A1147ELHLT Allegro Microsystems Inc, A1147ELHLT Datasheet - Page 2

• Manufacturer Part Number: A1147ELHLT
• Description: IC SWITCH HALL EFFECT UNI SOT-23
• Manufacturer: Allegro Microsystems Inc
• Type: Unipolar Switchr

Specifications of A1147ELHLT

• Sensing Range: 80G Trip, 10G Release
• Voltage - Supply: 3.5 V ~ 24 V
• Current - Supply: 5mA
• Output Type: Digital, Open Collector
• Features: Regulated Voltage
• Operating Temperature: -40°C ~ 85°C
• Package / Case: SOT-23W
• Magnetic Type: Unipolar
• Operating Supply Voltage (min): 3.5V
• Operating Supply Voltage (typ): 5/9/12/15/18V
• Operating Supply Voltage (max): 24V
• Mag Sensor Operate Point (g): 80Gs
• Mag Sensor Release Point (g): 10Gs
• Mag Sensor Hysteresis(g): 15Gs
• Package Type: SOT-23W
• Pin Count: 3
• Mounting: Surface Mount
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output (max): -
• Lead Free Status / Rohs Status: Not Compliant

Features and Benefits
▪ Chopper stabilization
▪ Factory programmed at end-of-line for optimized
▪ On-chip protection
Packages: 3 pin SOT23W (suffix LH), and
3 pin SIP (suffix UA)
Not to scale
A1147-DS, Rev. 12
switchpoints
▫ Low switchpoint drift over operating
▫ Low sensitivity to stress
▫ Supply transient protection
▫ Reverse-battery protection
▫ On-board voltage regulator
▫ 3.5 to 24 V operation
temperature range
Low Current Ultrasensitive Two-Wire Chopper-Stabilized
V+
0.01 uF
VCC
Functional Block Diagram
Clock/Logic
Amp
Low-Pass
Filter
Regulator
Unipolar Hall Effect Switches
Description
The A1147 and A1148 devices are two-wire, unipolar, Hall
effect switches that are factory-programmed at end-of-line to
optimize ultrasensitive magnetic switchpoint accuracy. These
devices use a patented high frequency chopper-stabilization
technique, produced using the Allegro advanced BiCMOS
wafer fabrication process, to achieve magnetic stability and
to eliminate offset inherent in single-element devices exposed
to harsh application environments.
Commonly found in a number of automotive applications,
these switches are utilized in sensing seat track position, seat
belt buckle presence, hood/trunk latching, and shift selector
position. Two-wire unipolar switches, such as the A1147
and A1148, are particularly advantageous in price-sensitive
applications because they require one less wire for operation
than do switches with the more traditional open-collector output.
Additionally, the system designer inherently gains diagnostics
because there is always output current flowing, which should
be in either of two narrow ranges. Any current level not within
these ranges indicates a fault condition. These devices also
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To All Subcircuits
Package UA Only
GND
A1147 and A1148
GND