A3211 and A3212
Micropower, Ultrasensitive
Hall-Effect Switches
FEATURES AND BENEFITS
DESCRIPTION
•
•
•
•
•
The A3211 and A3212 integrated circuits are ultrasensitive, pole
independent Hall-effect switches with latched digital output.
These devices are especially suited for operation in batteryoperated, hand-held equipment such as cellular and cordless
telephones, pagers, and palmtop computers. A 2.5 to 3.5
V
operation and a unique clocking scheme reduce the average
operating power requirements to less than 15 μW with a
2.75 V supply.
•
•
•
•
AEC-Q100 automotive qualified
Micropower operation
Operation with north or south pole
2.5 to 3.5 V battery operation
Chopper stabilized
□□ Superior temperature stability
□□ Extremely low switchpoint drift
□□ Insensitive to physical stress
High ESD protection
Solid-state reliability
Small size
Easily manufacturable with magnet pole independence
PACKAGES:
Unlike other Hall-effect switches, either a north or south pole
of sufficient strength will turn the output on in the A3212,
and in the absence of a magnetic field, the output is off. The
A3211 provides an inverted output. The polarity independence
and minimal power requirements allow these devices to easily
replace reed switches for superior reliability and ease of
manufacturing, while eliminating the requirement for signal
conditioning.
DFN (EL)
Improved stability is made possible through chopper
stabilization (dynamic offset cancellation), which reduces the
residual offset voltage normally caused by device overmolding,
temperature dependencies, and thermal stress.
DFN (EH)
This device includes on a single silicon chip a Hall-voltage
generator, small-signal amplifier, chopper stabilization, a
latch, and a MOSFET output. Advanced CMOS processing
is used to take advantage of low-voltage and low-power
SIP (UA)
SOT23W (LH)
Continued on next page....
Not to scale
SUPPLY
SWITCH
LATCH
OUTPUT
SAMPLE
& HOLD
X
DYNAMIC
OFFSET CANCELLATION
TIMING
LOGIC
GROUND
Dwg. FH-020-5
Functional Block Diagram
3211-DS, Rev. 24
February 27, 2017
