ATS665LSG

TRUE ZERO-SPEED GEAR TOOTH SENSOR

Under-Voltage Lockout:

When the supply voltage falls below the minimum operating voltage (Vcc

irrespective of the state of the magnetic field. This prevents false signals caused by under-voltage conditions from

propagating to the output of the sensor.

Power Supply Protection:

The device contains an on-chip regulator and can operate over a wide supply voltage range. For devices that need to

operate from an unregulated power supply, transient protection must be added externally. For applications using a

regulated line, EMI/RFI protection may still be required. The following circuit is the most basic configuration required for

proper device operation. For EMC information, contact your Allegro representative.

Internal Electronics:

The ATS665 contains a self-calibrating Hall effect IC that possesses two Hall elements, a temperature compensated

amplifier and offset cancellation circuitry. The IC also contains a voltage regulator that provides supply noise rejection over

the operating voltage range. The Hall transducers and the electronics are integrated on the same silicon substrate using a

proprietary BiCMOS process. Changes in temperature do not greatly affect this device due to the stable amplifier design

and the offset rejection circuitry.

THRESH

LOGIC

HALL AMP

AUTOMATIC

GAIN

CONTROL

THRESHOLD

COMPARATOR

THRESHP

THRESHN

REFERENCE

GENERATOR

PPEAK

NPEAK

Vsig

PDAC

NDAC

INTERNAL

REGULATOR

Vcc

GND

OUTPUT

Current

Limit

Output

Transisto

r

Final Version, Rev 1.0; DSD; 01Aug03

Page 7

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

Copyright © 1993, 1995 Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036