The A1266 integrated circuit is an ultrasensitive Hall-effect
switch with 3D omnipolar magnetic actuation. The single
silicon chip includes: three Hall plates, multiplexer, small-
signal amplifier, chopper stabilization, Schmitt trigger, and
NMOS output transistors. The device outputs turn on when a
magnetic field of sufficient strength is applied to the sensor
in any orientation. Removal of the magnetic field will turn
the output off.
Two versions of the A1266 offer a choice of output format:
separate X, Y, and Z outputs, or a combined X+Y+Z output.
The low operating supply voltage, 2.5 to 5.5 V, and unique
clocking algorithm assist in reducing the average power
consumption, making it ideal for battery operation (e.g., the
power consumption is less than 25 μW with a 3.3 V supply).
The small geometries of the BiCMOS process allow for
ultrasmall packages suitable for even space-constrained
applications. In this case, a modified SOT23-W surface-mount
package is available in a 3-pin (combined output) or a 5-pin
(separate outputs) configuration, magnetically optimized for
use in a variety of orientations. The packages are lead (Pb) free
and RoHS-compliant, with 100% matte-tin leadframe plating.
A1266-DS, Rev. 4
• True 3D sensing
• Omnipolar operation with either north or south pole
• 2.5 to 5.5 V operation
• Low supply current
• High sensitivity, B
OP
typically 25 G
• Chopper-stabilized offset cancellation
□ Superior temperature stability
□ Extremely low switchpoint drift
□ Insensitive to physical stress
• Solid-state reliability
• Choice of output format
□ Separate X, Y, and Z outputs
□ Combined (X+Y+Z) output
• Tiny SOT-23 packages
Micropower Ultrasensitive 3D Hall-Effect Switch
PACKAGES:
Functional Block Diagram
Not to scale
A1266
VDD
X Hall
YHall
Z Hall
Hall
Amp.
Dynamic Of
fset
Cancellation
Low-Pass
Filter
To All Subcircuits
Sample, Hold &
Averaging
Demultiplexer
Output
Logic
GND
OUTX (OUT
OUTY (n/a)
OUTZ (n/a)
Note for Pin Designations: Triple-Output (Single Output) Options
FEATURES AND BENEFITS DESCRIPTION
5-Pin SOT23-W 3-Pin SOT23-W
April 10, 2017
