Current Sense Resistor Calculator

The optimal sense voltage is typically between 50mV and 200mV. Lower voltages minimize power loss but reduce signal-to-noise ratio, while higher voltages provide better accuracy but waste more power. 100mV is a common compromise.

Temperature affects resistor value through its temperature coefficient (TCR). Use precision resistors with low TCR (typically <100ppm/°C) for critical applications. The calculator considers temperature coefficient to estimate accuracy drift over your operating range.

Choose a power rating 2-10 times higher than the calculated dissipation to avoid overheating and ensure reliability. The calculator recommends a safety factor - use higher factors for critical applications or harsh environments.

Yes, parallel resistors can increase power handling capability, but they must be well-matched in value and temperature coefficient. The total resistance equals 1/(1/R1 + 1/R2 + ...) and power is distributed among them.

Use larger sense voltages when possible, add filtering capacitors across the sense resistor, use differential amplifiers, implement Kelvin connections for precision, and keep sense traces short and away from switching circuits.

Current sense resistors are precision devices with tight tolerances (±1% or better), low temperature coefficients, and often four-terminal Kelvin connections. They're designed specifically for measurement applications where accuracy is critical.

The voltage drop across the shunt resistor reduces available voltage for your load. Keep this under 1-2% of supply voltage for most applications. Higher drops waste power and may affect circuit regulation.

Current sense resistors are used in power supplies, battery management systems, motor controls, LED drivers, and anywhere precise current monitoring is needed for protection, regulation, or measurement purposes.