How to Select the Right Kelvin-Type Shunt Resistor for Your Power Module
Introduction
When designing power modules for industrial drives, renewable energy systems, or electric vehicles, accurate current sensing is critical for performance and safety. The Kelvin-Type Shunt Resistor—especially in SMT metal strip form—has become the preferred choice for engineers. But with multiple parameters to consider, how do you select the right one?
This guide will walk you through key selection criteria, the advantages of SMT metal strip design, and practical examples for different applications.
1. Key Parameters for Selection
a) Resistance Value (mΩ Range)
Low resistance (0.1–1 mΩ) → Ideal for high-current applications to minimize power loss.
Medium resistance (1–10 mΩ) → Balances measurement sensitivity and thermal performance.
High resistance (>10 mΩ) → Suitable for low-current precision measurement.
b) Power Rating
Match the resistor’s power dissipation capacity to your peak current and duty cycle.
Example: For a 100 A system with 1 mΩ, P=I2×R=10WP = I^2 \times R = 10 W.
c) Temperature Coefficient of Resistance (TCR)
Low TCR (<50 ppm/°C) ensures stable readings across temperature variations.
Essential in environments like EV traction systems or wind power converters.
d) Package & Mounting Style
SMT Metal Strip: Compact, low-profile, automated assembly ready.
Improves consistency and reduces assembly cost compared to through-hole designs.
2. Advantages of SMT Metal Strip Kelvin-Type Shunt Resistors
Four-terminal Kelvin connection eliminates lead resistance errors, enabling high-precision current measurement.
Automated PCB mounting reduces manual soldering, improves production efficiency.
Low thermal EMF ensures accuracy in bidirectional current measurement.
Robust construction handles high surge currents without degradation.
| Power Module Type | Recommended Resistance | Power Rating | Notes |
|---|---|---|---|
| EV Motor Drive (200–400 A) | 0.2–0.5 mΩ | 20–50 W | High surge handling required |
| Industrial Servo Drive (50–150 A) | 0.5–1 mΩ | 5–15 W | Low TCR for stability |
| Solar Inverter (20–80 A) | 1–5 mΩ | 2–10 W | Focus on measurement sensitivity |
| Battery Management System (BMS) | 1–10 mΩ | 1–5 W | Compact SMT size preferred |
4. Quick Selection Checklist
Before ordering your Kelvin-Type Shunt Resistor, confirm:
Required resistance value in mΩ.
Maximum continuous & peak current.
Power rating margin (at least 25% above expected).
TCR suitable for your operating temperature range.
Package type (SMT metal strip for automation, others for custom).
Conclusion & CTA
Choosing the right Kelvin-Type Shunt Resistor ensures your power module delivers reliable, accurate current sensing without performance drift. At https://ohmresistor.com, we offer customized SMT metal strip resistors with low TCR, tight tolerance, and proven durability for demanding industrial and automotive applications.
