ALPS unveil Low Loss PCB Mount High-Precision Current Sensor

With growing importance attached to energy savings in recent years, efforts to reduce the power consumption of various electronic devices have picked up momentum. In particular, motors are said to account for around 60% of power consumption in Japan, suggesting that lowering the amount of power consumed by motors would have significant energy saving benefits.

As a result, attention is focusing on inverters, which can reduce power consumption through fine control of motor operation and which are expected to have benefits even for equipment that is not motor-driven, for example by helping to create high-efficiency power conditioners. A key device for achieving high-precision inverter control is the current sensor.

Current sensors generally employ one of two approaches-measurement based on shunt resistance, or measurement of the magnetic flux generated around a current. The DC current transformer approach employing flux measurement is widely used to achieve high-precision detection while keeping down costs. The DCCT approach is generally used with magnetic elements that have low sensitivity and therefore a magnetic core is required to concentrate flux around the current. This results in larger and heavier equipment designs. In addition, existing current sensors became hot quickly due to high resistance in the primary conductor, leading to associated power loss.

The GCBC Series is a current sensor for PCB mounting and is the smallest and lightest in the industry. Use of a proprietary high-sensitivity magnetic sensor element (GMR element) eliminates the need for a core to concentrate magnetic flux, enabling compact dimensions of 13.4 × 15.7 × 7.2mm (W×D×H) and weight of 3g. Furthermore, proprietary magnetic control plates positioned around the sensor element ensure both high sensitivity and resistance to outside disturbance.

Resistance in the primary conductor is also the industry’s lowest at 60µΩ, a 40% reduction compared to existing current sensors of other companies. This reduces conductor heat generation, helping to lower power loss associated with current measurement.

Key Features:

•Smallest and lightest in the industry due to use of a high-precision magnetic element
•High-precision detection achieved with low resistance and low heat generation
•Highly resistant to disturbance, facilitating equipment design

Principal Applications:

•Motor drivers and general-purpose inverters
•Power-conditioning systems
•Server power supplies
•Packaged air-conditioning units
•NC machine tools

Specifications:

Model: GCBC Series
Dimensions (W×D×H): 13.4 × 15.7 × 7.2mm
Weight: 3.0g
Supply voltage: +5V ±0.15V
Max. continuous current: DC ±50A
Current measurement range: Up to DC ±150A
Operating temperature: –50 to +105°C
Storage temperature: –50 to +105°C
Offset voltage: 2.5V
Linearity: ±0.5%FS max.
Response time: 1µs
Primary conductor resistance: 60µΩ