US4881ESE Melexis Inc, US4881ESE Datasheet - Page 22

• Manufacturer Part Number: US4881ESE
• Description: IC HALL SW BIPO NORTH POLE SOT23
• Manufacturer: Melexis Inc
• Type: Bipolar Latchr

Specifications of US4881ESE

• Sensing Range: 6mT Trip, -6mT Release
• Voltage - Supply: 2.2 V ~ 18 V
• Current - Supply: 5mA
• Current - Output (max): 50mA
• Output Type: Digital, Open Drain
• Operating Temperature: -40°C ~ 85°C
• Package / Case: SOT-23
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: US4881ESETR

Graph 2, Slide-by Method with Magnet A Steep Slope vs. Shallow Slope
Tolerances Build-up
The following examples incorporate many different factors in order to show how tolerance buildup can
affect a Hall Effect system. Air gap tolerance, temperature range, and the temperature coefficient of the
magnet will cause the activation distance of a US5881 EUA to vary, thus impacting switching accuracy.
Tolerances:
The US5880 Hall-Effect Switch has a maximum BOP of 250 Gauss and a minimum BRP of 140 Gauss.
If this part were to be actuated by sample Magnet B at an air gap of 3mm and 6mm, the following results
would occur (See Graphs 3 and 4). Each graph has an air gap tolerance of +1mm which could be due to
a loosely fitted mechanical assembly. Notice the difference in distance and slope between Graphs 3 and
4.
Graph 3, Slide-by With Magnet A, Shallow Slope
Section 3 - Applications
1000
800
600
400
200
1200
1000
0
800
600
400
200
Air gap Tolerance = 3mm. +1 mm. and 6mm. +1mm.
US5881EUA B OP /B RP Range = 95G min. B RP to 300G max. B OP
(IC Temperature Selection (EUA) = -40
Temperature Range = -40
Magnet Temp. Coefficient = -0.1098%/
0
0
2
Distance (mm)
4
1
6
2
8
3
Always "ON"
10
4
12
Always "OFF"
5
Distance (mm)
14
o
Air Gap = 5 mm
Air Gap = 6 mm
Air Gap = 7 mm
C to 85
6
16
7
18
o
C
8
20
o
o
9
C
C to 85
Air Gap = 2.5mm
Air Gap = 5mm
3-30
10
o
C)
Graph 2 shows what
happens to the slope of a
flux density vs. distance
graph by using different air
gaps with the same magnet
configuration.