BU52012NVX-TR Datasheet, PDF (14/20 Pages) Rohm – Unipolar Detection Hall ICs

BU52002GUL,BU52003GUL,BU52012NVX,BU52012HFV,BU52013HFV
BU52002GUL,BU52012HFV
S-Pole
Technical Note
S
N
S
N
N
S
OUT [V]
High
Flux
High
Flux
High
N-Pole
0
Magnetic flux density [mT]
Fig.42 S-Pole Detection
Low
B
Brp S Bop S
S-Pole
BU52002GUL, BU52012HFV detects and outputs for the S-pole only. Since it is unipolar, it does not recognize the N-pole.
BU52003GUL, BU52013HFV
N-Pole
S
S
N
Flux
High
Low
Bop N Brp N
N-Pole
OUT [V]
High
N
N
S
Flux
0
Magnetic flux density [mT]
S-Pole
High
B
Fig.43 N-Pole Detection
BU52003GUL, BU52013HFV detects and outputs for the N-pole only. Since it is unipolar, it does not recognize the S-pole.
The unipolar detection Hall IC detects magnetic fields running perpendicular to the top surface of the package. There is an
inverse relationship between magnetic flux density and the distance separating the magnet and the Hall IC: when distance
increases magnetic density falls. When it drops below the operate point (Bop), output goes HIGH. When the magnet gets
closer to the IC and magnetic density rises, to the operate point, the output switches LOW. In LOW output mode, the
distance from the magnet to the IC increases again until the magnetic density falls to a point just below Bop, and output
returns HIGH. (This point, where magnetic flux density restores HIGH output, is known as the release point, Brp.) This
detection and adjustment mechanism is designed to prevent noise, oscillation and other erratic system operation.
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2010.08 - Rev.C