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 3.5V, 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, theA1171 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 theA1171 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.

This polarity-independence, as well as the minimal power

requirements,allowstheA1171toeasilyreplacereedswitches,

1171-DS

Features and Benefits

▪ 1.65 to 3.5 V battery operation

▪ Low supply current

▪ 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

Micropower Ultrasensitive Hall Effect Switch

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Package: 6 pin DFN/MLP (suffix EW)

Functional Block Diagram

Not to scale

A1171

VOUTPN

VOUTPS

VDD

Low-Pass

Filter

Clock / Logic

Latch

Latch

Amp

GND

SELECT