Technical Analysis of CTSR 1-P High-Precision Current Sensor
1. One-Sentence Description
The CTSR 1-P is a closed-loop compensated current sensor for industrial and energy sectors, supporting high-precision measurement of DC, AC, and pulse currents with electrical isolation.
2. Core Features
- Closed-loop compensation technology: Achieves high linearity and low temperature drift via flux balance principle.
- Voltage output interface: Directly outputs voltage signal (0–5 V) proportional to measured current.
- Single-supply operation: Works within 4.75–5.25 V voltage range, compatible with standard electronic systems.
- Compact package: UL 94-V0 flame-retardant plastic housing with 20.1 mm aperture for large-current conductors.
- Dual safety certification: Compliant with IEC 61010-1 and UL 508 standards, supporting 600 VAC/DC withstand voltage test.
- Flexible reference mode: Supports internal reference (2.5 V) and external reference (2.3–4 V) inputs.
3. Core Technical Specifications
| Category | Parameter | Typical Value | Limit Value |
|---|---|---|---|
| Accuracy | Linearity Error | 0.5% | 1% |
| Temperature Coefficient (Sensitivity) | ±200 ppm/°C | - | |
| Dynamic Performance | Bandwidth (-1 dB) | 9.5 kHz | - |
| Response Time (10%–90%) | 7–50 μs | - | |
| Insulation Capability | Creepage Distance/Clearance | 11 mm | - |
| Rated Withstand Voltage | 10.1 kV (Impulse) | 5.4 kV (Power Frequency) | |
| Environmental Adaptability | Operating Temperature | -40–105°C | - |
4. The Story Behind the Chip
The CTSR 1-P is designed to meet the demand for high-precision and reliable current detection in industrial scenarios. Its closed-loop architecture addresses temperature drift in traditional open-loop sensors by real-time magnetic flux compensation. The UL 94-V0 flame-retardant housing and dual-insulation design are optimized for complex electromagnetic environments and high-voltage risks in new energy applications (e.g., photovoltaic inverters).
5. Design Philosophy
- Safety-first: Strictly follows IEC 61010-1 safety standards to minimize electric shock risks.
- Anti-interference capability: Built-in low-pass filter (470 Ω/22 nF) suppresses noise, supporting up to 10 kHz signal acquisition.
- Easy integration: PCB package compatible with standard wave soldering, pin pitch design simplifies assembly.
6. Application Scenarios
- New energy field: Leakage current detection in photovoltaic inverters, symmetrical fault diagnosis in energy storage systems.
- Industrial automation: Overcurrent protection for motor drives, three-phase current balance monitoring.
- Medical equipment: Residual current monitoring in patient contact protection circuits.
- Laboratory testing: Pulse current calibration and transient response analysis.
7. Unique Advantages
- Wide range adaptability: Single measurement covers ±30 A DC/AC current without range switching.
- Dual degaussing mechanism: Auto-power-on degaussing + manual trigger mode (via U_ref pin) ensures zero-point stability.
- High overload capability: Withstands 3300 A peak current (100 μs duration) to avoid transient damage.
8. Key Considerations for Engineers in Selection
- Installation constraints: Primary conductor should maintain ≥30 mm spacing to avoid adjacent component interference.
- Thermal management: Housing temperature must not exceed 110°C; heat sinks are recommended.
- Reference voltage configuration: External reference (U_ref) requires impedance matching (typically 499 Ω) to prevent current overload.
- Certification compliance: Final products must pass EMC testing; LEM disclaims liability for unstated scenarios.
Conclusion
The CTSR 1-P serves as a core device for reliable current detection, thanks to its closed-loop accuracy, wide-temperature stability, and industrial-grade protection. Engineers should prioritize installation specifications and reference circuit design to fully leverage its performance.
