Schottky Barrier Rectifier Trench Schottky Barrier Type Switching Mode Power Supply Applications Portable Equipment Battery Applications# Technical Documentation: CRS03 Current Sensor
## 1. Application Scenarios
### 1.1 Typical Use Cases
The CRS03 is a non-contact current sensor utilizing Hall-effect technology, making it suitable for applications requiring isolated current measurement without direct electrical contact with the conductor.
Primary applications include:
- Motor control systems : Monitoring phase currents in BLDC, PMSM, and AC induction motors for precise torque control and overload protection
- Power supply monitoring : Measuring input/output currents in switched-mode power supplies (SMPS), UPS systems, and DC-DC converters
- Battery management systems (BMS) : Current monitoring for charge/discharge control, state-of-charge estimation, and protection circuits
- Renewable energy systems : Solar inverter current sensing and wind turbine generator monitoring
- Industrial automation : Load monitoring for predictive maintenance and process control
### 1.2 Industry Applications
Automotive Industry:
- Electric vehicle traction motor current sensing
- Battery current monitoring in hybrid/electric vehicles
- 48V mild-hybrid system monitoring
- On-board charger current measurement
Industrial Equipment:
- Variable frequency drives (VFDs) for industrial motors
- Welding equipment current control
- Uninterruptible power supplies (UPS)
- Industrial robot joint motor monitoring
Consumer Electronics:
- High-power audio amplifier protection circuits
- Server power supply monitoring
- Appliance motor control (air conditioners, refrigerators)
Energy Sector:
- Solar microinverters
- Energy storage system monitoring
- Smart meter current sensing
### 1.3 Practical Advantages and Limitations
Advantages:
- Galvanic isolation : Eliminates need for shunt resistors and provides inherent isolation between measured circuit and sensing circuit
- Low power loss : Minimal insertion loss compared to shunt resistors
- Wide bandwidth : Typically 100kHz+ bandwidth suitable for switching power applications
- Bidirectional current measurement : Capable of measuring both positive and negative currents
- High linearity : Excellent linear response across operating range
- Temperature stability : Built-in temperature compensation circuits
Limitations:
- Magnetic interference susceptibility : External magnetic fields can affect accuracy
- DC offset drift : May exhibit temperature-dependent offset voltage drift
- Saturation effects : Magnetic core can saturate at very high currents
- Limited accuracy : Typically 1-3% accuracy, less precise than high-end shunt-based solutions
- Size constraints : Larger than shunt resistors for equivalent current ratings
## 2. Design Considerations
### 2.1 Common Design Pitfalls and Solutions
Pitfall 1: Magnetic Interference
- Problem : External magnetic fields from nearby transformers, inductors, or high-current traces can induce measurement errors
- Solution :
- Maintain minimum 10mm clearance from magnetic components
- Use magnetic shielding if necessary
- Orient sensor perpendicular to potential interference sources
Pitfall 2: Thermal Drift
- Problem : Output voltage drift with temperature changes
- Solution :
- Implement software temperature compensation using onboard temperature sensor (if available)
- Ensure adequate thermal management with proper PCB copper pours
- Use temperature-stable reference voltages
Pitfall 3: High-Frequency Noise
- Problem : Switching noise from power electronics contaminating sensor output
- Solution :
- Implement RC filtering at output pin (typically 1-10nF capacitor)
- Use differential measurement techniques
- Separate analog and power grounds
Pitfall 4: Core Saturation
- Problem : Sensor output becomes non-linear at current extremes
- Solution :
- Select sensor with appropriate current range (derate by 20-30%)
- Implement software clipping algorithms
- Use current
