AN48810B
5
SPC00016AEB
■Caution on Use of Hall ICs
The Hall ICs are often used to detect movement. In such cases, the position of the Hall IC may be changed by
exposition to shock or vibration over a long period of time, and it causes the detection level change. To prevent this, fix
the package with adhesives or fix it on a dedicated case.
1. A case using an adhesive
Some kinds of adhesive generate corrosive gas (such as chloric gas) during curing. This corrosive gas corrodes the
aluminum on the surface of the Hall IC, and may cause a functional defect of disconnection.
If Hall IC is to be sealed after installation, attention should be given to the adhesive or resin used for peripherals
and substrate cleaner, as well as to the adhesive used for Hall IC installation. Please confirm the above matter to those
manufacturers before using.
We could not select the specified adhesive, for we find it difficult to guarantee the ingredient of each adhesive.
2. Power supply line/Power transmission line
If a power supply line/power transmission line becomes longer, noise and/or oscillation may be found on the line.
In this case, set the capacitor of 0.1 µF to 10 µF near the Hall IC to prevent it.
If a voltage of 18 V or more is thought to be applied to the power supply line (flyback voltage from coil or the ignition
pulse, etc.), avoid it with external components (capacitor, resistor, Zener diode, diode, surge absorbing elements, etc.).
3. On mounting of the surface mount type package (MINI-3DR)
When mounted on the printed circuit board, the Hall IC may be highly stressed by the warp that may occur from
the soldering. This may also cause a change in the operating magnetic flux density and a deterioration of its resistance
to moisture.
4. VCC and GND
Do not reverse VCC and GND. If the VCC and GND pins are reversely connected, this IC will be destroyed. If the
IC GND-pin voltage is set higher than other pin voltage, the IC configuration will become the same as a forward
biased diode. Therefore, it will turn on at the diode forward voltage (approximately 0.7 V), and a large current will
flow through the IC, ending up in its destruction. (This is common to monolithic IC.)
5. Cautions on power-on of Hall IC
When a Hall IC is turned on, the position of the magnet or looseness may change the output of a Hall IC, and a pulse
may be generated. Therefore, care should be given whenever the output state of a Hall IC is critical when the supply
power is on.
6. On fixing a Hall IC to holder
When a Hall IC is mounted on the printed circuit board with a holder and the coefficient of expansion of the holder
is large, the lead wire of the Hall IC will be stretched and it may give a stress to the Hall IC.
If the lead wire is stressed intensely due to the distortion of holder or board, the adhesives between the package and
the lead wire may be weakened and cause a minute gap resulting in the deterioration of its resistance to moisture.
Sensitivity may also be changed by this stress.
7. On using flux in soldering
Choose a flux which does not include ingredients from halogen group, such as chlorine, fluorine, etc. The
ingredients of halogen group may enter where the lead frame and package resin joint, causing corrosion and the
disconnection of the aluminum wiring on the surface of an IC chip.
8. In case of the magnetic field of a magnet is too strong
Output may be inverted when applying a magnetic flux density of 100 mT or more. Accordingly, magnetic flux
density should be used within the range of 100 mT.
9. On surface treatment of mini-mold package
Surface treatment is available in either smooth or dull finish.
10. On soldering of the surface mount type package
Surface mounting type Hall ICs are apt to change its electrical characteristics due to the stress from soldering at
mounting. Therefore, avoid the mounting by flow (dipping) and a soldering iron. Please mount it by reflow soldering
abiding by its recommended conditions.
CorrectWrong