A3211 and A3212
Micropower, Ultrasensitive
Hall-Effect Switches
FEATURES AND BENEFITS DESCRIPTION
AEC-Q100 automotive qualified The A3211 and A3212 integrated circuits are ultrasensitive, pole
Micropower operation independent Hall-effect switches with latched digital output.
Operation with north or south pole These devices are especially suited for operation in battery-
2.5 to 3.5 V battery operation operated, hand-held equipment such as cellular and cordless
Chopper stabilized telephones, pagers, and palmtop computers. A 2.5 to 3.5 V
Superior temperature stability operation and a unique clocking scheme reduce the average
Extremely low switchpoint drift operating power requirements to less than 15 W with a
Insensitive to physical stress 2.75 V supply.
High ESD protection
Unlike other Hall-effect switches, either a north or south pole
Solid-state reliability
of sufficient strength will turn the output on in the A3212,
Small size
and in the absence of a magnetic field, the output is off. The
Easily manufacturable with magnet pole independence
A3211 provides an inverted output. The polarity independence
and minimal power requirements allow these devices to easily
PACKAGES:
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)
Continued on next page....
Not to scale
SOT23W (LH)
SUPPLY
SWITCH
TIMING
LOGIC
OUTPUT
X
GROUND
Dwg. FH-020-5
Functional Block Diagram
3211-DS, Rev. 25 February 19, 2019
MCO-0000146
DYNAMIC
OFFSET CANCELLATION
SAMPLE
& HOLD
LATCHA3211 and
Micropower, Ultrasensitive
A3212
Hall-Effect Switches
DESCRIPTION (continued)
requirements, component matching, very low input-offset errors, types EH and EL (0.75 and 0.50 mm nominal height) are leadless, LH
and small component geometries. is a 3-pin low-profile SMD, and UA is a three-pin SIP for through-
hole mounting. Packages are lead (Pb) free (suffix, T) with 100%
Four package styles provide magnetically optimized solutions for
matte-tin-plated leadframes.
most applications. Miniature low-profile surface-mount package
SPECIFICATIONS
SELECTION GUIDE
Ambient Temperature State in
[1]
Part Number Packing Package
T (C) Magnetic Field
A
[2][3][4]
A3211EEHLTT 3000 pieces per reel 2 mm 3 mm, 0.75 mm nominal height DFN
[2][4][5]
A3211EELLTT 3000 pieces per reel 2 mm 2 mm, 0.50 mm nominal height DFN
40 to 85 Off
[4]
A3211ELHLTT 3000 pieces per reel 3-pin surface mount SOT23W
[4]
A3211ELHLXT 10000 pieces per 13-in. reel 3-pin surface mount SOT23W
[2][3]
A3212EEHLTT 3000 pieces per reel 2 mm 3 mm, 0.75 mm nominal height DFN
[2][5]
A3212EELLTT 3000 pieces per reel 2 mm 2 mm, 0.50 mm nominal height DFN
A3212ELHLTT 3000 pieces per reel 3-pin surface mount SOT23W 40 to 85
A3212ELHLXT 10000 pieces per 13-in. reel 3-pin surface mount SOT23W
On
A3212EUAT 500 pieces per bulk bag SIP-3 through hole
A3212LLHLTT 3000 pieces per reel 3-pin surface mount SOT23W
A3212LLHLXT 10000 pieces per 13-in. reel 3-pin surface mount SOT23W 40 to 150
A3212LUAT 500 pieces per bulk bag SIP-3 through hole
1
Contact Allegro for additional packaging and handling options.
2
Allegro products sold in DFN package types are not intended for automotive applications.
3
Variant is no longer in production. The device should not be purchased for new design applications. Samples are no longer available.
Date of status change: June 1, 2015 (A3212EEHLT-T), December 1, 2015 (A3211EEHLT-T).
4
For automotive sales, please contact the field applications engineer .
5
Variant is in production but has been determined to be LAST TIME BUY. This classification indicates that the product is obsolete and notice has been given. Sale of this
device is currently restricted to existing customer applications. The device should not be purchased for new design applications because of obsolescence in the near
future. Samples are no longer available. Date of status change: September 1, 2016.
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Notes Rating Units
Supply Voltage V 5 V
DD
Magnetic Flux Density B Unlimited G
Output Off Voltage V 5 V
OUT
Output Current I 1 mA
OUT
Range E 40 to 85 C
Operating Ambient Temperature T
A
Range L 40 to 150 C
Maximum Junction Temperature T (max) 165 C
J
Storage Temperature T 65 to 170 C
stg
2
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com