1. Introduction
In industrial automation systems, especially in power plants and petrochemical industries, the 4–20 mA current loop remains the most widely adopted standard for analog signal transmission. Compared with voltage signals (e.g., 0–10 V), the 4–20 mA signal offers superior noise immunity, long-distance transmission capability, and inherent safety, making it the preferred choice in harsh industrial environments.
In intrinsically safe (Ex) systems, the limited current level (4 to 20 mA) ensures that the energy transferred is not sufficient to generate sparks or arcs, which is critical in explosive atmospheres such as oil, gas, and coal-fired power plants.
2. Latest 4–20 mA Output Chips (2025 Edition)
2.1 GP8302 (China)
Digital-to-Analog Conversion via I²C: Enables easy integration with microcontrollers.
High Accuracy: Provides stable and precise current output.
Low Power Consumption: Suitable for energy-sensitive systems.
Strong EMC Design: Enhanced resistance to electromagnetic noise, ideal for power and petrochemical industries.
2.2 LTS111 (China)
High Integration: Combines signal conditioning, amplification, and current source.
Excellent Linearity: Ensures accurate conversion across the full measurement range.
Intrinsic Safety Design: Certified for hazardous areas, suitable for petrochemical and power plant environments.
2.3 XTR116 (Texas Instruments, USA)
Low Drift, High Accuracy: Well-proven for demanding control systems.
Wide Supply Voltage Range: Compatible with various industrial power conditions.
High Noise Immunity: Superior common-mode rejection (CMRR) ensures reliable operation in noisy environments.
Table 1 — Comparison of Common 4–20 mA Output Chips
| Parameter | GP8302 (China) | LTS111 (China) | XTR116 (TI, USA) |
|---|---|---|---|
| Accuracy | High | Very High | Very High |
| Power Consumption | Very Low | Low | Low |
| Integration Level | Medium | High | Medium |
| Intrinsic Safety Support | Yes | Yes | Limited |
| Temperature Stability | Good | Excellent | Excellent |
| Typical Applications | Power, OEM | Petrochemical, Precision Control | General Automation, DCS/PLC |
3. Selection Guidelines
When selecting a 4–20 mA output chip, engineers should carefully evaluate:
Accuracy and Linearity
Determines the reliability of measurement and control.
Higher accuracy ensures consistent process data.
Temperature Stability
Critical for power plants and outdoor installations with large thermal variations.
Noise Immunity
Strong EMC performance is essential for industrial environments with high electromagnetic interference.
Power Consumption and Supply Flexibility
Low-power designs extend system lifetime.
Chips supporting single- or dual-supply configurations simplify system design.
4. Conclusion
The 2025 generation of 4–20 mA output chips, including GP8302 and LTS111 from domestic manufacturers, and the well-established XTR116 from Texas Instruments, demonstrate significant improvements in accuracy, safety, and energy efficiency.
For hazardous environments, chips with intrinsic safety certification are recommended, while general automation applications can rely on mature and proven solutions like the XTR116.
By considering accuracy, stability, noise immunity, and power requirements, engineers can select the most suitable 4–20 mA output chip to ensure long-term system reliability and safety.