The ATS643 is an optimized combination of integrated circuit and magnet that
provides a manufacturer-friendly solution for true zero-speed digital gear-tooth
sensing in two-wire applications. The device consists of a single-shot molded
plastic package that includes a samarium cobalt magnet, a pole piece, and a
Hall-effect IC that has been optimized to the magnetic circuit and the automotive
environment. This small package can be easily assembled and used in conjunction
with a wide variety of gear shapes and sizes.
The integrated circuit incorporates a dual element Hall-effect sensor with signal
processing circuitry that switches in response to differential magnetic signals
created by rotating ferrous targets. The device contains a sophisticated compensating circuit to eliminate magnet and system offsets immediately at power-on.
Digital tracking of the analog signal is used to achieve true zero-speed operation,
while also setting the device switchpoints. The resulting switchpoints are air gap
independent, greatly improving output and duty cycle accuracy. The device also
uses a continuous update algorithm to fine-tune the switchpoints while in running
mode, maintaining the device specifications even through large changes in air gap
or temperature.
The regulated current output is configured for two-wire operation, offering inherent diagnostic information. This device is ideal for obtaining speed and duty cycle
information in gear-tooth based applications such as transmission speed sensing.
AB SO LUTE MAX I MUM RAT INGS
Supply Voltage, VCC..................See Power Derating
Reverse-Supply Voltage, V
Operating Temperature
Ambient, T
Maximum Junction, T
Storage Temperature, T
ATS643-DS, Rev. 1
................................ –40ºC to 150ºC
A
........................–18 V
RCC
........................165ºC
J(max)
.................. –65ºC to 170ºC
S
Features and Benefits
• Fully-optimized differential digital gear
tooth sensor
• Single chip-IC for high reliability
• Internal current regulator for 2-wire
operation
• Small mechanical size (8 mm diameter
x 5.5 mm depth)
• Switchpoints air gap independent
• Digital output representing gear profile
Use the following complete part numbers when ordering:
Part NumberPackageICC Typical
ATS643LSH-I14-pin plastic SIP6.0 Low to 14.0 High mA
ATS643LSH-I24-pin plastic SIP7.0 Low to 14.0 High mA
• Precise duty cycle accuracy throughout temperature range