Current sensor: Products: Homepage of Asahi Kasei Microdevices Asahi Kasei Microdevices Magnetic Sensors

CQ series - CQ-121E, 131E

Operation principle

A magnetic field is generated by the current flowing through the primary conductor. (Fig. 1)
The magnetic field generated is converged by the core, and the parallel magnetic fields proportional to the current are created by the gap provided at the center. (Fig. 2)
The current value proportional to the magnetic flux density can be detected by positioning the linear hall effect IC on the gap. (Fig. 3)

[Fig. 1]

[Fig. 2]

[Fig. 3]

Special features

Current sensor using highly sensitive magnetic sensor

InAs hall sensor in unique quantum well structure
Hall effect IC with a hall sensor and amplifier integrated into one package
Quick response speed (CQ-121E, 131E: Max. 5us)
Electrical isolation by the primary conductor

Simple structure

Reduced number of components, with high reliability
External amplifier circuit is unnecessary.
Direct input to CPU A/D is possible.

Excellent magnetic noise resistance

Because only the magnetic flux to be measured is converged, the resistance to external magnetic noise is excellent.

Compliance with the IEC standards

Operating ambient temperature: -30 to 80°C

Main applications:

Air conditioning and industrial machinery; various inverters

Products

Type

Small core type current sensor

20A type

30A type

Improvement of temperature characteristics

CQ-121E

CQ-131E

Main specifications

Parameter	CQ-121E	CQ-131E	Unit
Operating temperature range	-30~80		°C
Storage temperature range	-30~85		°C
Power supply voltage	3~5.5		V
DC maximum conduction current	-30~30		A
Rated input current Note 1)	-25~25	-50~50	A
Output unsaturation range	-30~30	-60~60	A
Consumed current	9(Typ.)		mA
Sensitivity voltage	63.5(Typ.)	27(Typ.)	mV/A
Neutral-point potential (I = 0A)	2.35~2.65		V
Linearity	≦1.0		%F.S.
Sensitivity voltage temperature drift	≦5		%
Neutral-point potential temperature drift	≦0.5		mV/°C
Frequency response (-3 dB)	100(Typ.)		kHz
Pulse response	≦5		µs
Withstand voltage (60 sec)	1.5(Typ.)		kV

Note 1) Shall be within the linearity assurance range.