STATE-OF-THE-ART GMR
GEAR TOOTH SPEED SENSING
50% Larger Air Gap Allows for Optimal System Size and Robustness
Electrified powertrains are all about efficiency. But, the larger
the vehicle, the harder it is to achieve the right balance of motor
size and power for hills and acceleration. An EV transmission can
provide maximum motor power and efficiency, enabling longer
ranges and delivering on performance.

Functional Block Diagram
VCC
GMR
Elements

Ideal for single-speed or two-speed transmissions, Allegro’s
high-performance giant magnetoresistance (GMR) speed anddirection sensor ICs offer a 50% larger air gap, giving installation
flexibility – reducing system size and cost. With inherent stray field
immunity and impressive EMC performance, these are perfect forcompact system designs where EMI and efficiency are concerns.
The ATS19480 and ATS19580 are designed for use in conjunction
with ferromagnetic gear tooth targets and are orientationcompatible with Hall-effect technology. The fully integrated
solutions sense at large operating air gaps and over a large airgap range, increasing placement flexibility for system design
optimization. Optimal system design is vital for reducing systemsize, cost, and weight; perfect for EV applications.
The user-friendly two-wire solutions are ideal for the future oftransmission designs where speed and/or direction information
are required using ferromagnetic gear tooth targets. The newly
introduced ATS19480 provides accurate speed measurement
over a wide operating air gap range that’s 50% greater than its
Hall-effect predecessor. Its counterpart, the ATS19580, provides
robust speed and direction information with industry leading
vibration immunity, also over the increased operating air gap range.
To simplify design-in further, this family of products is offered in a
fully integrated single-in-line package with a monolithic GMR IC,a protection capacitor for EMC robustness, and an optimized
back-bias magnetic circuit.
The state-of-the-art GMR technology on a monolithic IC
incorporates industry-leading signal processing to guarantee+

ADC

Front End
Amplification

Analog-to-DigitalandSignal Conditioning+Digital
Controller

OutputCurrent
Generator

ESD

ADC-Regulator

GND

Oscillator

EEPROM

Diagnostics

accurate response to low-level differential magnetic signals for
reduced controller codes, and prevents flatline conditions in
the presence of system perturbations such as thermal gradients,vibration, and air gap dynamics. The differential sensing offers
inherent rejection of interfering common-mode magnetic fields.
Functional safety is also an essential part of Allegro’s designs.
Integrated diagnostics are used to detect an IC failure that would
impact the output accuracy, providing coverage compatible with
an ASIL B rating. ASIL reporting can be enabled or disabled as aproduct offering depending on the application needs.
Built-in EEPROM scratch memory offers traceability of the device
throughout the IC’s product lifecycle.
The product family is available in the SN package, a lead-free 3-pin
single-in-line package (SIP), that integrates the GMR IC, EMC
capacitor, and magnet in a single overmold for ease of use andadvanced performance. The “SN” has a tin-plated leadframe andan additional molded lead-stabilizing bar for sturdy shipping andease of assembly.

Features and Benefits•

Fully integrated high performance gear tooth sensing,•••

Advanced signal compensation eliminates flatline
conditions due to system dynamicsspeed and/or direction
Single-in-line package contains GMR IC, protection•Orientation compatible with Hall-effect technology

capacitor, and optimized magnet•

Integrated ASIL diagnostics and certified safety design

Increased air gaps allow optimal placement for small,lighter system design

process (with optional fault reporting)Industry Leading Capabilities and Adaptability for the Future in Transmission Design
Setting a New Standard in Transmission Sensor PerformanceWith maximum design flexibility andcutting-edge capabilities, our products
are put to the test to see how we performagainst our competitors. The results?
Allegro’s superiority in algorithm andintegrated package design outperforms
competitive solutions making it the mostreliable and durable solution for yourtransmission applications.

Allegro’s ATS19480 and ATS19580 are redefining gear tooth sensing.
Ideal for the latest spatially optimized transmission designs, these sensors enablesystem weight reductions, increased fuel economy, expanded driving ranges, andhigh-performance speed sensing – especially for electrified vehicles.
ATS19480

ATS19580

2-wire Speed

2-wire Speed and Direction

Large air gap operation, accurate speed measurement
and ASIL rating in a fully integrated package incorporating
the GMR IC, EMC capacitor and magnetic circuit.

Large air gap operation, accurate speed and direction
information, vibration immunity and ASIL rating in a fully
integrated package incorporating the GMR IC,EMC capacitor and magnetic circuit.

Operating Air Gap: 1.5 to 4.5 mm

Performance Starts with Precision Assembly
The “SN” lead-free 3-pin single inline package (SIP) offers precision assembly for optimized IC-to-magnet positioning.
The reduced tolerance stack between the IC and magnet increases sensor accuracy and leaves margin for in-application installation
tolerances.

ALLEGROMICRO.COM

AM016 - 6.21