US2884 Melexis Company, US2884 Datasheet - Page 5

• Manufacturer Part Number: US2884
• Description: Bipolar Hall Switch - Very High Sensitivity
• Manufacturer: Melexis Company

9 Detailed General Description
Based on mixed signal CMOS technology, Melexis US2884 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 technique 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 wide operating voltage from 3.5V to 24V, wide operating temperature according to “L” specification and
low current consumption make this device especially suitable for automotive and BLDC motor 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 US2884 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.
3901002884
Rev 004
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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Bipolar Hall Switch – Very High Sensitivity
Page 5 of 11
and B
RP
strictly negative). That is the output can be set high
Unipolar negative switch characteristic
HYST
keeps B
OP
OP
and B
=|B
US2884
RP
RP
|). This means
separated by
Data Sheet
Jan/06
OP