US1881ESE Melexis Inc, US1881ESE Datasheet - Page 21

• Manufacturer Part Number: US1881ESE
• Description: IC LATCH CMOS MP TSOT23-3
• Manufacturer: Melexis Inc
• Type: Bipolar Latchr

Specifications of US1881ESE

• Sensing Range: 9.5mT Trip, -9.5mT Release
• Voltage - Supply: 3.5 V ~ 24 V
• Current - Supply: 5mA
• Current - Output (max): 50mA
• Output Type: Digital, Open Drain
• Operating Temperature: -40°C ~ 85°C
• Package / Case: TSOT-23-3, TSOT-3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: US1881ESETR

Cost
Hall IC cost will vary depending on the temperature specifications of BOP, BRP and Bhys. A loosely
specified device may easily be one half to one third the cost of a tightly specified device, yet perform the
same job. By providing steep slopes of flux density vs. distance and using strong magnets, the Hall IC
cost may be reduced.
Temperature Range
Hall Effect Sensors are categorized into different temperature ranges for the use in application-specific
design. It is very important that the Hall IC you select complies with your system’s ambient temperature.
Position Tolerance
Depending on the application and how it is assembled, the position of components, such as the magnet,
Hall IC and mechanical assembly, will determine the mechanical variations of the system. Some systems
are more tolerant of changes in air gap and lateral motion than others.
Position Switching Accuracy
The requirement in angular (degree) or linear position ultimately governs the magnetic circuit and Hall
IC specifications. That is if switching must repeat 0.1250in. or 0.1mm then the Hall IC specification
will be much tighter than if the specification is 1.00 or 1.0mm.
Tolerance Buildup
Tolerance buildup is the sum of all the variables that determine the operate point and release point of a
Hall IC. These variables include position tolerance,temperature coefficient, wear and aging of the assem-
bly and magnet variations.
Total Effective Air Gap
As mentioned previously, both Magnet A and Magnet B in the design Kit are composed of the same mate-
rial. Although the two magnets have similar characteristics, due to the difference in size and shape
total Effective Air Gap (TEAG) will have different effects on each magnets’ flux density vs. distance
curve.
TEAG is defined as the sum of active area depth and the distance between the Hall IC’s branded face to
the surface of the magnet. TEAG = Air Gap + Active Area Depth. Active area depth is simply the dis-
tance from the branded face of the sensor to the actual Hall Cell within it. The TEAG should be as small
as the physical system will allow, after taking into consideration factors such as the change in air gap with
temperature due to mounting, vane or interrupt thickness and wear on mounting brackets.
Graph 2 is given to show the effects of air gap on the slope of a graph using a single-pole slide-by con-
figuration with magnet A.
Section 3 - Applications
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