LT505-S/SP11,LT 505-S/SP11

LT505-S/SP11 Hall-Effect Closed-Loop Current Transducer – Built for Demanding Industrial Applications

LT505-S/SP11 One-Sentence Core Value Proposition

Closed-loop fluxgate architecture, ±0.5% accuracy, 500A high-precision current measurement – when your inverter falsely trips overcurrent at 300A continuous load, what you truly need is the physical-level closed-loop compensation of the LT505-S/SP11, not a software null shift.

LT505-S/SP11 Industry Pain Points: Are You Troubled by These Issues?

In industrial automation, rail traction systems, or high-power converters, a ±0.7% measurement error can cause protection nuisance trips, bringing an entire production line to a halt. Conventional open-loop Hall sensors rely on magnetic sensing elements to directly measure flux density; the non-linearity of ferrite cores and the temperature coefficient of Hall elements (typically ±300 ppm/°C) introduce systematic errors. When your DC-DC module falsely reports overcurrent under harsh conditions, or your PV inverter exhibits protection jitter during bus current transients – the culprit is often not the load, but the zero-point drift of the current sensor.

The LT505-S/SP11 is designed precisely to solve these industrial “pain points”.

LT505-S/SP11 Key Performance Advantages

Closed-Loop Fluxgate Architecture – Unmatched Accuracy vs. Open-Loop Solutions

The LT505-S/SP11 employs a closed-loop Halleffect current transducer technology that provides complete galvanic isolation between the primary (high-power) circuit and the secondary (electronic) circuit. Its two-stage fluxgate compensation technology works by exactly nullifying the magnetic flux generated by the primary current with an opposing flux from a secondary compensation winding, keeping the magnetic core at zero flux. Under this condition, the compensation current is strictly proportional to the primary current, with the ratio determined solely by coil turns and ASIC voltage reference stability – not by the intrinsic properties of the Hall element.

Rated measuring current: 500 A

Maximum measuring range: up to 1400 A (overload capability)

Accuracy: ±0.5% to ±0.6%

Linearity: ±0.1% – the output voltage maintains excellent linearity with the measured current across the full range

Unrivalled Temperature Stability

The LT505-S/SP11 uses a low-temperaturedrift ferrite core (TCr < 5 ppm/°C) together with a dual temperature-compensation resistor network, suppressing the temperature drift of the ASIC reference voltage to just ±5 µV/°C. The symmetrical dual-winding structure of the compensation coil cancels any thermal-stress-induced core distortion. Over the wide temperature range of -40°C to +85°C, the zero-point offset drift is measured at only 0.18 ± 0.05 mA (for the 500 A range).

In a DC-DC module’s current loop, a 0.2 mA offset can cause a 5% feedback error – enough to induce oscillation. The LT505-S/SP11 ensures your system remains stable under extreme temperature variations.

Extreme Response Speed – Capture Every Current Spike

Response time: only 1 µs, capturing transient current changes with lightning speed

Frequency bandwidth: DC to 150 kHz, covering AC, DC, and pulsed current signals

Bidirectional measurement: supports both positive and negative currents

In a 250 kW PV inverter test with a bus current slew rate di/dt > 10⁶ A/s, the LT505-S output showed no overshoot and remained stable. For IGBT turnoff overcurrent protection, a 1 µs response time means there is enough time to take protective action before a fault develops.

Powerful Electromagnetic Interference Rejection

In a rail traction inverter environment with high-frequency PWM noise, the LT505-S/SP11 achieves a commonmode rejection ratio of 85 dB @ 50 kHz. Its shielded housing and core-embedded Faraday cage effectively block external magnetic field coupling, ensuring that measurements remain accurate even in complex electromagnetic environments. The insulating plastic housing complies with UL 94-V0 flammability standards for comprehensive system safety.

Flexible Power Supply and Output Options

Supply voltage: ±15 V to ±24 V bipolar

Power consumption: max. supply current 30 mA – low-power design saves system energy

Output voltage/current: supports multiple output formats, direct connection to PLCs or other programmable controllers

LT505-S/SP11 Rich Application Scenarios

With its high accuracy, high reliability, and wide operating range, the LT505S/SP11 is widely used across many industrial fields:

LEM transducers can measure instantaneous current and voltage values in galvanically isolated mode, offering contactless, multi-conductor, and clamp-on measurement options. Current measurement ranges from 0.1 A up to 20,000 A, and voltage ranges from 10 V to 12,000 V.

Why Choose the LEM LT505-S/SP11?

LEM is a world leader in electrical measurement transducers, headquartered in Switzerland with over 50 years of R&D and manufacturing experience. Its closed-loop Hall-effect technology is trusted in rail systems, industrial automation, and energy installations worldwide. LEM uses advanced manufacturing processes with multiple adjustments and calibrations during production to ensure every transducer meets the performance and quality required by the market.

Xi’an Haonan Electronic Technology Co., Ltd., an authorised distributor of LEM products, provides genuine stock, professional technical support, and complete after-sales service.

LT505-S/SP11 Technical Specifications at a Glance

The above parameters are based on the LT505S series standard specifications. For exact parameters of the SP11 variant, please contact our sales team.

LT505-S/SP11 Advantages at a Glance

Closed-loop fluxgate architecture – zeroflux precise compensation, accuracy independent of Hall element characteristics

High accuracy ±0.5% – linearity better than 0.15% across the 100 A to 500 A range

Excellent temperature drift suppression – stable operation from -40°C to +85°C

1 µs ultra-fast response – precisely captures transient current spikes for faster overcurrent protection

Strong EMI rejection – 85 dB @ 50 kHz CMRR, shielded housing + Faraday cage structure