sensitivity due to temperature is partially compensated by
a corresponding increase in bridge resistance.
Thus a current source not only improves the stability of the output voltage ‘V
o
’, and reduces the variation in sensitivity
to a factor of approximately 1.5 (compared to a factor of
three using the voltage source). However, this method
requires a higher supply voltage, due to the voltage drop
of the current source.
Fig.32 Output voltage ‘V
o
’ of a KMZ10B sensor as a function of transverse field ‘H
y
’ using a current source, for
several temperatures.
handbook, full pagewidth
0
75
4 2
MLC135
25
50
50
25
75
2 0 4
H (kA/m) y
VO
(mV/V)
T = 25 C amb
o
25 C
o
75 C
o
125 C
o
operating range