1. One – sentence Description
LF 205 – S is a precise current sensor that makes use of Hall effect closed – loop technology. It is specifically designed for the high – precision measurement of direct current, alternating current, and pulse current in industrial environments. It supports an ultra – wide measurement range of ±420A and has a high linearity accuracy of ±0.5%.
2. Core Features
- Closed – loop compensation architecture: A closed – loop design based on the Hall effect is adopted to eliminate hysteresis error and ensure long – term stability.
- Superb insulation performance: It can withstand an alternating current voltage of 3.5kV for 60 seconds, an impulse voltage of 8.8kV for 1.2/50μs, and the creepage distance is 11mm.
- Wide temperature range adaptability: The operating temperature ranges from – 40 to + 85℃, and the storage temperature ranges from – 40 to + 90℃. The temperature drift is controlled within ±0.4mA (- 40 to + 85℃).
- Electromagnetic compatibility protection: It has strong anti – interference ability and complies with the EN 50178/IEC 61010 – 1 standard.
- Compact package: It has a secondary winding impedance of 33Ω, supports M4 screw installation, and is small in size (78g).
3. Core Technical Indicators
| Category | Parameter | Typical Value/Range |
| Current Measurement | Rated Current (IPN) | ±200A (continuous) |
| Peak Current | ±420A (10s) | |
| Measurement Bandwidth | DC – 50kHz | |
| Accuracy | Total Error @25℃ | ±0.5% |
| Linearity Error | <0.1% | |
| Dynamic Response | Delay Time (10% – 90%) | <1μs |
| Power Consumption | Supply Voltage | ±12 – 15V (+5%) |
| No – load Current | 17mA | |
| Isolation Characteristics | Isolation Withstand Voltage | 3.5kVrms/60s |
| Creepage Distance | 11mm |
4. The Story Behind the Chip
LF 205 – S was born in the wave of demand for the intelligent upgrading of equipment in Industry 4.0. Facing the high standards for current detection in fields such as new energy and industrial automation, which require both the ability to withstand extreme working conditions (such as a transient current of up to 420A) and the achievement of sub – milliampere accuracy, LEM, relying on its 30 – year technical accumulation in the field of magnetic sensing, innovatively combined the zero – flux closed – loop technology with automotive – grade plastic packaging technology. Its core technology originates from the civil breakthrough of aerospace – grade magnetic modulation technology. Through the patented RMmin/RMmax dynamic resistance compensation algorithm, it solves the problem of temperature drift at high temperatures and has become a benchmark product in the industrial current detection field.
5. Design Philosophy
LF 205 – S follows the “three highs and two lows” design philosophy:
- High reliability: It has a UL 94 – V0 flame – retardant shell and can withstand an overload of 3 times the rated current.
- High precision: The bipolar latching calibration technology is used, and the temperature drift coefficient is only 0.12mA/℃.
- High bandwidth: A proprietary shielding layer design is used to suppress common – mode noise.
- Low power consumption: The power supply current is less than 17mA (including the signal conditioning circuit).
- Easy integration: It has a standard 3 – pin Molex interface and is compatible with PCB and rail installation.
6. Application Scenarios
- New energy field: MPPT tracking of photovoltaic inverters and monitoring of energy storage system battery packs.
- Industrial drive: Vector control of servo motors and power factor correction of frequency converters.
- Power protection: Current detection of UPS input and output and front – end sampling of harmonic analyzers.
- Special equipment: Arc current monitoring of welding power supplies and leakage current protection of medical equipment.
- Automotive electronics: Charging current metering of OBC in electric vehicles (customized version is required).
7. Unique Advantages
- Extreme dynamic performance: It has a response speed at the microsecond level, easily coping with high – frequency switching scenarios of IGBTs.
- Full – temperature – range stability: When TA = 85℃, it still maintains an accuracy of ±0.4%, which is 50% better than similar products.
- Dual safety certifications: It has passed both the IEC 61010 – 1 CAT III 600V and EN 50178 certifications.
- Flexible configuration: It supports a turn ratio adjustment of 1:2000 and is suitable for wires from 0.5mm² to 240mm².
- Anti – saturation design: It has a built – in magnetic balance mechanism to avoid data distortion caused by strong magnetic field interference.
8. What Engineers Must Know for Selection
- Key parameter chain: The rated current should be ≥1.5 times the load current, and the bandwidth should be 5 times higher than the system switching frequency.
- Thermal design points: The temperature rise under continuous current should be ≤30℃, and the heat dissipation area of the copper busbar needs to be calculated.
- Installation specifications: The primary aperture should be strictly aligned with the axis of the wire, and the eccentricity should be <0.5mm.
- Compatibility tips: When the power supply is ±15V, the ripple should be ensured to be <50mVpp, and it is recommended to use tantalum capacitors for filtering.
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Contact:
Sylvia Xu | ECSource Components Co.,Limited
Top 10 Test Laboratory Distributors in Asia.
D-U-N-S Number:655918890 | ISO90001 Certificated Company
Phone/Whatsapp: 0086-19806586673
Email:sylvia@ecsource.net
Line Card : FPGA, RF, MEMORY,CONNECTOR,Power