Chopper stabilized all-pole Hall effect switches for industrial, consumer and automotive applications

     In some applications in industrial, consumer and automotive fields, the requirements for operational reliability are increasingly high, especially in some applications with more demanding environmental requirements, which need to be able to withstand adverse factors such as low temperature, moisture, dust and debris. The traditional mechanical switch is not only limited in design and assembly, but also difficult to meet the reliability requirements. The non-contact all-pole Hall switch is an ideal alternative.

     In automotive taillight design, for example, although leds are already very reliable, failure of LED taillights due to effects such as water and debris will be common if conventional switches are used. The seals used to secure the housing and internal protection systems can age and wear over time. When seals fail, contaminants such as water and debris can invade and corrode system components, leading to system failure. Therefore, solutions that can withstand potentially invasive debris and moisture are more reliable. To protect against corrosion and debris failures, Hall Effect switches provide a quiet, non-contact, high reliability solution compared to mechanical switches with limited reliability.

     All-pole Hall effect switch is a digital output latch switch that can operate in strong positive or negative magnetic fields. When installing the magnet, any of its magnetic poles can be oriented towards the all-pole device, thus simplifying application assembly. When the magnet is located in a magnetic field with sufficient flux density, the device will be switched to the on state. After opening, the all-pole device will remain in this state until the magnetic field disappears, at which time the switching device will return to the off state. It locks in the changed state and stays closed until a strong enough magnetic field reappears.

     The A1126 is an all-pole, ultra-sensitive Hall effect switch with a digital output, and its integrated voltage regulator allows operation at up to 24V. The device is particularly suitable for operating in the extended temperature range (-40 ~ 150 ℃). Allegro's patented dynamic offset elimination technology reduces voltage offset caused by overmolding, temperature drift, and thermal molding, protecting the device through extreme temperatures.

     The A1126 integrates patented magnetic-polarity-independence technology, making it an ideal alternative to traditional mechanical reed switches. The A1126 is available in two packages, the SOT23W miniature flat surface mount and the through-hole mounted three-pin subcompact single-insert in-line package. And a single chip integrated voltage regulator, Hall voltage generator, small signal amplifier, chopper stabilizer, Schmitt trigger and short-circuit protection function of open drain output. It uses an advanced BiCMOS wafer fabrication process that offers the advantages of low voltage requirements, component matching, extremely low input offset errors, and small geometry.