ICHAUS IC-MZ Differential hall switch Datasheet

iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 1/12
FEATURES
APPLICATIONS
♦
♦
♦
♦
♦ Gear wheel sensing
♦ Pole wheel and magnetic tape
scanning
♦ Magnetic incremental encoders
♦ Proximity switches
♦ Two-channel line drivers up to
100 kHz
♦
♦
♦
♦
♦
♦
♦
♦
Dual Hall sensors set 2.0 mm apart
Magnetic field frequency range from DC to 40 kHz
Supply voltage range 4.5 to 36 V
Complementary push-pull line driver outputs with integrated
line adaptation
Output stages are current limited and short-circuit-proof due to
temperature shutdown
Min. 200 mA output current at 24 V supply voltage
Low driver stage saturation voltage (< 0.4 V at 30 mA)
RS422-compatible (TIA / EIA standard)
Temperature and supply voltage monitor with error messaging
Amplified differential sensor signal, accessible for diagnostic
purposes
Additional mode of operation (twofold line driver)
Temperature range from -40°C to 125°C (Option: -55°C)
PACKAGES
DFN10 4 mm x 4 mm
BLOCK DIAGRAM
4.5 ... 36 V
VB
D
ND
LINE
VPA
A
NA
NERR
TEST
GND1
Copyright © 2013 iC-Haus
GND2
http://www.ichaus.com
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 2/12
DESCRIPTION
Hall-effect device iC-MZ is a differential magnetic
sensor used to scan pole wheels or ferromagnetic
gear wheels. It contains two Hall sensors set 2.0 mm
apart, a differential amplifier with a back-end comparator and a complementary line driver. A difference
in field strength of the magnetic normal components
at iC-MZ’s two Hall elements is amplified and evaluated as an analog signal and fed to the integrated
line drivers as a complementary digital signal. The
digital output signal tracks the change in sign of the
field strength difference with a given hysteresis and
thus provides a clear switch.
switched to high impedance. Following a delay of
about 200 µs the analog outputs are activated and
the status of the two Hall sensors ist transmitted by
the line drivers if the difference in field strength is sufficiently strong.
With a moving gear or pole wheel the frequency of
the tooth or pole pair corresponds to the frequency
of the output signal. The amplified analog differential
sensor signal is available for diagnostic purposes at
pins A and NA.
By activating the TEST input the device can be used
as an independent two-channel line driver. In this
case, the outputs D and ND are controlled by the inputs A and NA.
Once the device has been switched on the digital outputs are initially in a predefined start state with D at
low and ND at high; the analog outputs A and NA
The complementary line drivers are suitable for supply voltages of 4.5 to 36 V with output impedances
between 40 and 110 Ω. An integrated over temperature and undervoltage monitor switches the output
stages to high impedance in the event of error and
activates the open drain output NERR.
The analog section of the iC-MZ circuit is fed by an
internal supply of 5 V which is available at pin VPA
for reference purpose. To improve signal quality, a
capacitor can be connected to this pin.
PACKAGING INFORMATION
PIN CONFIGURATION DFN10
1
10
2
3
4
PIN FUNCTIONS
No. Name Function
9
iC-MZ
...
...yyww
5
8
7
6
EP
1
2
3
4
5
6
7
8
9
10
EP
GND1
D
VB
ND
GND2
TEST
NERR
VPA
NA
A
Ground
Digital Output, not inverted
Supply Voltage
Digital Output, inverted
Ground
Linedriver Test Mode
Error Output, open drain
Internal 5 V Supply Voltage
Analog Output, invertiert
Analog Output, non invertierend
Exposed Pad
GND1 and GND2 have to be tied together to a common ground. Connect the Exposed Pad EP to this common
ground. Use a large ground plane to improve thermal performance. EP is not intended as an electrical connection
point. Orientation of the logo ( MZ CODE ...) is subject to alteration.
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 3/12
PACKAGE DIMENSIONS
All dimensions given in mm.
RECOMMENDED PCB-FOOTPRINT
3.20
5
17
R0.
0.65
0.35
BOTTOM
4
3.10
0.65
0.30
4.10
0.40
4
2.70
TOP
0.65
2.80
0.90
SIDE
dra_dfn10-1_pack_1, 10:1
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 4/12
ABSOLUTE MAXIMUM RATINGS
Beyond these values damage may occur; device operation is not guaranteed. Absolute Maximum Ratings are no Operating Conditions.
Integrated circuits with system interfaces, e.g. via cable accessible pins (I/O pins, line drivers) are per principle endangered by injected
interferences, which may compromise the function or durability. The robustness of the devices has to be verified by the user during system
development with regards to applying standards and ensured where necessary by additional protective circuitry. By the manufacturer
suggested protective circuitry is for information only and given without responsibility and has to be verified within the actual system with
respect to actual interferences.
Item
No.
Symbol
Parameter
Conditions
Unit
Min.
Max.
G001 VB
Supply Voltage
-0.4
40
V
G002 V()
Voltage at D, ND, NERR
-0.4
40
V
G003 V()
Voltage at A, NA, TEST
-0.4
6
V
G004 I(VB)
Current in VB
-100
100
mA
G005 I()
Current in D, ND
-600
600
mA
G006 I(NERR)
Current in NERR
-10
30
mA
G007 I()
Current in A, NA, TEST
-4
4
mA
G008 Vd()
Susceptibility to ESD at all pins
1
kV
G009 Tj
Operating Junction Temperature
-55
150
°C
G010 Ts
Storage Temperature Range
-55
150
°C
HBM 100 pF discharged through 1.5 kΩ
THERMAL DATA
Operating Conditions: VB = 4.5..36 V, unless otherwise stated
Item
No.
T01
Symbol
Parameter
Conditions
Unit
Min.
Ta
Operating Ambient Temperature Range
Extended Temperature Range (Option -ET)
T02
Rtjc
Thermal Resistance Chip/Case
T03
Rthja
Thermal Resistance Chip/Ambient
Mounted on PCB, with thermal pad of 2 cm2
All voltages are referenced to ground unless otherwise stated.
All currents flowing into the device pins are positive; all currents flowing out of the device pins are negative.
Typ.
-40
-55
Max.
+125
+125
°C
°C
10
K/W
40
K/W
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 5/12
ELECTRICAL CHARACTERISTICS
Operating Conditions: VB = 4.5..36 V, Tj = -55...135 °C unless otherwise stated
Item
No.
Symbol
Parameter
Conditions
Unit
Min.
Typ.
Max.
General
001
fmagn
Magnetic Cut-off Frequency
002
VB
Permissible Supply Voltage
(upper 3 dB frequency corner)
003
I(VB)
Supply Current in VB
open outputs, fmagn = 0
004
|Hdc |
Magnitude of mean magnetic
field strength
|Hdc | = |H1 + H2 | / 2,
Outputs A, NA not saturated
005
|∆H|
Maximal magnetic field difference |∆H| = |H1 − H2 |
006
Ht,hi
Upper magnetic trigger threshold Output D lo → hi for ∆H > Ht,hi
007
Ht,lo
lower magnetic trigger threshold
008
Ht,hys
Hysteresis
009
Vc()lo
Clamp Voltage lo at Pins VB,
I() = -10 mA
VPA, VPD, A, NA, D, ND, NERR,
TEST
010
Vc()hi
Clamp Voltage hi at Pins VB,
NERR
011
Vc()hi
012
013
40
4.5
9
kHz
36
V
12
mA
400
kA/m
120
kA/m
2
kA/m
Output D hi → lo for ∆H < Ht,lo
-2
kA/m
Ht,hys = Ht,hi − Ht,lo
4
kA/m
-1.4
-0.35
V
I(VB) = 10 mA, Test = hi, I(NERR) = 1 mA
37
55
V
Clamp Voltage hi at Pins VPA,
VPD, A, NA, TEST
I(VPA, VPD) = 10 mA, I(A, NA, TEST) = 2 mA
6
20
V
tsetup
System enable
from power on to activating outputs
I(VB)
Supply Current in VB, Test Mode open outputs, Test = hi (line driver mode)
200
400
µs
6
mA
Temperatur Monitor
301
Toff
Thermal Shutdown Threshold
145
175
°C
302
Ton
Thermal Lock-on Threshold
135
165
°C
303
Thys
Thermal Shotdown Hysteresis
20
°C
kΩ
Thys = Ton - Toff
5
10
Differential Outputs A, NA, Line Driver Test Mode
501
Rout()
Output resistance
503
Vdc()
Mean output voltage
∆H = 0
14
20
28
1.5
1.8
2.1
504
|∆V()|
Output voltage difference
|∆H| = 1kA/m, |∆V()| = |V(A) − V(NA)|
505
Vt()hi
Input Threshold Voltage hi
TEST = hi (Leitungstreibermodus)
506
Vt()lo
Input Threshold Voltage lo
TEST = hi (Leitungstreibermodus)
0.8
507
Vt()hys
Input Hysteresis
TEST = hi (Leitungstreibermodus)
0.2
508
Ipd()
Pull-Down Current
V() = 0.8 V, TEST = hi
509
Ipd()
Pull-Down Current
V() = 5.5 V, TEST = hi
70
V
mV
2
V
V
0.4
0.6
V
10
100
µA
20
200
µA
Error Output NERR
601
Vs()lo
Saturation Voltage lo at NERR
602
Isc()lo
Short-Circuit Current lo in NERR V(NERR) = 2 V...VB, NERR = lo
I(NERR) = 2.5 mA, NERR = lo
603
Ilk()
Leakage Current in NERR
V(NERR) = 5.5 V...VB, NERR = hi
-10
604
VB
Supply Voltage VB for NERR
Function
I(NERR) = 2.5 mA, NERR = lo,
Vs(NERR) < 0.4 V
3.2
605
Rpu()
Pull-Up-Resistor at NERR
V(NERR) = 0...4.5 V
1
2.5
5.5
MΩ
Test Mode = off, V(TEST) ≤ VPA
11
20
36
kΩ
2
V
4
12
0.4
V
25
mA
10
µA
V
Test Mode NERR, TEST
704
Rpd(TEST) Pull-Down Resistor at TEST
710
Vt(TEST)hi Threshold Voltage hi at TEST
711
Vt(TEST)lo Threshold Voltage lo at TEST
0.8
712
Vt(TEST)hy Hysteresis
0.2
713
Vt(NERR)hi Threshold Voltage hi at NERR
Test = hi
V
0.4
0.6
V
2.5
V
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 6/12
ELECTRICAL CHARACTERISTICS
Operating Conditions: VB = 4.5..36 V, Tj = -55...135 °C unless otherwise stated
Item
No.
Symbol
Parameter
Conditions
Unit
Min.
Typ.
Max.
Line Driver D, ND
801
Vs()hi
Saturation Voltage high
Vs()hi = VB - V(),
I() = -10 mA, output = hi
0.2
V
802
Vs()hi
Saturation Voltage high
Vs()hi = VB - V(),
I() = -30 mA, output = hi
0.4
V
803
Isc()hi
Short circuit current high
V() = VB - 1.5 V, output = hi
-70
-50
-35
mA
804
Isc()hi
Short circuit current high
V(Ax) = 0 V, output = hi
-600
805
Rout()hi
Output resistance
VB = 10...36 V, V() =0.5 * VB
40
75
110
806
SR()hi
Slew Rate high
VB= 36 V, Cl() = 100 pF
100
250
807
Vc()hi
Free Wheel Clamp Voltage high
I() = 100 mA,
VB = VCC = GND
0.5
808
Vs()lo
Saturation Voltage low
809
Vs()lo
Saturation Voltage low
810
Isc()lo
Short circuit current low
V() = 1.5 V, output = lo
811
Isc()lo
Short circuit current low
V() = VB, output = low
812
Rout()lo
Output resistance
813
SR()lo
814
815
816
mA
Ω
V/µs
1.3
V
I() = 10 mA, output = lo
0.2
V
I() = 30 mA, output = lo
0.4
V
70
mA
600
mA
35
50
VB = 10...36 V, V() = 0.5 * VB
40
75
Slew Rate low
VB = 36 V, Cl() = 100 pF
100
250
Vc()lo
Free Wheel Clamp Voltage low
I() = -100 mA
-1.3
-0.5
V
Ilk()
Leakage Current in D, ND
VB < VBoff; V() = 0...VBoff
-10
10
µA
Ilk()
Leakage Current in D, ND
T > Toff; V() = 0...VB
-10
10
µA
4.45
V
110
Ω
V/µs
VB Voltage Monitor
901
VBon
Turn-on Threshold VB
902
VBoff
Turn-off Threshold VB
903
VBhys
Hysteresis
VPAhys = VPAon − VPAoff
100
200
907
V(VPA)
Voltage at VPA
VB > 5 V
4.5
5
908
V(VPA)
Voltage at VPA
VB ≤ 5 V
4
3.2
V
mV
5.5
V
5
V
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 7/12
DEFINITION OF MAGNETIC FIELDS AND SENSOR OUTPUT SIGNALS
In essence iC-MZ is non-magnetic and thus has practically no effect on the magnetic field to be scanned.
The Hall sensors on the topside of the chip or at package level (x, y) are sensing the z component Hz of the
magnetic field vector at the site of each sensor.
Magnetic field component Hz counts as a positive
when the field lines emerge on the printed upper side
of the chip.
The source of the magnetic field (magnets, coils) can
be placed above or below (back bias) the iC package.
In accordance with Figure 2 a distinction can be made
between the different position and polarity of a magnet from the sign of the sensor signal. Following the
amplification of the Hall voltage difference a differential analog signal V(A) or V(NA) is available at pins A
and NA with a mean voltage of Vdc (Figure 3).
If ∆H exceeds a limit of Ht,hi , digital output D switches
to high. If ∆H undershoots a threshold of Ht,lo , output
D is switched back to low. The switching status complementary to D is available at output ND.
If differential field strength ∆H lies within the Ht,lo ..Ht,hi
interval, the momentary switching status of the driver
outputs does not change.
M
Z
+B
N
V
M
Z
S
+B
V(A)
N
S
z
Vdc
y
V(NA)
x
Figure 1: Example magnet positions in relation to
iC-MZ
The difference ∆H between z components H1 and H2
of the magnetic field strengths at the site of the two
Hall sensors S1 and S2 is significant for the electrical
output signal.
H
0
Figure 3: Analog signals A and NA as a function of
the difference in field strength ∆H
V(D)
∆H = H1 − H2
Ht,hys = Ht,hi – Ht,lo
S
N
M
Z
S1
S1
H1
H1
S2
Pin 1
Pin 1
H2
z
VB
S
M
Z
N
S2
H2
H>0
H<0
y
Ht,lo
0
Ht,hi
H
x
Figure 2: Definition of the difference in field strength
∆H
Figure 4: Digital output D in dependence on the difference in field strength ∆H
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 8/12
HALL SENSOR POSITION
The position of the two Hall sensors S1 and S2 is
shown in Figure 5 (top view).
0.4 typ.
z
x
side view
2,0
|
S2
|
S1
| < 0.2
0,14
| < 0.2
S1
y
S2
x
center of chip
center
of chip
|
| < 3°
y
Figure 5: Position of Hall sensors S1 and S2 in relation to the chip center (dimensions in mm)
x
top view
Figure 6: Maximum placement error of the chip (exaggerated view) in a DFN10 package (dimensions in mm)
The position tolerances of the chip within the DFN10
package are given in Figure 6.
LINE DRIVER MODE
iC-MZ’s line driver mode is activated by TEST = high,
i.e. by a supply of VPA = 5 V. Pins A and NA then function as independent inputs for line driver outputs D and
ND. When pins A and NA are connected together and
used as common input, D and ND acts as buffered and
inverted outputs.
4.5 ... 36 V
VB
SUPPLY
HALL SENSOR
AMPLIFIER
A/D
LINE DRIVER
D
B
B
ND
LINE
VPA
5V
ANALOG BUFFER
A
NA
TEMPERATUR MONITOR
ERROR CONTROL
NERR
1
TEST
> 145 °C
5V
Rpu
TEST
iC-MZ
GND1
GND2
Figure 7: iC-MZ in line driver mode
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 9/12
APPLICATON NOTES
The complementary line driver couples the output signals via lines to industrial 24 V systems. Due to the
possible event of short circuiting in the line the drivers
are current limited and shut down with excessive temperature. The maximum possible signal frequency depends on the capacitive loading of the outputs (line
length) or the power dissipation in iC-MZ caused by
such. With an unloaded output the maximum output
voltage is equivalent to supply VB - with the exception
of the saturation voltages.
40
36
VB = 36 V
32
V(D, ND) [V]
28
24
20
16
LINE EFFECTS
With 24 V signals data is often transmitted without
the line beeing terminated with the characteristic
impedance. Mismatched line terminations such as
these cause reflections which travel back and forth if
no suitable adjustments have been made at the driver
end of the setup. With rapid pulse trains transmission
is then disrupted.
In iC-MZ the reflection of return signals is hindered by
an integrated impedance adapter. On pulse transmission the amplitude at the iC-MZ output first rises to approximately half the value of supply voltage VB as the
internal driver resistor and the line impedance adapter
form a voltage divider. Following a delay determined by
the length of the line the impedance coupled into the
line in this way is reflected at the high impedance end
of the setup and travels back towards the driver. As the
latter is well adjusted to the line by its interior resistor,
the return pulse is largely absorbed. Fast signals can
thus also be transmitted in this manner along lines with
a characteristic impedance of between 40 and 110 Ω.
12
VB = 24 V
8
4
0
0
100
200
300
400
500
- I(D, ND) [mA]
Figure 8: Load dependence of the output voltage
Figure 8 illustrates the typical highside output characteristics of a driver acting as a load for two different
supply voltages. Across a wide range the differential
output resistance is typically 75 Ω.
BOARD LAYOUT
The thermal dissipation of iC-MZ is improved by connecting the thermal pad on the underside to a large
area of copper on the board. Blocking capacitors used
to filter the local iC supply should be connected up
to the VB and GND package pins across the shortest
possible distance.
NERR connection
Excessive temperature and overvoltage errors are indicated at output NERR. In normal operating mode the
pin is at high impedance (open drain); it is switched
to GND in the event of error. It can be connected up
to VB via an external resistor. If NERR is not used, it
must be left open and not be connected to GND.
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 10/12
APPLICATION EXAMPLES
Gear wheel scanning
Logging the position and rotation of a gear wheel with
iC-MZ requires that the gear wheel is made of a soft
magnetic basic material with which a magnetic field
applied externally through the gear geometry can be
modulated. The strength of the modulation is greatest
at the gear rim, calling for iC-MZ to be placed at the
shortest possible operating distance to the gear wheel.
The necessary external bias field is generated by a
back bias magnet placed behind iC-MZ. The magnet
should be positioned central to the package so that the
two Hall sensors are impinged by equal magnetic field
strengths and a field strength offset is avoided; the latter would make a greater difference in modulation field
strength necessary for switching purposes. Field homogeneity can be improved by placing a pole piece
between the magnet and iC-MZ.
gear wheel
P
B1
B2
S1
iC-MZ
S2
N
S
bias magnet
B
B2
bias
field
B1
B1-B2
The strength of the magnetic field modulation depends
not just on the operating distance and the intensity of
the bias field but also on the module and addendum
of the gear wheel. The distance of the teeth along the
perimeter of the wheel stipulates the cycle with which
the magnetic field strength is modulated. An optimum
modulation depth is achieved when the gear wheel geometry is selected so that the two Hall sensors on the
chip are opposite a tooth or a gap and the sensors provide signals in antiphase. With the given iC-MZ sensor
distance of 2 mm a tooth distance of about 4 mm is advantageous but not imperative. Even if the geometry of
the wheel is not adapted to suit the sensor, the signals
generated by the two Hall sensors share a fixed phase
relation.
Figure 9 illustrates the typical course of magnetic induction B = µ0 · H at the two Hall sensors, dependent
on angle of rotation φ of the gear wheel. In an ensuing
amplification process analog signals VA and VNA are
formed from the differential signal; digital signals VD
and VND are generated by the back-end comparator
with hysteresis.
P
BT,hi
BT,l o
0
V
P/2
VNA
0
3P/2
VA
P/2
Vdc
P
VD
3P/2
VB
P/2
VND
P
3P/2
P
3P/2
VB
P/2
Figure 9: Gear wheel scanning
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 11/12
Pole wheel scanning
Pole wheels have a cyclic magnetization along their
perimeter which is used for the magnetic modulation
of iC-MZ. The intensity of the magnetic field is greatest along the perimeter and significantly diminishes
with an increase in distance , so that iC-MZ should be
placed as close to the pole wheel as possible.
pole wheel
P
SS N
N
The magnetic subdivision along the pole wheel
perimeter is repeated by a cycle P; iC-MZ’s electrical
output signals also demonstrate this periodicity. The
pole wheel is optimally adjusted when the Hall sensors are activated in antiphase, i.e. the distance of the
Hall sensors is equivalent to just half a magnetic cycle.
With iC-MZ this is the case when P = 4 mm.
B1
S1
S2
iC-MZ
B2
B
B1
B2
P
3P/2
P/2
The dimensions of a pole wheel and its magnetic subdivision are often stipulated by the application so that
the signals provided by the two Hall sensors are no
longer in antiphase but in an arbitrary yet fixed phase
relation to one another.
B1-B2
P
BT,hi
BT,l o
0
V
P/2
VA
0
3P/2
VNA
P/2
Vdc
The differential signal and the analog and digital iC-MZ
output signals derived from it in dependence on the angle of rotation of a pole wheel are shown in Figure 10.
3P/2
P
VD
VB
P/2
P
VND
3P/2
VB
P/2
P
3P/2
Figure 10: Pole wheel scanning
iC-Haus expressly reserves the right to change its products and/or specifications. An info letter gives details as to any amendments and additions made to the
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email.
Copying – even as an excerpt – is only permitted with iC-Haus’ approval in writing and precise reference to source.
iC-Haus does not warrant the accuracy, completeness or timeliness of the specification and does not assume liability for any errors or omissions in these
materials.
The data specified is intended solely for the purpose of product description. No representations or warranties, either express or implied, of merchantability, fitness
for a particular purpose or of any other nature are made hereunder with respect to information/specification or the products to which information refers and no
guarantee with respect to compliance to the intended use is given. In particular, this also applies to the stated possible applications or areas of applications of
the product.
iC-Haus conveys no patent, copyright, mask work right or other trade mark right to this product. iC-Haus assumes no liability for any patent and/or other trade
mark rights of a third party resulting from processing or handling of the product and/or any other use of the product.
iC-MZ
DIFFERENTIAL HALL SWITCH
Rev B1, Page 12/12
ORDERING INFORMATION
Type
Package Options
iC-MZ DFN10
iC-MZ DFN10
Order Designation
extended temperature range
-55°C ... 125°C
iC-MZ DFN10
iC-MZ DFN10 ET -55/125
For technical support, information about prices and terms of delivery please contact:
iC-Haus GmbH
Am Kuemmerling 18
D-55294 Bodenheim
GERMANY
Tel.: +49 (0) 61 35 - 92 92 - 0
Fax: +49 (0) 61 35 - 92 92 - 192
Web: http://www.ichaus.com
E-Mail: [email protected]
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