ATS675LSE Datasheet, PDF (1/13 Pages) Allegro MicroSystems – Self-Calibrating TPOS Speed Sensor Optimized for Automotive Cam Sensing Applications

ATS675LSE
Self-Calibrating TPOS Speed Sensor
Optimized for Automotive Cam Sensing Applications
Features and Benefits
▪ Chopper stabilized; optimized for automotive cam
sensing applications
▪ Optimized absolute timing accuracy step size through
gradual transition from TPOS to Running Mode
▪ High immunity to signal anomalies resulting from
magnetic overshoot and peak-to-peak field variation
▪ Tight timing accuracy over full operating
temperature range
▪ True zero-speed operation
▪ Automatic Gain Control circuitry for air gap
independent switchpoints
▪ Operation at supply voltages down to 3.3 V
▪ Digital output representing target profile
▪ Undervoltage lockout (UVLO)
▪ Patented Hall IC-magnet system
▪ Increased output fall time for improved radiated
emissions performance
Package: 4-pin SIP module (suffix SE)
Not to scale
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Description
The ATS675 is the next generation of the Allegro^® True
Power-On State (TPOS) sensor family, offering improved
accuracy compared to prior generations, gradual TPOS to
Running Mode adjustment for accuracy-shift reduction,
and longer output fall time for improved radiated emissions
performance. The ATS675 provides absolute zero-speed
performance and TPOS information.
The sensor incorporates a single-element Hall IC with an
optimized custom magnetic circuit that switches in response
to magnetic signals created by a ferromagnetic target. The IC
contains a sophisticated digital circuit designed to eliminate
the detrimental effects of magnet and system offsets. Signal
processing is used to provide device performance at zero target
speed, independent of air gap, and which adapts dynamically
to the typical operating conditions found in automotive
applications, particularly camshaft-sensing applications.
High resolution peak-detecting DACs are used to set the adaptive
switching thresholds of the device, ensuring high accuracy
despite target eccentricity. Internal hysteresis in the thresholds
reduces the negative effects of anomalies in the magnetic signal
(such as magnetic overshoot) associated with targets used in
many automotive applications. The resulting output of the
device is a digital representation of the ferromagnetic target
profile. The ATS675 also includes a low bandwidth filter that
increases the noise immunity and the signal-to-noise ratio of
the sensor.
The device package is lead (Pb) free, with 100% matte tin
leadframe plating.
Typical Application
V_S
C_BYPASS
0.1 μF
1
VCC
ATS675
3
2
TEST
OUT
A
GND
4
A Recommended
V_PU
R_PU
Sensor
Output
C_L
ATS675LSE-DS
Figure 1. Operational circuit for the ATS675