US4881KUA MELEXIS [Melexis Microelectronic Systems], US4881KUA Datasheet - Page 5

• Manufacturer Part Number: US4881KUA
• Description: Bipolar Hall Switch Low Voltage & Very High Sensitivity
• Manufacturer: MELEXIS [Melexis Microelectronic Systems]

9 Detailed General Description
Based on mixed signal CMOS technology, Melexis US4881 is a Hall-effect device with very high magnetic
sensitivity. It allows using generic magnets, weak magnets or larger air gap.
The chopper-stabilized amplifier uses switched capacitor techniques to suppress the offset generally
observed with Hall sensors and amplifiers. The CMOS technology makes this advanced technique possible
and contributes to smaller chip size and lower current consumption than bipolar technology. The small chip
size is also an important factor to minimize the effect of physical stress.
This combination results in more stable magnetic characteristics and enables faster and more precise design.
The operating voltage from 2.2V to 18V, low current consumption and large choice of operating temperature
range according to “L”, “K” and “E” specification make this device suitable for automotive, industrial and
consumer low voltage applications.
The output signal is open-drain type. Such output allows simple connectivity with TTL or CMOS logic by using
a pull-up resistor tied between a pull-up voltage and the device output.
10 Unique Features
The US4881 exhibits bipolar magnetic switching characteristics. Therefore, it operates with both south and
north poles.
Depending on the magnetic switching points, the device may also behave as a unipolar positive switch (B
and B
and low by only using one magnetic pole. In such case, removing the magnetic field changes the output level.
In latch, positive or negative switch behaviour, a magnetic hysteresis B
a minimal value. This hysteresis prevents output oscillation near the switching point.
3901004881
Rev 011
RP
strictly positive) or negative switch (B
Unipolar positive switch characteristic
Latch characteristic
Typically, the device behaves as a latch with symmetric
operating and release switching points (B
magnetic fields with equivalent strength and opposite direction
drive the output high and low.
Removing the magnetic field (B→0) keeps the output in its
previous state. This latching property defines the device as a
magnetic memory.
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and B
RP
Low Voltage & Very High Sensitivity
strictly negative). That is the output can be set high
Unipolar negative switch characteristic
HYST
keeps B
Bipolar Hall Switch
OP
OP
and B
=|B
US4881
RP
RP
|). This means
separated by
Data Sheet
Feb/06
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