ATS617 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-temperature
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
ferromagnetic targets. The sophisticated processing circuitry
contains an A-to-D converter that self-calibrates (normalizes)
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