ATS651LSH

651LSH-DS, Rev. 3

Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

ABSOLUTE MAXIMUM RATINGS

Temperatures

*Refer to Power Derating section

Two-Wire Self-Calibrating Differential

Speed and Direction Sensor with Vibration Immunity

Use the following complete part numbers when ordering:

Package SH

Features and Benefits

1. VCC

2. TESTA pin, Channel A

3. TESTB pin, Channel B

4. GND

1 2

3 4

The ATS651LSH is a mechatronics component with an integrated Hall-effect

sensor and magnet, providing an easy-to-use solution for speed and direction sens-

ing applications. The solid thermoset molded plastic package contains a samarium

cobalt magnet and a Hall-effect IC optimized to the magnetic circuit. This sensor

module has been designed specifically for high reliability in the harsh automo-

tive environment. The IC employs patented algorithms for the special operational

requirements of transmission applications.

This two-wire device communicates the speed and direction of a ferrous target

via a pulse width modulation (PWM) output protocol. The innovative dual differ-

ential detector scheme uses three Hall elements and two separate signal processing

channels. This provides greater reliability than conventional designs. Because only

one of the channels controls switching, the same edge of each tooth is used for

determining output signals, in both forward and reverse target rotation, with direc-

tion information available on the first magnetic edge after a direction change.

The ATS651LSH is particularly adept at handling vibration without sacrific-

ing maximum air gap capability or creating an erroneous “direction” pulse. Even

the higher angular vibration caused by engine cranking is completely rejected by

the device. The advanced vibration detection algorithms systematically calibrate

the sensor on the true rotation signals from the first three and a half teeth, not on

vibration, thus always guaranteeing an accurate signal in running mode.

Patented running mode algorithms also protect against air gap changes, whether

or not the target is in motion. Advanced signal processing and innovative algo-

rithms make the ATS651LSH an ideal solution for a wide range of speed and

direction sensing needs.

The device package is lead (Pb) free, with 100% matte tin plated leadframe.

Part Number

Packing*

ATS651LSHTN-T

13-in. reel, 800 pieces/reel

*Contact Allegro for additional packing options.

• Rotational direction detection

• Fully optimized digital differential gear-tooth sensor

• Single-chip sensing IC for high reliability

• Small mechanical size (8 mm diameter × 5.5 mm vertical, flat-to-flat)

• Internal current regulator for 2-wire operation

• Automatic Gain Control (AGC) and reference adjust circuit

• 3-bit factory trimmed for tight pulse width accuracy

• True zero-speed operation

• Wide operating voltage range

• Undervoltage lockout

• Defined power-on state

• ESD and reverse polarity protection

Some restrictions may apply to certain types of sales.

Contact Allegro for details.