ATS617LSG Datasheet, PDF (1/16 Pages) Allegro MicroSystems – Dynamic, Self-Calibrating, Peak-Detecting, Differential Hall Effect Gear Tooth Sensor IC

ATS617LSG
Dynamic, Self-Calibrating, Peak-Detecting, Differential
Hall Effect Gear Tooth Sensor IC
Features and Benefits
▪ Self-calibrating for tight timing accuracy
▪ First-tooth detection
▪ Immunity to air gap variation and system offsets
▪ Immunity to signature tooth offsets
▪ Integrated capacitor provides analog peak and
valley information
▪ Low timing-accuracy drift with temperature changes
▪ Low radiated emissions
▪ Integrated, series resistor on VCC pin for improved
transient immunity
▪ Large air gap capability
▪ Small, integrated package
▪ Optimized magnetic circuit
▪ Undervoltage lockout (UVLO)
▪ Wide operating voltage range
Package: 4-pin SIP (suffix SG)
Not to scale
Description
The ATS617 gear-tooth sensor IC is a peak-detecting device
that uses automatic gain control and an integrated capacitor
to provide extremely accurate gear edge detection down to
low operating speeds. Each device consists of a high-tem-
perature plastic shell that holds together a samarium-cobalt
pellet, a pole piece, and a differential open-collector Hall IC
that has been optimized to the magnetic circuit. This small
package can be easily assembled and used in conjunction
with a wide variety of gear shapes and sizes.
The technology used for this device is Hall-effect based. The
device incorporates a dual-element Hall IC that switches in
response to differential magnetic signals created by fer-
romagnetic targets. The sophisticated processing circuitry
contains an A-to-D converter that self-calibrates (normal-
izes) the internal gain of the device to minimize the effect of
air gap variations. The patented peak-detecting filter circuit
provides immunity to magnet and system offsets and has the
ability to discriminate relatively fast changes such as those
caused by tilt, gear wobble, and eccentricities. This easy-to-
integrate solution provides first falling edge detection and
stable operation to extremely low rpm. The ATS617 can be
used as a replacement for the ATS616.
The ATS617 is ideal for use in systems that gather speed,
position, and timing information using gear-tooth-based
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Functional Block Diagram
VCC
Hall
Amp
Hall
Amp
RS
Voltage
Regulator
UVLO
Gain
Reference
Generator
Power-On
Logic
Tooth and Valley
Comparator
Track and
Hold
Current
Limit
Track and
Hold
VOUT
ATS617LSG-DS, Rev. 1
GND
(Recommended)
TEST