Datasheet

HMC1501/1512
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Basic Sensor Bridge Schematic
Both the HMC1501 and HMC1512 are designed to be used in saturation mode, with applied fields of 80 Oerstads or
greater, required to meet the specifications in this datasheet. The HMC1501 contains one bridge and the HMC1512 has
two identical bridges, coexisting on a single die. Bridge B is physically rotated 45° from bridge A. The HMC1501 has a
sensor output of V = - Vb*S sin (2 ), and the HMC1512 has a sensor output of V = Vb*S sin (2 ) for sensor A and
sensor B’s output is V = -Vb*S cos (2 ). Vb is the supply voltage, and S is a sensor constant determined by the
materials. For these Honeywell sensors, S is typically 12mV/V.
APPLICATION NOTES
The HMC1501 and HMC1512 are Honeywell’s AMR based magnetic position sensors that contain AMR sensor bridges to
be used in saturation mode. The HMC1501 contains one AMR bridge for a 45° range of position sensing, and the
HMC1512 contains two AMR bridges for a 90° range of position sensing. The bridge differential output voltage ( V) for
the HMC1501 is:
V = -Vs S sin (2 ) where:
Vs = Supply Voltage (volts)
S = Material Constant (12mV/V)
= Reference to Magnetic Field Angle (degrees)
With the bridges on the HMC1512 oriented 45° in rotation from each other, the differential output voltage for sensor
bridge A is:
V
A
= Vs S sin (2 )
And for sensor bridge B, the differential output voltage is:
V
B
= -Vs S cos (2 )
+
-
V
+
-
V
b
R- R
R- R
R+ R
R+ R
I
I
I
I
M M
M
M
Applied Field Direction
Vb
GND
+
-
V
+
-
V
b
R- R
R- R
R+ R
R+ R
I
I
I
I
M M
M
M
Applied Field Direction
Vb
GND