This next generation family of unipolar switches is intended to refresh Allegro’s successful family of chopper stabilized switches that have been in production for almost 10 years. The A1121 and A1122 are intended to replace the A3241 and A3242 respectively. Although the new devices will be identical to their predecessors with respect to magnetic switching points, there are significant performance and feature upgrades. Foremost, the devices will be able to survive an ESD event up to 3kV in the Human Body Model. Second, they are capable of handling a much lower minimum Vcc, which allows use of higher series resistance for protection, when the available supply voltage is below 5V. Third, a new high speed chopping circuit is employed to null out offsets and dramatically improve repeatability. And finally, they have significantly reduced settling times, allowing faster response to changing magnetic fields.

The A112x series thus provide extremely temperature-stable switch points and operate over a wider voltage range. They are suited for temperature operating ranges from -40° to +150°C.