ATS657 Datasheet, PDF (1/15 Pages) Allegro MicroSystems – The ATS657 includes an optimized Hall-effect sensing integrated circuit (IC) and rare earth pellet to create a user..

ATS657
Dynamic, Self-Calibrating, Threshold-Detecting, Differential
Speed and Direction Hall-Effect Gear Tooth Sensor IC
Features and Benefits
▪ Rotational direction detection
▪ High start-up and running mode vibration immunity
▪ Single-chip sensing IC for high reliability
▪ Internal current regulator for two-wire operation
▪ Variable pulse width output protocol
▪ Automatic Gain Control (AGC) and offset adjust circuit
▪ True zero-speed operation
▪ Wide operating voltage range
▪ Undervoltage lockout
▪ ESD and reverse polarity protection
Package: 4-pin SIP (suffix SH)
Not to scale
Description
The ATS657 includes an optimized Hall-effect sensing
integrated circuit (IC) and rare earth pellet to create a user-
friendly solution for direction detection and true zero-speed,
digital gear tooth sensing in two-wire applications. The small
package can be easily assembled and used in conjunction with
a wide variety of gear tooth sensing applications.
The IC employs patented algorithms for the special operational
requirements of automotive transmission applications.
The speed and direction of the target are communicated by
this two-wire device through a variable pulse width output
protocol. The advanced vibration detection algorithm
systematically calibrates the IC on the initial teeth of a true
rotation signal and not on vibration, always guaranteeing
an accurate signal in running mode. Even the high angular
vibration caused by engine cranking is completely rejected
by the device.
Patented running mode algorithms also protect against air
gap changes whether or not the target is in motion. Advanced
signal processing and innovative algorithms make the ATS657
an ideal solution for a wide range of speed and direction
sensing needs.
The device package is lead (Pb) free, with 100% matte tin
leadframe plating.
Functional Block Diagram
VCC
Offset
Adjust
Offset
Adjust
AGC
AGC
Peak
Detection
Logic
Internal
Regulator
PDAC
NDAC
PDAC
NDAC
THRESHP
Reference
Generator
and Update
THRESHN
THRESHP
Reference
Generator
and Update
THRESHN
ATS657-DS, Rev. 3
＋
–
Threshold
Logic
–
＋
Speed and
Output
Direction
Protocol
Logic
Control
＋
–
Threshold
Logic
–
＋
GND