HLSR 40-P Open-Loop Hall-Effect Current Sensor

HLSR 40-P Product Overview

The HLSR 40-P is a high-performance open-loop Hall-effect current sensor from LEM, a global leader in current sensing technology. It is designed for electronic measurement of DC, AC, and pulsed currents, with a rated nominal current of 40 A and a maximum measurable range of ±100 A – covering a wide variety of industrial applications.

The sensor uses Hall-effect, open-loop technology and outputs a voltage signal proportional to the measured current. It is compatible with traditional analog systems and easily interfaces with digital controllers. The key advantage is full electrical isolation between the primary and secondary circuits, allowing you to safely and stably obtain current information without interrupting the main power path.

HLSR 40-P Key Highlights

High Accuracy & Linearity

At 25 °C, the HLSR 40-P offers ±1 % accuracy and ±0.5 % linearity, ensuring every measurement is true and reliable. Even in extreme 105 °C environments, accuracy remains stable at ±3.4 %.

Fast Response

An ultra-fast response time of only 2.5 µs lets the sensor instantly capture every current fluctuation and pulse.

Rugged Environmental Tolerance

With a wide operating temperature range from –40 °C to +105 °C, the HLSR 40-P performs consistently in severe cold or sustained high-heat environments.

High Isolation Voltage for Safety

A 4.3 kVrms isolation voltage rating provides robust protection for operators and downstream equipment in high-voltage electrical environments.

Minimalist Design & Low Power

Through-hole PCB mounting occupies only 3.87 cm² of board space and stands just 12 mm high – ideal for high-density integration. Maximum supply current is only 25 mA, reducing system heat dissipation and power costs.

HLSR 40-P Detailed Specifications

HLSR 40-P Wide Range of Applications

Thanks to its 400 kHz bandwidth and low core losses, the HLSR 40-P excels in demanding high-frequency, high-dynamic current sensing applications, such as:

AC variable frequency and servo motor drives – Real-time motor current monitoring for optimised control, accurate torque and speed regulation.

Static converters for DC motor drives – Smooth current control during motor start-up and braking.

Battery-powered equipment and BMS – Precise monitoring of battery charge/discharge current to prevent over-charge/over-discharge and extend battery life.

UPS and switch-mode power supplies – Monitoring input/output current to deliver clean, stable power to downstream loads while improving power management efficiency.

Renewable energy systems – Solar inverter MPPT tracking, combiner box current monitoring, and more.

IoT and environmental monitoring – Embedded in IoT devices for remote current monitoring and early warning, supporting smart manufacturing and smart city infrastructure.

Why Choose the HLSR 40-P?

Among the many current sensors on the market, the LEM HLSR 40-P is trusted by engineers worldwide for these reasons:

Open-loop Hall effect, cost-effective – ±1 % accuracy at a highly competitive price point.

Generous measuring range with safety margin – Up to 100 A, easily handling peak current surges without frequent sensor replacement.

Ultra-compact size saves PCB space – Only 3.87 cm² footprint and 12 mm height – ideal for spaceconstrained designs.

Factory calibrated, ready to use – Every sensor is factory calibrated – no additional tuning needed.

Global technical support and long-term availability – LEM is a trusted leader in current sensing, with worldwide support and full product lifecycle management.