A3212 Datasheet, PDF (1/13 Pages) Allegro MicroSystems – MICROPOWER, ULTRA-SENSITIVE HALL-EF FECT SWITCH

A3212
2 x 2 mm MLPD
Package A3212EELLT-T
Approximate actual size
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V_DD .............................. 5 V
Magnetic Flux Density, B .......... Unlimited
Output Off Voltage, V_OUT ...................... 5 V
Output Current, I_OUT ........................... 1 mA
Junction Temperature, T_J ................ +170°C
Operating Temperature, T_A
Range 'E-' .................... -40°C to +85°C
Range 'L-' .................. -40°C to +150°C
Storage Temperature Range,
T_S .............................. -65°C to +170°C
Caution: These CMOS devices have input
static protection (Class 3) but are still sus-
ceptible to damage if exposed to extremely
high static electrical charges.
MICROPOWER, ULTRA-SENSITIVE
HALL-EFFECT SWITCH
The A3212 integrated circuit is an ultra-sensitive, pole independent Hall-effect
switch with a latched digital output. This sensor is especially suited for opera-
tion in battery-operated, hand-held equipment such as cellular and cordless
telephones, pagers, and palmtop computers. A 2.5 volt to 3.5 volt operation and a
unique clocking scheme reduce the average operating power requirements to less
than 15 µW with a 2.75 volt supply.
Unlike other Hall-effect switches, either a north or south pole of sufficient
strength will turn the output on; in the absence of a magnetic field, the output
is off. The polarity independence and minimal power requirement allow these
devices to easily replace reed switches for superior reliability and ease of manu-
facturing, while eliminating the requirement for signal conditioning.
Improved stability is made possible through chopper stabilization (dynamic off-
set cancellation), which reduces the residual offset voltage normally caused by
device overmolding, temperature dependencies, and thermal stress.
This device includes on a single silicon chip a Hall-voltage generator, small-sig-
nal amplifier, chopper stabilization, a latch, and a MOSFET output. Advanced
BiCMOS processing is used to take advantage of low-voltage and low-power
requirements, component matching, very low input-offset errors, and small com-
ponent geometries.
Four package styles provide magnetically optimized solutions for most appli-
cations. Miniature low-profile surface-mount package types EH and EL
(0.75 and 0.50 mm nominal height) are leadless, LH is a leaded low-profile
SMD, and UA is a three-lead SIP for through-hole mounting. Each package is
available in a lead (Pb) free version (suffix, –T) with 100% matte tin plated lead-
frame. EL package for limited release, engineering samples available.
FEATURES
■
Micropower Operation
■
Operation with North or South Pole
■
2.5 V to 3.5 V Battery Operation
■
Chopper Stabilized
Superior Temperature Stability
Extremely Low Switch-Point Drift
Insensitive to Physical Stress
■
ESD Protected to 5 kV
■
Solid-State Reliability
■
Small Size
■
Easily Manufacturable with Magnet Pole Independence