US5781LSE Melexis Inc, US5781LSE Datasheet - Page 26

• 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

The Push-Pull Method
Graph 10 shows the push-pull method. A South magnetic pole, perpendicular to the branded face, is used
in conjunction with a North magnetic pole at the opposite face. The two magnets in the single-pole slide-
by configuration are moved in the X-direction with respect to a stationary Hall IC.
Graph 10, Push-Pull Activation Using Slide-by Method with Magnet A
The Push-Push Method
The push-push method is similar in configuration to push-pull, but requires a South pole located at the
branded face along with a South pole at the opposite side of the Hall IC. When the Hall IC is centered
between these two South magnetic poles, their flux density cancels out leaving zero flux density at this
position. If the two magnets maintain the same distance between each other and are moved in the head-
on method in either direction, the flux vs. distance graph will be linear.
Graph 11, Push-Push Activation Using Head-On Mode
The US3881EUA Hall Effect Latch has maximum BOP of 90 Gauss and a minimum BRP of -90Gauss
over the temperature range of -400C to 850C. Due to the temperature coefficient of -0.1098%/0C, the
magnet will have a difference in flux density of 8% over this distance range. The distance necessary to
fully actuate a US3881EUA Hall Effect Latch is approximately 0.35mm from max. BOP to min. BRP.
This is an extremely large increase in performance from the previous example.
Section 3 - Applications
-1
-15
-13
-0.75
-11
Min. Brp
-9
-0.5
-7
-0.25
-5
Distance (mm)
Distance (mm)
-3
-100
-150
-200
-250
-300
-350
350
300
250
200
150
100
-50
1400
1200
1000
50
-200
800
600
400
200
0
-1
0
0
1
0.25
3
5
Max. Bop
0.5
7
Maximum
Temp = 25
Temp = 85
Temp = -40
Minimum
9
Gauss
0.75
11
3-34
13
The Air Gap for
both magnets is
approximately 6.3mm
o
o
C
C
o
C
1
15
B
90
10
OP
The Air Gap for
both magnets is
approximately 3mm
B
-10
-90
RP
B
100
100
hys