Allegro MicroSystems, Inc. Site MapContact Us
中文English
High-Performance Power and Hall-Effect Sensor ICs

A1225, A1227, and A1229
Hall Effect Latch for High Temperature Operation

Pin-Out or Package

Features and Benefits

  • Symmetrical switchpoints
  • Superior temperature stability
  • Operation from unregulated supply
  • Open-drain 25 mA output
  • Reverse Battery protection
  • Activate with small, commercially available permanent magnets
  • Solid-state reliability
  • Small size
  • Resistant to physical stress
  • Enhanced ESD structures result in 8 kV HBM ESD performance without external protection components
  • Internal protection circuits enable 40 V load dump compliance without external protection components

Description

These Hall-effect latches are extremely temperature-stable and stress resistant sensor ICs especially suited for operation over extended temperature ranges to 150°C. Superior hightemperature performance is made possible through a novel Schmitt trigger circuit that maintains operate and release point symmetry by compensating for temperature changes in the Hall element. Additionally, internal compensation provides magnetic switchpoints that become more sensitive with temperature, hence offsetting the usual degradation of the magnetic field with temperature. The symmetry capability makes these devices ideal for use in pulse-counting applications where duty cycle is an important parameter. The three basic devices (A1225, A1227, and A1229) are identical except for magnetic switchpoints.

Each device includes on a single silicon chip a voltage regulator, Hall-voltage generator, temperature compensation circuit, signal amplifier, Schmitt trigger, and a buffered open-drain output to sink up to 25 mA. The on-board regulator permits operation with supply voltages of 3.8 to 24 V.

The first character of the part number suffix determines the device operating temperature range. Suffix L is for –40°C to 150°C. Two package styles provide a magnetically optimized package for most applications. Suffix LT is a miniature SOT89/TO-243AA transistor package for surface-mount applications, suffix UA is a three-lead ultra-mini-SIP. Both packages are lead (Pb) free with 100% matte tin leadframe plating.

Functional Block Diagram

Functional Block Diagram

Complete Part Numbers
Part Number Package Type RoHS
Compliant
Part Composition/
RoHS Data
Temperature Comments Samples Distributor Stock
A1225LLTTR-T 3-lead SOT Yes view data -40 °C to  150 °C new   Contact Local Sales Representative
or check distributor stock
A1225LUA-T 3-pin SIP Yes view data -40 °C to  150 °C new   Contact Local Sales Representative
or check distributor stock
A1227LLTTR-T 3-lead SOT Yes view data -40 °C to  150 °C new   Contact Local Sales Representative
or check distributor stock
A1227LUA-T 3-pin SIP Yes view data -40 °C to  150 °C new   Contact Local Sales Representative
or check distributor stock
A1229LLTTR-T 3-lead SOT Yes view data -40 °C to  150 °C new   Contact Local Sales Representative
or check distributor stock
A1229LUA-T 3-pin SIP Yes view data -40 °C to  150 °C new   Contact Local Sales Representative
or check distributor stock

Allegro's products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system.

Copyright © 2010 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Worcester, MA 01606 USA Phone: 1.508.853.5000 Fax: 1.508.853.7895