These Hall-effect latches are extremely temperature-stable and stress-resistant sensors especially suited for operation over extended temperature ranges to +150°C. Superior high-temperature 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 switch points 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 four basic devices (3185, 3187, 3188, and 3189) are identical except for magnetic switch points. Each device includes on a single silicon chip a voltage regulator, quadratic Hall-voltage generator, temperature compensation circuit, signal amplifier, Schmitt trigger, and a buffered open-collector output to sink up to 25 mA. The on-board regulator permits operation with supply voltages of 3.8 to 24 volts. The first character of the part number suffix determines the device operating temperature range. Suffix ‘E–’ is for -40°C to +85°C, and suffix ‘L–’ is for -40°C to +150°C. Three package styles provide a magnetically optimized package for most applications. Suffix ‘–LT’ is a miniature SOT89/ TO-243AA transistor package for surface-mount
This document provides technical specifications for the Allegro MicroSystems A3185, A3187, A3188, and A3189 Hall-effect latch series. These devices are designed for high-temperature operation up to +150°C and feature symmetrical operate and release points maintained by a novel Schmitt trigger circuit.
| Continuous Output Current | 25 mA |
|---|---|
| Operating Temperature Range (Suffix L) | -40°C to +150°C |
| Storage Temperature Range | -65°C to +170°C |
The first character of the part number suffix indicates the range, where 'E-' is for -40°C to +85°C and 'L-' is for -40°C to +150°C.
The series includes devices 3185, 3187, 3188, and 3189, which are identical except for their magnetic switch points.