US5781LUA Melexis Inc, US5781LUA Datasheet - Page 9

• Manufacturer Part Number: US5781LUA
• Description: IC HALL EFFECT SWITCH TO-92UA
• Manufacturer: Melexis Inc
• Type: Unipolar Switchr

Specifications of US5781LUA

• Sensing Range: 15mT Trip, 3.5mT Release
• Voltage - Supply: 3.5 V ~ 24 V
• Current - Supply: 5mA
• Current - Output (max): 50mA
• Output Type: Digital, Open Drain
• Operating Temperature: -40°C ~ 150°C
• Package / Case: TO-92UA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

R
Figure 7, Rotary Slide-by Switch
The Rotary Slide-by Switch in Figure 7 is generally used to measure rotary speed to synchronize switch-
ing with position. The Hall IC is activated by a rotating magnet. When the South pole passes by the Hall
IC, the IC is switched ON. As the North pole passes, the Hall IC is switched OFF. The solid circular mag-
net, shown in Figure 7A, is called a Ring Magnet. A ring magnet has alternating North and South poles.
Ring magnets may have from two poles to thirty-six or more, depending on size. Graph 1, below illus-
trates the transition between North and South polarity at various air gaps. Notice the transition point is
similar at the various gaps.
Graph 1, Rotary Slide-by vs. Air gap
otary Slide-by Switch
N
-100
-150
150
100
-50
50
0
0
S
Figure 7A
50
N
100
A-11
S
Rotation in Degrees
150
3-7
6 Pole Ring Magnet
200
250
300
Section 3 - Applications
350
400
S
Figure 7B
0 Airgap
0.025" airgap
0.050" Airgap
0.100" Airgap
0.150" airgap
A-12
N