TT Electronics OAR Current Sense Resistors
TT Electronics Open Air Resistor (OAR) Current Sense Resistors provide current sensing with a metal element design that supports surge current handling while limiting heat transfer to the circuit board. The open air wirewound construction separates the resistor hotspot from the PCB, while tight pitch versions are available for alternative mounting requirements. The OAR series offers 1W, 3W, and 5W power ratings at 85°C, resistance values from 2.5mΩ to 100mΩ depending on the model, and tolerances down to ±1%. These resistors are available in lead-free options compliant with the specified EU RoHS directive. OAR resistors operate within a temperature range from -40°C to +125°C and find applications in current sensing and motor controllers.
Features
- Hotspot isolated from the PCB
- Low TCR resistance wire
- Pb-free
- Surge current capability
- Tight pitch option
Applications
- Body computers
- Current sensing
- Feedback and surge protection circuits in ABS systems
- Heated seats
- Motor controllers
- Power steering systems
- Window lift and sunroof motors
- Wiper controls
Technical Specifications
| Parameters | Values | |
|---|---|---|
| Resistance Tolerance | ±1%, ±2%, and ±5% | |
| Inductance | <10nH | |
| Operating Temperature Range | -40°C to +125°C | |
| Power Ratings at 85°C | 1W, 3W, and 5W | |
| Resistance Range | OAR1 | 3mΩ to 100mΩ |
| OAR3 | 2.5mΩ to 100mΩ | |
| OAR5 | 3mΩ to 50mΩ | |
