US5781LSE Melexis Inc, US5781LSE Datasheet - Page 25

• Manufacturer Part Number: US5781LSE
• Description: IC HALL EFFECT SWITCH TSOT-23
• Manufacturer: Melexis Inc
• Type: Unipolar Switchr

Specifications of US5781LSE

• 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: SOT-23
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: US5781LSETR

Graph 8, Slide-by with Magnet A
Change in Activation Distance With TC
There is a 17% difference in flux density over the entire temperature range compared with the fixed-tem-
perature case in Graph 7. Note that because of the negative temperature coefficient of the magnet, the neg-
ative temperature (-40
flux density.
Graph 9 shows how the air gap tolerance and temperature coefficient add together and cause tolerance
buildup in the Hall Effect system.
Graph 9, Slide-by Method with Magnet A
Change in Activation distance with Air Gap & TC
The two plotted lines in Graph 9 show the minimum and maximum possible cases when temperature and
air gap are considered. The overall difference in distance between min. BRP and max. BOP is slightly
larger because of the sum of tolerances being considered. This design example has shown the tolerance
buildup of air gap, benefits of slope, Hall IC BOP to BRP variations and magnet Tc. We have not con-
sidered the variation of initial flux density, which you must obtain from a magnet supplier.
-1.5
-1
-0.75
-1
-0.5
-0.5
Distance (mm)
-0.25
Distance (mm)
-100
-200
-300
-400
0
400
300
200
100
C) adds flux density to the magnet, while the positive temperature (85
-100
-200
-300
-400
0
400
300
200
100
0
0
0
0.5
0.25
A ir Gap = 1.5mm @ -40
Air Gap = 2.5mm @ 80
0.5
1
0.75
Temp -40
1.5
Temp = 85
Temp = 25
1
o
C
o
o
o
o
C
C
C
C
3-33
Section 3 - Applications
0
C) reduces