ATS674LSETN-LT Allegro Microsystems Inc, ATS674LSETN-LT Datasheet - Page 10

• Manufacturer Part Number: ATS674LSETN-LT
• Description: IC SENSOR GEAR TOOTH 4LEAD
• Manufacturer: Allegro Microsystems Inc
• Type: Special Purposer

Specifications of ATS674LSETN-LT

• Sensing Range: 30% of Air Gap Trip, 40% of Air Gap Release
• Voltage - Supply: 3.3 V ~ 26.5 V
• Current - Supply: 11mA
• Current - Output (max): 20mA
• Output Type: Digital, Open Collector
• Features: Gear Tooth Type
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 4-SIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

ATS673 and
ATS674
Assembly Description
The ATS673 and ATS674 true zero-speed gear tooth sensor
ICs have a Hall IC-rare earth pellet configuration that is fully
optimized to provide digital detection of gear tooth edges. This
device is molded into a plastic body that has been optimized for
size, ease of assembly, and manufacturability. High operating
temperature materials are used in all aspects of construction.
Hall Technology
The devices contain a single-chip Hall effect sensor IC, a 4-pin
leadframe and a specially designed rare-earth pellet. The Hall IC
supports a Hall element that measures the magnetic gradient cre-
ated by the passing of a ferromagnetic object. This is illustrated
Figure 2. Device Cross Section. Motion of the target is detected by the Hall element mounted on the Hall IC. Panel A, the presence of a tooth feature on
the target is distinguished by a high magnetic flux density, B. Panel B, the presence of a valley feature is distinguished by its low magnetic flux density.
Figure 3. The magnetic profile reflects the geometry of the target, allowing the device to present an accurate digital output response.
Back-Biasing
Rare Earth Pellet
High-B field
Plastic
Hall IC
-LT Option
-HT Option
Optimized for Automotive Cam Sensing Applications
Target
Mechanical Profile
Target
Magnetic Profile
IC Output
IC Output
IC Output
IC Output
Switch State
Electrical Profile
Switch State
Electrical Profile
Self-Calibrating TPOS Gear Tooth Sensor ICs
South Pole
North Pole
Operational Description
(A)
V
V
B
OUT
OUT
IN
V+
V+
B
0
On Off On Off On Off On Off
Target (Gear)
Off
ATS Device
in figure 2. The difference in the magnetic gradients created by
teeth and valleys allows the devices to generate a digital output
signal.
Output
After proper power is applied to the devices, they are then
capable of providing digital information that is representative of
the profile of a rotating gear, as illustrated in figure 3. No addi-
tional optimization is needed and minimal processing circuitry is
required. This ease of use reduces design time and incremental
assembly costs for most applications.
On Off On Off On Off On
(B)
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
(Concentrator)
Low-B field
Hall element
Leadframe
Pole piece
9