CTSR 0.3-P Precision Current Sensor: Industrial-Grade High-Accuracy Isolated Detection Solution

1. One-Sentence Description

The CTSR 0.3-P is a precision current transformer using closed-loop compensation technology, specially designed for high-isolation measurement of direct current (DC), alternating current (AC), and pulse currents, suitable for precise current detection in industrial and new energy fields.

2. Core Features

• Closed-loop compensation architecture: Achieves high linearity and low distortion through flux balance.
• Voltage output interface: Directly outputs a voltage signal proportional to the current (0–7 V) without additional amplifying circuits.
• Single-power-supply operation: Compatible with 5 V DC power supply, wide voltage range (4.75–5.25 V).
• PCB surface mount design: Miniaturized package supporting surface mount technology.
• Multiple safety certifications: Compliant with IEC 61010, UL 508, etc., supporting SELV safety circuits.

3. Core Technical Specifications

4. The Story Behind the Chip

The CTSR series was born out of the urgent need for high-precision current detection in new energy and industrial automation. Traditional current transformers suffer from insufficient frequency response and significant temperature drift, while the CTSR 0.3-P reduces non-linear error to 0.5% through innovative full closed-loop compensation technology and supports a bandwidth of up to 3.5 kHz, making it a core component in scenarios such as photovoltaic inverters and battery management systems. Its design integrates electromagnetic isolation with digital calibration algorithms, balancing performance and reliability.

5. Design Philosophy

• Minimalist isolation architecture: Achieves electrical isolation between primary and secondary circuits through magnetic coupling, with a withstand voltage rating of 5.4 kV RMS (power frequency withstand voltage).
• Low-power optimization: Operating current is only 17.5–21.6 mA, reducing system energy consumption.
• Enhanced anti-interference: Built-in decoupling capacitors and filter circuits suppress high-frequency noise (e.g., interference above 100 kHz is attenuated by >40 dB).
• Flexible configuration: Supports external reference voltage input (2.3–4 V) to adapt to different range requirements.

6. Application Scenarios

• Photovoltaic field: Leakage current monitoring and residual current protection for transformerless inverters.
• Power supply systems: Fault detection and symmetrical fault analysis for chargers/adapters.
• Industrial control: Overcurrent protection for motor drives, current sharing monitoring for stacked DC power supplies.
• New energy vehicles: Insulation detection for charging piles, thermal runaway early warning for battery packs.

7. Unique Advantages

• Ultra-low temperature coefficient: Offset voltage temperature drift is only ±570 ppm/°C (typical value), suitable for wide temperature environments.
• High overload capability: Can withstand 3300 A peak current (100 μs pulse) to avoid transient damage.
• Dual safety modes: Supports Degauss and Test functions to simplify the debugging process.
• Compact package: Dimensions of only 12 mm×24 mm, suitable for high-density PCB layouts.

8. Key Considerations for Engineers in Selection

• Rated current matching: Ensure the measured current does not exceed ±300 mA (overload may cause accuracy degradation).
• Output impedance limitation: Load resistance must be >500 kΩ, otherwise bandwidth and linearity will be affected.
• Installation spacing: Maintain a spacing of ≥30 mm between primary terminals and other components to prevent magnetic coupling interference.
• Safety specifications: Must be used in SELV circuits, with a creepage distance of ≥11 mm on the housing (complying with EN 50178).
• Calibration recommendations: Perform degaussing before first use and verify zero offset (typical value ±24 mA).

Conclusion

The CTSR 0.3-P has become a benchmark product in the high-precision current detection field with its extreme accuracy, reliability, and flexibility. Its core technology solves the temperature drift and bandwidth bottlenecks of traditional solutions, making it particularly suitable for industrial and new energy scenarios with strict requirements for safety and stability.