A3230 ALLEGRO [Allegro MicroSystems], A3230 Datasheet - Page 8

• Manufacturer Part Number: A3230
• Description: Chopper-Stabilized Hall-Effect Bipolar Switch
• Manufacturer: ALLEGRO [Allegro MicroSystems]

exhibiting negative switch behavior operate in a similar but
opposite manner. A north polarity fi eld of suffi cient strength,
> B
the result is that V
the fi eld is reduced beyond the B
back to the low state.
The A3230 is designed to attain a small hysteresis, and thereby
provide more sensitive switching. Although this means that
true latching behavior cannot be guaranteed in all cases, proper
switching can be ensured by use of both south and north mag-
netic fi elds, as in a ring magnet.
Bipolar devices adopt an indeterminate output state when
powered-on in the absence of a magnetic fi eld or in a fi eld that
lies within the hysteresis band of the device. The correct state is
attained after the fi rst excursion beyond B
For more information on Bipolar switches, refer to Application
Note 27705, Understanding Bipolar Hall Effect Sensors.
A3230-DS
RP
, (more north than B
OUT
switches high, as shown in panel C. When
RP
) is required for operation, although
OP
Chopper-Stabilized Hall Effect Bipolar Switch
level, the device switches
OP
or B
RP
.
A3230
Applications
It is strongly recommended that an external bypass capacitor be
connected (in close proximity to the Hall sensor) between the
supply and ground of the device to reduce both external noise
and noise generated by the chopper stabilization technique. As is
shown in Panel B of fi gure 1, a 0.1µF capacitor is typical.
Extensive applications information on magnets and Hall-effect
sensors is available in:
• Hall-Effect IC Applications Guide, AN27701,
• Hall-Effect Devices: Gluing, Potting, Encapsulating, Lead
• Soldering Methods for Allegro’s Products – SMT and Through-
All are provided in Allegro Electronic Data Book, AMS-702 and
the Allegro Web site: www.allegromicro.com
Welding and Lead Forming, AN27703.1
Hole, AN26009
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
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