3059
AND
3060
HALL-EFFECT
GEAR-TOOTH SENSORS
—AC COUPLED
3059
AND
3060
The UGN/UGS3059KA and UGN/UGS3060KA ac-coupled Hall-
effect gear-tooth sensors are monolithic integrated circuits that switch
in response to changing differential magnetic fields created by moving
ferrous targets. These devices are ideal for use in non-zero-speed,
gear-tooth-based speed, position, and timing applications such as in
anti-lock braking systems, transmissions, and crankshafts.
Both devices, when coupled with a back-biasing magnet, can be
configured to turn ON or OFF with the leading or trailing edge of a
gear-tooth or slot. Changes in fields on the magnet face caused by a
moving ferrous mass are sensed by two integrated Hall transducers
and are differentially amplified by on-chip electronics. This differential
sensing design provides immunity to radial vibration within the devices’
operating air gaps. Steady-state magnet and system offsets are
eliminated using an on-chip differential band-pass filter. This filter also
provides relative immunity to interference from RF and electromag-
netic sources. The on-chip temperature compensation and Schmitt
trigger circuitry minimizes shifts in effective working air gaps and
switch points over temperature, allowing operation to low frequencies
over a wide range of air gaps and temperatures.
Each Hall-effect digital Integrated circuit includes a voltage regu-
lator, two quadratic Hall-effect sensing elements, temperature com-
pensating circuitry, a low-level amplifier, band-pass filter, Schmitt
trigger, and an open-collector output driver. The on-board regulator
permits operation with supply voltages of 4.5 to 24 volts. The output
stage can easily switch 20 mA over the full frequency response range
of the sensor and is compatible with bipolar and MOS logic circuits.
The two devices provide a choice of operating temperature
ranges. Both devices are packaged in a 5-pin plastic SIP.
Data Sheet
27612.20*
HALL-EFFECT GEAR-TOOTH SENSORS
—AC COUPLED
X
X
V
CC
1
2
3
4
5
GROUND
FILTER
SUPPLY
OUTPUT
Dwg. PH-011
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
at T
A
= +25
°
C
Supply Voltage, V
CC
.............................
24 V
Reverse Battery Voltage, V
RCC
..........
-30 V
Magnetic Flux Density, B ............
Unlimited
Output OFF Voltage, V
OUT
....................
24 V
Output Current, I
OUT
.........................
25 mA
Package Power Dissipation,
P
D
............................................
500 mW
Operating Temperature Range, T
A
Prefix ‘UGN’ .................
-20
°
C to +85
°
C
Prefix ‘UGS’ ...............
-40
°
C to +125
°
C
Storage Temperature Range,
T
S
...............................
-65
°
C to +150
°
C
FILTER
FEATURES
s
Senses Motion of Ferrous
Targets Such as Gears
s
Wide Operating Temperature Range
s
Operation to 30 kHz
s
Resistant to RFI, EMI
s
Large Effective Air Gap
s
4.5 V to 24 V Operation
s
Output Compatible With
All Logic Families
s
Reverse Battery Protection
s
Resistant to Physical Stress
Always order by complete part number, e.g.,
UGS3060KA
.
3059
AND
3060
HALL-EFFECT
GEAR-TOOTH SENSORS
—AC COUPLED
1
SUPPLY
FUNCTIONAL BLOCK DIAGRAM
REG
OUTPUT
2
+
-
X
X
4
FILTER
3
GROUND
5
FILTER
Dwg. FH-008
ELECTRICAL CHARACTERISTICS over operating temperature range.
Limits
Characteristic
Supply Voltage
Output Saturation Voltage
Output Leakage Current
Supply Current
High-Frequency Cutoff
Output Rise time
Output Fall time
Symbol
V
CC
V
OUT(SAT)
I
OFF
I
CC
f
coh
t
r
t
f
Test Conditions
Operating
I
OUT
= 20 mA, B > B
OP
V
OUT
= 24 V, B < B
RP
V
CC
= 18 V, B < B
RP
-3 dB
V
OUT
= 12 V, R
L
= 820
Ω
V
OUT
= 12 V, R
L
= 820
Ω
Min.
4.5
—
—
—
30
—
—
Typ.
—
130
—
11
—
0.04
0.18
Max.
24
400
10
20
—
0.2
0.3
Units
V
mV
µA
mA
kHz
µs
µs
MAGNETIC CHARACTERISTICS over operating temperature and supply voltage ranges
Part Numbers*
Characteristic
Operate Point, B
OP
Release Point, B
RP
Hysteresis, B
hys
Test Conditions
Output switches OFF to ON
Output switches ON to OFF
B
OP
- B
RP
Min.
10
-100
—
3059
Typ.
65
-65
130
Max.
100
-10
—
Min.
5.0
-35
—
3060
Typ.
15
-15
30
Max.
35
-5.0
—
Units
G
G
G
NOTES: * Complete part number includes a prefix to identify operating temperature range (UGN or UGS) and the package suffix KA.
Magnetic switch points are specified as the difference in magnetic fields at the two Hall elements.
As used here, negative flux densities are defined as less than zero (algebraic convention).
Typical values are at T
A
= 25°C and V
CC
= 12 V.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
3059
AND
3060
HALL-EFFECT
GEAR-TOOTH SENSORS
—AC COUPLED
TYPICAL OPERATING CHARACTERISTICS
SWITCH POINTS
100
V
CC
20
=8V
DIFFERENTIAL FLUX DENSITY IN GAUSS
50
DIFFERENTIAL FLUX DENSITY IN GAUSS
OPERATE POINT
3059
OPERATE POINT
3060
10
UGN/UGS3060KA
I
OUT
= 20 mA
T
A
= +25°C
0
0
-50
3060
RELEASE POINT
3059
-10
RELEASE POINT
-100
-50
-20
-25
0
25
50
75
100
125
150
0
5
10
15
20
25
AMBIENT TEMPERATURE IN
°C
Dwg. GH-056
SUPPLY VOLTAGE IN VOLTS
Dwg. GH-057
OUTPUT SATURATION VOLTAGE
300
200
I
OUT
= 20 mA
V
CC
= 12 V
I
OUT
= 20 mA
T
A
= +25°C
SATURATION VOLTAGE IN mV
200
SATURATION VOLTAGE IN mV
150
100
100
0
-50
50
-25
0
25
50
75
100
125
150
0
5
10
15
20
25
AMBIENT TEMPERATURE IN
°C
Dwg. GH-029-1
SUPPLY VOLTAGE IN VOLTS
Dwg. GH-055
3059
AND
3060
HALL-EFFECT
GEAR-TOOTH SENSORS
—AC COUPLED
TYPICAL OPERATING CHARACTERISTICS
SUPPLY CURRENT
20
13
T
A
= +25°C
V
CC
= 18 V
12
SUPPLY CURRENT IN mA
15
SUPPLY CURRENT IN mA
B < B
RP
B
≤
B
RP
11
10
10
5
9
0
-50
8
-25
0
25
50
75
100
125
150
0
5
10
15
20
25
AMBIENT TEMPERATURE IN
°C
Dwg. GH-028-1
SUPPLY VOLTAGE IN VOLTS
Dwg. GH-031-1
APPLICATIONS INFORMATION
A gear-tooth sensing system consists of the sensor
IC, a back-biasing magnet, and a target. The system
requirements are usually specified in terms of the effective
working air gap between the package and the target (gear
teeth), the number of switching events per rotation of the
target, temperature and speed ranges, minimum pulse
duration or duty cycle, and switch point accuracy. Careful
choice of the sensor IC, magnet material and shape,
target material and shape, and assembly techniques
enables large working air gaps and high switch-point
accuracy over the system operating temperature range.
Naming Conventions.
With a south pole in front of
the branded surface of the sensor or a north pole behind
the sensor, the field at the sensor is defined as positive.
As used here, negative flux densities are defined as less
than zero (algebraic convention), e.g., -100 G is less than
-50 G.
Magnet Biasing.
In order to sense moving non-
magnetized ferrous targets, these devices must be back-
biased by mounting the unbranded side on a small
permanent magnet. Either magnetic pole (north or south)
can be used.
The devices can also be used without a back-biasing
magnet. In this configuration, the sensor can be used to
detect a rotating ring magnet such as those found in
brushless dc motors or in speed sensing applications.
Here, the sensor detects the magnetic field gradient
created by the magnetic poles.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3059
AND
3060
HALL-EFFECT
GEAR-TOOTH SENSORS
—AC COUPLED
Figure 1
TYPICAL TRANSFER
CHARACTERISTIC
Sensor Operation.
These sensor ICs each contain
two integrated Hall transducers (E1 and E2) that are used
to sense a magnetic field differential across the face of the
IC (see Sensor Location drawing). Referring to Figure 1,
the trigger switches the output ON (output LOW) when
B
E1
- B
E2
< B
OP
and switches the output OFF (output
HIGH) when B
E1
- B
E2
< B
RP
. The difference between B
OP
and B
RP
is the hysteresis of the device.
Figure 2 relates the output state of a back-biased
sensor IC, with switching characteristics shown in Figure
1, to the target gear profile and position. Assume a north
pole back-bias configuration (equivalent to a south pole at
the face of the device). The motion of the gear produces
a phase-shifted field at E1 and E2 (Figure 2(a)); internal
conditioning circuitry subtracts the fields at the two
elements (Figure 2(b)); this differential field is band-pass
filtered to remove dc offset components and then fed into
a Schmitt trigger; the Schmitt trigger switches the output
transistor at the thresholds B
OP
and B
RP
. As shown
(Figure 2(c)), the IC output is LOW whenever sensor E1
sees a (ferrous) gear tooth and sensor E2 faces air. The
output is HIGH when sensor E1 sees air and sensor E2
sees the ferrous target.
AC-Coupled Operation.
Steady-state magnet and
system offsets are eliminated using an on-chip differential
band-pass filter. The lower frequency cut-off of this
patented filter is set using an external capacitor the value
of which can range from 0.01
µF
to 10
µF.
The high-
frequency cut-off of this filter is set at 30 kHz by an
internal integrated capacitor.
The differential structure of this filter enables the IC to
reject single-ended noise on the ground or supply line
and, hence, makes it resistant to radio-frequency and
electromagnetic interference typically seen in hostile
remote sensing environments. This filter configuration
also increases system tolerance to capacitor degradation
at high temperatures, allowing the use of an inexpensive
external ceramic capacitor.
24 V
MAX
OUTPUT VOLTAGE IN VOLTS
B
OP
B
RP
0
-B
V
OUT(SAT)
0
DIFFERENTIAL FLUX DENSITY, B
E1
– B
E2
+B
Dwg. GH-034
Figure 2
LEADING
EDGE
TRAILING
EDGE
GEAR
DIRECTION
OF ROTATION
E2
E1
NORTH
SOUTH
4300 G
B &B
E1
E2
(a)
4130 G
150 G
B
OP
(b)
B –B
E1
E2
0G
B
RP
-150 G
V
OUT
(c)
V
OUT(SAT)
OUTPUT DUTY CYCLE
≈
50%
Dwg. WH-003-1
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