10/15

BU52069GWZ

TSZ02201-0M2M0F414040-1-2

© 2014 ROHM Co., Ltd. All rights reserved.

7.Nov.2014 Rev.001

www.rohm.com

TSZ22111

• 15 • 001

Slide-by Position Sensing

Figure 19 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 Figure 20, the magnetic field runs in opposite directions at Point A and Point B. Since the unipolar detection Hall IC can

detect the S-pole at Point A and the N-pole at Point B, the sensor can switch the output ON as the magnet slides by in the

process of position detection. Figure 21 plots magnetic flux density during the magnet slide-by. Although a reverse magnetic

field was generated in the process, the magnetic flux density decreases 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.

Position of the Hall Element

(Reference)

Footprint Dimensions

(Optimize footprint dimensions to the board design and soldering condition)

I/O Equivalence Circuit

Symbol

Reference

value

e

0.40

b3

φ0.20

SD

0.20

SE

0.20

-10.0

-5.0

0.0

5.0

10.0

0

2

4

6

8

10

Horizontal Distance from the Magnet

[mm]

The Hall ICs output pins are configured for CMOS (inverter)

output removing the need for external resistance and allow

direct connection to the host. Removing the need for external

resistors allows for reduction of the current that would

otherwise flow to the external resistor during magnetic field

detection thereby supporting an overall lower current

(micropower) operation.

GND

OUT

Figure 22

L

Figure 19

d

Magnet

Hall IC

Slide

Reverse

Figure 21. Magnetic Flux Density vs Horizontal

Distance from the Magnet

Figure 20

B

S

A

N

Flux

Flux

(UNIT: mm)

0.40

0.40

0.25

UCSP35L1

e

SD

b3

UCSP35L1

(UNIT: mm)