Micropower hall switches raise detection circuit performance

15th October 2013

Nat Bowers

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Diodes Incorprated has today announced an extension of its Hall effect switches family with the introduction of the AH1902 and AH1903 high sensitivity, micropower devices. Offering greater design flexibility as well as power and space savings, the new Hall effect switches help raise the performance of a wide range of contact-less switch applications in consumer, domestic, office and industrial products.

The AH1902 is an omnipolar device, detecting both north and south pole magnets. In default mode, the programmable AH1903 operates as a unipolar device, detecting a south pole at the part marked package surface. The device also offers an omnipolar mode, enabling it to meet the needs of multiple applications and to be changed ‘on the fly’ in the event of a field direction issue. The AH1903 function is changed via a simple select pin, driven by an external logic source or microcontroller.

The high sensitivity of both switches means weaker magnets can be employed or detection distances extended; the switches’ typical operating threshold switch point being ±35G.

To aid product miniaturization, the switches are provided in a choice of space-saving low profile surface mount packages. The omnipolar AH1902 comes in the DFN1216-4, ultra-thin DFN2015-6 and SOT553 packages. And in the 1.2x1.6x0.5mm DFN1216-4 package, the AH1903 is the industry’s smallest omnipolar/unipolar programmable Hall switch.

To accommodate a wide range of hand-held applications, these high-reliability switches have an 8kV electrostatic discharge withstand capability and offer good immunity to RF noise and other circuit stresses. Operating and release points are also highly stable over the temperature range -40ºC to +85ºC, and with a very low temperature coefficient, the switches are immune to early or late switching.

Designed to be used with a low voltage supply, these latest Hall switches from Diodes will operate over the range 1.6V to 3.6V. This factor, coupled with an integral sleep function and a typical current consumption figure of 4.3µA, makes them a good performer in battery-powered applications.

In 10k quantities, the AH1902 omnipolar Hall effect switch is priced at $0.18USD each and the AH1903 omnipolar/unipolar programmable Hall effect switch at $0.185USD each.