BU52001GUL_10 Datasheet, PDF (16/20 Pages) Rohm – Omnipolar Detection Hall ICs

BU52001GUL,BU52011HFV,BU52021HFV,
BU52015GUL,BU52025G,BU52051NVX, BD7411G
●Terminal Equivalent Circuit Diagram
OUT , OUT1, OUT2
VDD
Technical Note
Because they are configured for CMOS (inverter) output, the
output pins require no external resistance and allow direct
connection to the PC. This, in turn, enables reduction of the
current that would otherwise flow to the external resistor
during magnetic field detection, and supports overall low
current (micropower) operation.
GND
Fig.41
●Operation Notes
1) Absolute maximum ratings
Exceeding the absolute maximum ratings for supply voltage, operating conditions, etc. may result in damage to or
destruction of the IC. Because the source (short mode or open mode) cannot be identified if the device is damaged in this
way, it is important to take physical safety measures such as fusing when implementing any special mode that operates in
excess of absolute rating limits.
2) GND voltage
Make sure that the GND terminal potential is maintained at the minimum in any operating state, and is always kept lower
than the potential of all other pins.
3) Thermal design
Use a thermal design that allows for sufficient margin in light of the power dissipation (Pd) in actual operating conditions.
4) Pin shorts and mounting errors
Use caution when positioning the IC for mounting on printed circuit boards. Mounting errors, such as improper positioning or
orientation, may damage or destroy the device. The IC may also be damaged or destroyed if output pins are shorted
together, or if shorts occur between the output pin and supply pin or GND.
5) Positioning components in proximity to the Hall IC and magnet
Positioning magnetic components in close proximity to the Hall IC or magnet may alter the magnetic field, and therefore the
magnetic detection operation. Thus, placing magnetic components near the Hall IC and magnet should be avoided in the
design if possible. However, where there is no alternative to employing such a design, be sure to thoroughly test and
evaluate performance with the magnetic component(s) in place to verify normal operation before implementing the design.
6) Slide-by position sensing
Fig.42 depicts the slide-by configuration employed for position sensing. Note that when the gap (d) between the magnet and
the Hall IC is narrowed, the reverse magnetic field generated by the magnet can cause the IC to malfunction. As seen in
Fig.43, the magnetic field runs in opposite directions at Point A and Point B. Since the Omnipolar detection Hall IC can
detect the S-pole at Point A and the N-pole at Point B, it can wind up switching output ON as the magnet slides by in the
process of position detection. Fig. 44 plots magnetic flux density during the magnet slide-by. Although a reverse magnetic
field was generated in the process, the magnetic flux density decreased compared with the center of the magnet. This
demonstrates that slightly widening the gap (d) between the magnet and Hall IC reduces the reverse magnetic field and
prevents malfunctions.
Magnet
Slide
d
Hall IC
L
Fig.42
Flux
A
S
N
Fig.43
B
Flux
10
8
6
4
2
0
-2
-4
-6
-8
-10
0
Reverse
1 2 3 4 5 6 7 8 9 10
Horizontal distance f rom the magnet [mm]
Fig.44
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16/19
2010.01 - Rev.C