Two-Wire, Zero Speed
Differential Gear Tooth Sensor IC
ATS685LSH
4
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Functional Characteristics
Operating Signal Range
11
B
SIG
Differential magnetic signal, duty cycle within
specification
50 – 1500 G
PK-PK
Extended Operating Signal Range B
SIGEXT
Differential magnetic signal, output switching (no
missed edges), duty cycle not guaranteed
30 – – G
PK-PK
Operational Air Gap Range AG
OP
Using Allegro Reference Target 60-0, duty cycle
within specification
0.5 – 2.5 mm
Extended Operational Air Gap Range AG
EXT
Using Allegro Reference Target 60-0, output
switching (no missed edges), duty cycle not
guaranteed
– – 3.0 mm
Allowable User-Induced Differential
Offset
B
DIFFEXT
Operation within specification ±60 – – G
Duty Cycle Variation
12
ΔD Wobble < 0.5 mm, AG within specification – – ±10 %
Maximum Sudden Signal Amplitude
Change
B
SIG(INST)
Instantaneous symmetric magnetic signal
amplitude change, measured as a percentage of
peak-to-peak B
SIG
, f
OP
< 500 Hz
–45–%
1
Typical values are at T
A
= 25°C and V
CC
= 12 V. Performance may vary for individual units, within the specified maximum and minimum limits.
2
1 G (gauss) = 0.1 mT (millitesla).
3
Maximum voltage must be adjusted for power dissipation and junction temperature; see Power Derating section.
4
Negative current is defined as conventional current coming out of (sourced from) the specified device terminal.
5
Sustained voltages beyond the clamp voltage may cause permanent damage to the IC.
6
Measured from V
CC
≥ V
CC
(min) to the time when the device is able to switch the output signal in response to a magnetic stimulus.
7
Please refer to the Functional Description, Power-On section.
8
di is the difference between 10% of I
CC(Low)
and 90% of I
CC(High)
. dt is the time period between those two points.
9
C
LOAD
is the probe capacitance of the oscilloscope used to make the measurement.
10
For power-on frequency, f
OP
< 200 Hz. Higher power-on frequencies may result in more input magnetic cycles until full output edge accuracy is
achieved, including the possibility of missed output edges.
11
AG
OP
is dependent on the available magnetic field. The available field is dependent on target geometry and material, and should be independently
characterized. The field available from the reference target is given in the Reference Target table.
12
Target rotation from pin 4 to pin 1.
OPERATING CHARACTERISTICS (continued) V
CC
and T
A
within specification, unless otherwise noted
Characteristics Symbol Test Conditions Min. Typ.
1
Max. Unit
2
