A1162 Datasheet, PDF (1/23 Pages) Allegro MicroSystems – Programmable Precision Hall-Effect Switch with Advanced Diagnostics

A1162
Programmable Precision Hall-Effect
Switch with Advanced Diagnostics
FEATURES AND BENEFITS
• User-programmable unipolar switchpoints
• Integrated diagnostics for enhanced system safety and
reliability
□□Enabled on demand
□□Integrated electromagnetic coils test the entire sensor
signal path
□□Designed for ISO 26262 / ASIL systems (QM)
• Chopper stabilized
□□Resistant to physical stress
□□Superior temperature stability
• Internal regulator for wide operating voltage range
□□3.8 to 24 V
• Automotive-grade ruggedness
□□Solid-state reliability
□□Reverse-battery protection
□□Output short-circuit protection
□□AEC-Q100 qualified
2
-
• Small surface-mount package
PACKAGE:
8-Pin eTSSOP (Suffix LE)
Not to scale
DESCRIPTION
The A1162 is a unipolar Hall-effect switch with an externally
enabled diagnostic function and user-programmable
switchpoints. On-chip electromagnetic coils are used to
implement self-test of the sensor’s entire magnetic and electrical
signal chain. It is designed for systems where precise magnet
switchpoints and safety, reliability, or both, are critical, such
as those designed to meet the requirements of ISO 26262.
In normal operating mode, the A1162 functions as a standard
unipolar Hall-effect switch. The device output transistor turns
on (output signal switches low) in the presence of sufficient
magnetic field (>B_OP max). The output transistor of the A1162
switches off (output signal switches high) when the magnetic
field is removed (<B_RP min).
When the diagnostic feature is enabled, the output of the A1162
provides a square wave output which confirms the device
is properly sensing the internally generated magnetic field.
Therefore, use of the A1162 either eliminates the need for
redundant sensors in safety-critical applications or increases
robustness in safety-critical applications that might otherwise
require redundant sensors (drive-by-wire systems, etc.).
This monolithic IC integrates a voltage regulator, Hall voltage
generator, small-signal amplifier, chopper stabilization, Schmitt
trigger, and short-circuit-protected open-collector output able
to sink up to 25 mA. The on-board regulator permits operation
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V_CC
DIAG
A1162-DS
V_REG
Regulator
To all subcircuits
AMP
Trim Control
Switchpoint
Programming
Signal
Recovery
Control
V_REG
Threshold
NORM
DAIG
Current
Limit
System Diagnostics
V_OUT
Functional Block Diagram
GND