IC-PMX Datasheet, PDF (17/27 Pages) IC-Haus GmbH – ENERGY HARVESTING MULTITURN COUNTER/ENCODER

iC-PMX
ENERGY HARVESTING MULTITURN COUNTER/ENCODER
POSITION OF THE HALL SENSORS AND THE SENSOR SIGNAL PROCESSING
Pin 1 Mark
N
H0
H3
H5
Rev A3, Page 17/27
S
H4
H1
H2
(top view)
C1130802
Figure 6: Position of the Hall Sensors
z
y
B
+B_z
x
-B_z
C151107-1
Figure 7: Sensor Principle
Phase Sequence Hall Switch
The Hall data for the Wiegand pulse evaluation is ac-
quired with the sensors H4 and H5 (see fig. 6). Dimen-
sional drawings for the two packages can be found on
page 5 and page 6. Those Hall sensors are evaluated
when a Wiegand pulse occurs to detect the rotation
direction (DIR).
The magnetic field strength at sensor H4 and H5 can
be derived from the magnetic field strength of the single
turn hall sensors H0-H3:
H₄
=H₁ +
H₃ − H₁ + H₂ − H₀
28
H₅
=H₃ −
H₃ − H₁ + H₂ − H₀
28
iC-PMX can measure the differential magnetic field
strength between the Hall sensors H4 and H5 or the
absolute magnetic field strength at Hall sensor H4. Pin
C2 is used to choose between those two options. (See
page 13: Set C2=0 for differential measurement.)
The magnetic field strength is amplified and compared
against three internal thresholds (see el. char. 401, 402,
403). Pin C3 is used to select the desired magnetic
polarity thresholds.^†
The rotation direction depends on the Wiegand pulse
polarity and the threshold Ht() if pin C3 is low. (See
fig. 8, the magnetic field strength during the sensor
evaluation must be outside of the specified threshold
limits, otherwise the signal has an arbitrary value.)
If pin C3 is high, the rotation direction depends on the
thresholds Ht()pos, Ht()neg and the Wiegand pulse po-
larity. The threshold Ht()neg is used to determine the
rotation direction while the Wiegand pulse polarity is
negative (PP = 0). The threshold Ht()pos is used to de-
termine the rotation direction while the Wiegand pulse
polarity is positive (PP = 1). Fig. 9 shows the required
magnetic field strength for pin C2=0 and pin C3=1.
- Wiegand pulse (PP=0)
Counterclockwise (DIR=0)
H > 10 kA/m
90°
M _{0° + Wiegand pulse (PP=1)}
Clockwise (DIR=1)
J ^{H > 10 kA/m}
- Wiegand pulse (PP=0)
Counterclockwise (DIR=0)
H > -5 kA/m
90°
M _{0° + Wiegand pulse (PP=1)}
Clockwise (DIR=1)
J ^{H > 40 kA/m}
- Wiegand pulse (PP=0)
Clockwise (DIR=1)
H < -10 kA/m L
a _{180° K}
+ Wiegand pulse (PP=1)
Counterclockwise (DIR=0)
H < -10 kA/m
270°
- Wiegand pulse (PP=0)
Clockwise (DIR=1)
H < -40 kA/m L
a _{180° K}
+ Wiegand pulse (PP=1)
Counterclockwise (DIR=0)
H < 5 kA/m
270°
Figure 8: Required Magnetic Field Strength during
Wiegand pulses for pin C3=0
(see el. char. 402)
Figure 9: Required Magnetic Field Strength during
Wiegand pulses for pin C2=0, pin C3=1
(see el. char. 401, 403)
† _{For iC-PMX 4: Please read the design review on p. 25}