Improved magnetic sensitivity for switch

Edited by the Electronicstalk editorial team Feb 15, 2002

Using CMOS architecture, the latest omnipolar Hall-effect switch, the A3212 from Solid State Supplies, is an ultrasensitive pole-independent Hall-effect switch with a latched digital output.

Using CMOS architecture, the latest omnipolar Hall-effect switch, the A3212 from Solid State Supplies, is an ultrasensitive pole-independent Hall-effect switch with a latched digital output.

An updated and upgraded version of the A3210, and providing improved magnetic sensitivity with minimal switchpoint shifts over temperature, the small package size and low power demands of the A3212 make it a cost effective replacement for switches in all types of portable applications - a common use being lid open detection in laptops, handheld computers, PDAs and mobile telephones.

The polarity independence and minimal power requirements make these devices classic replacements for other types of switch owing to their enduring reliability and ease of manufacturing, while eliminating the requirement for signal conditioning.

A 2.5 to 3.5V battery operation and a unique clocking scheme reduce the average operating power requirements to less than 15uW with a 2.75V supply.

Unlike other Hall-effect switches, either a north or south pole of sufficient strength will turn the output on; in the absence of a magnetic field, the output is off.

Improved stability is made possible through chopper stabilisation (dynamic offset cancellation), which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress.

The A3212 is supplied in a three-lead ultra-mini SIP for through-hole or surface mounting, as well as a three-lead miniature low profile SOT-23 surface mount package.