HO 40-NP-0100 , HO40-NP-0100

LEM HO 40-NP-0100 HO-NP Series Open Loop Hall Effect Current Transducer

LEM HO 40-NP-0100 Product Overview

The HO 40-NP-0100 is an open-loop Hall effect current transducer from LEM's HO-NP Series, designed for the electronic measurement of DC, AC, and pulsed currents with galvanic isolation between the primary and secondary circuits. This through-hole PCB-mount transducer features a multi-range primary conductor design with four pins, allowing the nominal current to be set to 10 A, 20 A, or 40 A depending on the PCB connection configuration . The device is factory calibrated and features a compact design measuring 20 x 41 x 27 mm with 8 mm creepage and clearance distances (CTI 600) .

Rated for 40 A nominal with a measuring range of ±100 A (2.5 × IPN), it outputs a ratiometric analog voltage of 2.5 ± 0.8 V at nominal current . Accuracy is ±1% at 25°C and ±3.4% at 105°C, with ±0.5% linearity . Sensitivity is 8 mV/A. Response time is 2.5 µs and frequency bandwidth is DC to 250 kHz . Supply voltage range is 4.5 V to 5.5 V with a typical current consumption of 19 mA (max 25 mA) . Operating temperature ranges from -40°C to +105°C . Insulation test voltage is 4.3 kV RMS . The device is bidirectional and carries a 5-year LEM warranty .

LEM HO 40-NP-0100 Key Specifications

LEM HO 40-NP-0100 Key Advantages

The HO 40-NP-0100 employs open-loop Hall effect technology, delivering ±1% accuracy and ±0.5% linearity while providing galvanic isolation between primary and secondary circuits . The multi-range capability through primary layout configuration allows a single transducer to cover 10 A, 20 A, or 40 A nominal currents, simplifying inventory management . The ±100 A measuring range provides significant headroom for overload conditions (2.5 × IPN). The 250 kHz bandwidth and 2.5 µs response time capture dynamic current signals with high fidelity .

A key feature is the dedicated overcurrent detection output set at 2.93 × IPN on a separate open-drain pin, enabling fast system-level protection without additional circuitry . The VREF IN/OUT access provides system-level flexibility for reference voltage synchronization . The single +5 V supply simplifies integration into low-voltage digital systems . The through-hole PCB design offers low power consumption (19 mA typical, 25 mA maximum), high immunity to external interference, and no insertion losses . The device is factory calibrated with low offset and gain drift .

LEM HO 40-NP-0100 Typical Applications

AC variable speed drives and servo motor drives 
Static converters for DC motor drives 
Battery supplied applications
Uninterruptible Power Supplies (UPS) 
Switched Mode Power Supplies (SMPS)
Power supplies for welding applications 
Combiner box and MPPT systems 
Renewable energy systems 

Why Choose the LEM HO 40-NP-0100?

The HO 40-NP-0100 combines a 40 A rated current and ±100 A measuring range with ratiometric voltage output in a compact through-hole PCB-mount package with a single +5 V supply and overcurrent detection. Manufactured by LEM, it delivers stable, accurate, and safe current measurement for industrial applications requiring high-speed current sensing. The open-loop Hall effect design offers a cost-effective solution with multi-range flexibility, excellent interference immunity, and small footprint . The wide -40°C to +105°C operating