Fea tures
Designed for use as gear tooth sensor
Reverse battery protection
Zero speed sensing
-40
o
C to +150
o
C operating
temperature
4.5 to 24 volts supply range
De scrip tion
The OHN3056 & OHS3056 contains a
monolithic integrated circuit which
incorporates a pair of Hall sensing elements,
linear signal amplifiers, and a hysteresis
threshold detector on a single silicon chip.
The chip also includes a bandgap voltage
regulator and temperature compensation
circuitry to provide a stable operation over a
wide range of temperatures and supply
voltages. The device has an open collector
logic output with 20 mA sink current capability
and has an optional on chip pull-up resistor.
The device has two Hall elements spaced
0.088 inches (2.24 millimeters) apart. The
Hall elements are connected to two separate
linear amplifiers whose outputs are connected
to a third differential amplifier. The output of
the differential amplifier represents only the
difference in magnetic flux density between
the two Hall elements. The output of the
differential amplifier is coupled to the
threshold detector, and when the difference in
the magnetic flux density exceeds the
threshold, the logic output changes states.
The device is designed for use as a single
sided gear tooth sensor. By placing a bias
magnet behind the device and passing a
ferrous metal target over the package surface,
Ab so lute Maxi mum Rat ings (T
A
= 25
o
C un less oth er wise noted)
Sup ply Volt age, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 V
Stor age Tem pera ture Range, T
S
. . . . . . . . . . . . . . . . . . . . . . . . . . . -65
o
C to +160
o
C
Op er at ing Tem pera ture Range, T
A
OHS3056 . . . . . . . . . . . . . . . . . -40
o
C to +150
o
C
Op er at ing Tem pera ture Range, T
A
OHN3056 . . . . . . . . . . . . . . . . . . -20
o
C to +85
o
C
Lead Sol der ing Tem pera ture (1/8 inch [3.2 mm] from case for 5 sec. with sol der ing
iron) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
o
C
(1)
Out put ON Cur rent, I
SINK
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 mA
Out put OFF Volt age, V
OUT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 V
Mag netic Flux Den sity, B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Un lim ited
Re verse Bat tery Volt age, V
RCC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 V
Notes:
(1) Heat sink leads during hand soldering.
Func tional Block Dia gram
Prod uct Bul le tin OHN3056, OHS3056
PRE LIMI NARY
March 1996
Hal logic
Dif fer en tial Mag netic Sen sors
Types OHN3056, OHS3056
Op tek Tech nol ogy, Inc. 1215 W. Crosby Road Car roll ton, Texas 75006 (972) 323- 2200 Fax (972) 323- 2396
10-22
Types OHN3056, OHS3056 PRELIMINARY
Op tek re serves the right to make changes at any time in or der to im prove de sign and to sup ply the best prod uct pos si ble
Op tek Tech nol ogy, Inc. 1215 W. Crosby Road Car roll ton, Texas 75006 (972)323- 2200 Fax (972)323- 2396
Elec tri cal Char ac ter is tics (V
CC
= 4.5 to 24 V)
SYM BOL
PA RAME TER
MIN TYP MAX UNITS
TEST CON DI TIONS
B
OP
Magnetic Operate Point
(4)
, B
A
(2)
-B
B
(3)
150
Gauss T
A
= 25
o
C
B
RP
Magnetic Release Point, B
A
(2)
-B
B
(3)
-150
Gauss T
A
= 25
o
C
B
H
Magnetic Hysteresis,
B
OP
-
B
OP
50
Gauss TA = 25
o
C
I
CC
Supply Current
10.0
mA
V
CC
= 24 V, Output Off,
B
-150 Gauss
V
OL
Output Saturation Voltage
160
400
mV
V
CC
= 4.5 V, I
OL
= 20 mA,
B
150
Gauss
I
OH
Output Leakage Current
0.1
5.0
A
V
CC
= 24 V, V
OUT
= 24 V,
B
-150 Gauss
t
r
Output Rise Time
0.05
1.00
s
R
L
= 820
, C
L
= 20 pF, V
CC
= 14 V
t
f
Output Fall Time
0.12
1.00
s
Notes:
2) B
A
is the magnetic flux density at Hall Element A.
3) B
B
is the magnetic flux density at Hall Element B.
4) South pole facing symbolized surface.
10-23
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