CQ-2 Series Current Sensors Frequently Asked Questions


How much current can be flown in CQ-2 series?

It is possible to flow current of up to 50Arms in CQ-206x, CQ-223x, and CQ-233x, 20Arms in CQ-209x.

How much pulse current can be flown in CQ-2 series?

It has been confirmed by an experiment in AKM labo that CQ-2 series did not break at a pulse current of 500A, 100us.

What is the difference of maximum primary current and linear sensing range?

Maximum primary current indicates the current value which can be applied for a long time in current sensor and depends on the cross-sectional area of the primary conductor. CQ-2 series can be damaged when they have been used for a long time over the maximum effective current value. If current flows at a short period within msec, such as an over current, CQ-2 series is not damaged.
Linear sensing range is a current range where linear output of the current sensor is guaranteed. Output will be saturated when the current value exceeds the linear sensing range, and will return to normal output when the current value returns within the linear sensing range.

What is the difference between the lineups of CQ-2 series?

Please refer to the selection guide here.

What kind of packages does AKM use?

CQ-2 series use AKM's original package called AI-Shell which has a simple structure with case, the Hall sensor, magnetic core, and primary conductor.

Can CQ-2 series detect unipolar current? (e.x. current detection of 0 to 40A)

CQ-2 series can detect unipolar current. Moreover, there are product lineups which are specialized in unipolar detection such as CQ-206B and CQ-209B. Please select the product which is most suited to your requirements.

How small is a current resolution?

Current resolution of each product is shown in here.

What safety standards CQ-2 series have?

CQ-223x and CQ-233x series have been certified with IEC/UL-60950 and UL-508 by the international certification association. They are also compliant with IEC-62109. CQ-206x and CQ-209x are compliant with IEC-60950, but there is no plan to certificate them.

Are CQ-2 series compliant with halogen-free/RoHS?

CQ-2 series are compliant with halogen-free/RoHS.

Is it possible to sense both DC current and AC current?

They can sense both DC current and AC current.

What does "ratiometric" mean?

Ratiometric output means the output characteristic which varies in proportional to the power supply voltage. In the case that the output of a current sensor is captured by an A/D converter, ratiometric output can reduce the A/D conversion error due to variations of the reference voltage of A/D converter, by maiking reference voltage from the same power source as the current sensor. Both sensitivity and output voltage of AKM current sensors have the ratiometric characteristics.
Recommended circuit is shown in Fig1.


Fig.1. Recommended external circuits of CQ-2 series


What is the ESD tolerance?

CQ-2 series have the ESD tolerance which is more than 2000V by human body model and more than 200V by machine model.

Do CQ-2 series support the Pb-free product?

CQ-2 series are compliant with Pb-free.

What happens if a load capacitance over 100pF is applied to CQ-2 series?

CQ-2 series do not output the correct value because of the oscillation of output. It is no problem to add a low-pass filter.

What happens if a load current over +/-0.5mA is applied to CQ-2 series?

CQ-2 series do not output the correct value because output of CQ-2 series cannot drive the load.

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