A1242LUA-I2-T Equivalent & Substitute Parts

Part Overview

The A1242LUA-I2-T is a digital switch latch Hall Effect magnetic sensor manufactured by Allegro MicroSystems, housed in a 3-SIP through-hole package. This component functions as an open collector magnetic switch with south pole polarization, designed for applications requiring latching behavior in response to magnetic field detection. The part is currently obsolete, making identification of compatible substitutes essential for ongoing system support and new design implementations.

Substiute Parts

A1242LUA-I2-T

Allegro MicroSystemsIn Stock: 1029A1242LUA-I2-T Datasheet

Current PartRFQ

A1244LUA-I2-T

Allegro MicroSystemsIn Stock: 1054A1244LUA-I2-T Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The A1244LUA-I2-T qualifies as a direct substitute for the A1242LUA-I2-T based on the following alignment of critical parameters:

Matching Parameters:

• Hall Effect technology with south pole polarization
• Identical sensing range (8mT trip, -8mT release)
• Identical latching function
• Identical operating temperature range (-40°C ~ 150°C)
• Identical supply current specification (5mA maximum)
• Identical through-hole mounting in 3-SSIP package
• ROHS3 compliance maintained

Allowable Variation:

• Supply voltage range: A1244LUA-I2-T operates at 3V ~ 24V versus A1242LUA-I2-T at 4.6V ~ 24V. The A1244LUA-I2-T supports a lower minimum voltage threshold, making it compatible with the original specification range.
• Output type: A1244LUA-I2-T uses open drain versus A1242LUA-I2-T open collector. Both are functionally equivalent switching topologies for this application class.

Product Status Advantage: The A1244LUA-I2-T is active production status with AEC-Q100 automotive qualification, providing long-term availability and supply chain stability compared to the obsolete A1242LUA-I2-T.

Parameter Comparison

Engineering Selection Recommendations

The A1244LUA-I2-T is the appropriate substitute for the obsolete A1242LUA-I2-T. Selection is justified on the following engineering basis:

Functional Equivalence: Both components share identical Hall Effect sensing technology, latching behavior, magnetic threshold specifications, and thermal operating range. The sensing range of 8mT trip and -8mT release is preserved, ensuring equivalent magnetic field response characteristics.

Electrical Compatibility: The A1244LUA-I2-T supply voltage range of 3V ~ 24V encompasses the original 4.6V ~ 24V specification. Maximum supply current remains at 5mA. Open drain output topology is functionally equivalent to open collector for standard switching applications and maintains compatibility with typical pull-up resistor configurations.

Package and Mounting Compatibility: Both components use identical 3-SSIP through-hole packaging, enabling direct PCB footprint compatibility without layout modifications.

Compliance and Availability: The A1244LUA-I2-T maintains ROHS3 compliance and adds AEC-Q100 automotive qualification, providing enhanced reliability documentation and active production status. This ensures long-term component availability and supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Can the A1244LUA-I2-T directly replace the A1242LUA-I2-T without circuit modifications?

A: Yes. Both components share identical package geometry (3-SSIP), pinout, sensing thresholds, and operating temperature range. The open drain output of the A1244LUA-I2-T is functionally equivalent to the open collector output in standard switching circuits. No PCB layout or pull-up resistor modifications are required.

Q: What is the difference between open collector and open drain outputs?

A: Both topologies function as switches that pull an output line to ground when activated. Open collector uses a bipolar transistor; open drain uses a field-effect transistor. For this magnetic sensor application, both provide equivalent switching behavior and are compatible with standard pull-up resistor networks.

Q: Does the lower minimum supply voltage of the A1244LUA-I2-T (3V vs. 4.6V) affect compatibility?

A: No. The A1244LUA-I2-T supports operation down to 3V, which is lower than the original 4.6V minimum. This represents an expanded operating range and maintains full compatibility with systems designed for the 4.6V ~ 24V specification.

Q: Are there any thermal or magnetic performance differences between these parts?

A: No. Both components operate across the identical temperature range (-40°C ~ 150°C) and share the same magnetic sensing thresholds (8mT trip, -8mT release). Performance characteristics are equivalent.

Q: Why is the A1244LUA-I2-T preferred over the obsolete A1242LUA-I2-T?

A: The A1244LUA-I2-T is in active production with AEC-Q100 automotive qualification, ensuring long-term availability and supply chain stability. The obsolete status of the A1242LUA-I2-T creates sourcing risk for new designs and ongoing system support.