[Allegro]

Description
The A1171 integrated circuit is an ultrasensitive, Hall effect switch with latched digital outputs and either unipolar or omnipolar magnetic actuation. It features operation at low supply currents and voltages, making it ideal for battery operated electronics. The low operating supply voltage, 1.65 to 3.5 V, and unique clocking algorithm assist in reducing the average operating power consumption. For example, the power requirement is less than 15 μW with a 2.75 V supply.
Unlike more traditional Hall effect switches, the A1171 allows the user to configure how the device is magnetically actuated. Under default conditions the device activates output switching with either a north or south polarity magnetic field of sufficient strength. The magnetic actuation can be set via an external selection pin to operate in a unipolar mode, switching only on a north or south polarity but not both. Furthermore, the output of the A1171 can be configured to switch either off or on in the absence of any significant magnetic field. Lastly, the A1171 has two push-pull output structures.

FEATUREs and Benefits
▪ 1.65 to 3.5 V battery operation
▪ Low supply current
▪ High sensitivity, BOP typically 30 G (3.0 mT)
▪ Operation with either north or south pole
▪ Configurable unipolar or omnipolar magnetic sensing
▪ Complementary, push-pull outputs
▪ Chopper stabilized
   ▫ Superior temperature stability
   ▫ Extremely low switchpoint drift
   ▫ Insensitive to physical stress
▪ Solid state reliability
▪ Small size