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 theATS657

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.

ATS657-DS, Rev. 3

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

Dynamic, Self-Calibrating, Threshold-Detecting, Differential

Speed and Direction Hall-Effect Gear Tooth Sensor IC

Package: 4-pin SIP (suffix SH)

Functional Block Diagram

Not to scale

ATS657

Internal

Regulator

VCC

Offset

Adjust

PDAC

NDAC

THRESHP

Reference

Generator

and Update

THRESHN

Offset

Adjust

PDAC

NDAC

THRESHP

Reference

Generator

THRESHN

AGC

AGC

＋

–

＋

Threshold

Logic

＋

＋

Threshold

Logic

Speed and

Direction

Logic

Peak

Detection

Logic

Output

Protocol

Control

and Update

–

–

–

GND