How to judge the quality of the Hall element _ How to test the Hall element is good or bad (multimeter)

Hall elements can be fabricated from a variety of semiconductor materials, such as Ge, Si, InSb, GaAs, InAs, InAsP, and multilayer semiconductor heterostructure quantum well materials. It is a magnetic sensor based on the Hall effect. They can be used to detect magnetic fields and their changes, and can be used in a variety of applications related to magnetic fields.

Hall elements have many advantages, they are solid in structure, small in size, light in weight, long in life, easy to install, low in power consumption, high in frequency (up to 1MHZ), resistant to vibration, not afraid of dust, oil, water vapor and salt spray. Contaminated or corroded.

1, Hall coefficient (also known as Hall constant) RH

When the magnetic field is not too strong, the Hall potential difference UH is proportional to the product of the excitation current I and the magnetic induction B, and is inversely proportional to the thickness δ of the Hall plate, that is, UH = RH * I * B / δ, where RH is called It is the Hall coefficient, which indicates the strength of the Hall effect. Further, RH = μ * ρ, that is, the Hall constant is equal to the product of the resistivity ρ of the Hall sheet material and the electron mobility μ.

2, Hall sensitivity KH (also known as Hall product sensitivity)

The Hall sensitivity is proportional to the Hall coefficient and inversely proportional to the thickness δ of the Hall plate, ie KH = RH / δ, which typically characterizes the Hall constant.

3, Hall rated excitation current

The excitation current flowing when the Hall element itself rises by 10 ° C is called the rated excitation current.

4, Hall maximum allowable excitation current

The excitation current corresponding to the maximum temperature rise allowed by the Hall element is referred to as the maximum allowable excitation current.

5, Hall input resistance

The value of the resistance between the Hall excitation electrodes is called the input resistance.

6, Hall output resistance

The resistance between the Hall output electrodes is called the input resistance.

7, the temperature coefficient of resistance of the Hall element

The relative rate of change of resistance, measured by α, in units of %/°C, for every 1 °C change in ambient temperature without applying a magnetic field.

8, Hall non-equal potential (also known as Hall offset zero)

In the absence of an applied magnetic field and the Hall excitation current is I, the measured Hall potential difference at the output end is referred to as the unequal potential.

9, Hall output voltage

In the case where the applied magnetic field and the Hall excitation current are I, the measured Hall potential difference at the output end is referred to as the Hall output voltage.

10, Hall voltage output ratio

Hall ratio of non-equal potential to Hall output potential

11, Hall parasitic DC potential

When the applied magnetic field is zero and the Hall element is excited by AC, the Hall electrode output has a constant current potential, which is called a parasitic DC potential, in addition to the AC unequal potential.

12, Hall is not equipotential

In the case where there is no applied magnetic field and the Hall excitation current is I, the relative rate of change of the unequal potential is changed every 1 °C of the ambient temperature.

13, Hall potential temperature coefficient

In the case where the applied magnetic field and the Hall excitation current are I, the relative rate of change of the unequal potential is changed every 1 °C of the ambient temperature. It is also the temperature coefficient of the Hall coefficient.

First, the quality of the Hall element is judged

1. Change the size of the magnetic field. The quality of the linear Hall element (eg: A1302, SS495A)

When the Hall element is energized, the output terminal is connected to the voltmeter. When the magnet gradually approaches the linear Hall element from far to near, the output voltage of the linear Hall element gradually changes from small to large, which indicates that the linear Hall element is good. If the magnet gradually approaches the linear Hall element from far to near, the output voltage of the linear Hall element remains unchanged, indicating that the linear Hall element has been damaged.

2. Change the current of the constant current source of the linear Hall element to judge whether the linear Hall element is good or bad.

The magnet remains stationary (ie, a fixed magnetic field is added to the linear Hall element), so that the current of the linear Hall element constant current source gradually changes from zero to the rated current (cannot exceed the rated current of the linear Hall element) At this time, the output voltage of the linear Hall element also gradually changes from small to large, which is said to be good if the constant current of the linear Hall element gradually changes from zero to the rated current. At this time, the voltage of the linear Hall element remains unchanged, which indicates that the linear Hall element is damaged.

Second, the quality of the single-pole switching Hall element detection (such as: A1104, SS443, US5881)

The unipolar switching Hall element is energized 5V, and the output terminal is connected in series. When the magnet is away from the switching Hall element, the output voltage of the switching Hall element is high level (+5V), when the magnet is close (usually all N pole) When the Heller component is switched, the output voltage of the switching Hall element is low level (+0.2V or so), which indicates that the switch-opening Hall element is good. If you do not recognize or leave the Hall switch, the output level of the Hall switch remains unchanged, indicating that the Hall switch is damaged.

Third, the detection of good or bad bipolar Hall switching components (A3212, SS441, US4881)

When the N or S pole of the magnet is close to the Hall switch, the output is high level or low level (generally low level), and then the Hall element is taken back, the level goes high, indicating that the Hall element is Ok. If you do not recognize or leave the Hall switch, the output level of the Hall switch remains unchanged, indicating that the Hall switch is damaged.

4. Good or bad detection of bipolar latched Hall switching components (A1120, SS41F, US1881, MH181)

When the N or S pole of the magnet is close to the Hall switch, the output is high or low, then the Hall element is taken back, the level remains unchanged, and the opposite polarity is obtained with the opposite magnetic pole. It is stated that the Hall element is good. If the Hall element is close to the obtained level, it will not be latched after the magnet leaves, indicating that the Hall is bad. When the magnet is close to the Hall with the opposite polarity, it is not available. The other polarity is close to the Hall to get the opposite level, then the Hall switch is also bad.

User left bank east answer:

First, use a multimeter to measure the resistance between his legs. Too big or too small is bad, usually only a few hundred ohms to about 1K.

Secondly, it will be powered on. Generally, his resistance is basically good, but for the sake of accuracy, you can use the power meter to measure it. You can power the Hall 1.2v/5ma and measure the output of it. The voltage between the two legs also has their respective voltages to ground.

Netizen 甄好斌 answer:

Hall faces to itself (seal face), the pin is down, from left to right: positive (switch Hall 4.5V to 24V, linear Hall 5V), negative, input (signal), at the positive and output Connect the resistor (1 to 10K).

Indirect LED and indirect one LED, measure the voltage with a multimeter, the high level is equal to the low voltage of the power supply is equal to zero. After the power is turned on, use the magnet to move closer to or away from the Hall to see if the LED changes in illumination. If there is a change, it will be good. If it is not changed, it will be bad.