Power Resistor UT - wirewound

Wirewound power resistor for high temperatures and precise current and voltage control

The UT series power resistors are designed for applications where high operating temperatures, very good pulse handling and precise characteristics are required. The resistance wire is embedded in a high-temperature resistant encapsulation, allowing the resistor to operate reliably in harsh environments – from industrial electronics to automotive applications.

With up to 10 W @ 25 °C without heatsink and a resistance range from 0.01 Ω to 260 kΩ, the UT series covers typical tasks from low-ohmic current-sense and load functions to reference and control resistors in the higher kΩ range. Resistance tolerances from ±0.01% to ±10% support both high-precision and cost-optimised designs. The temperature coefficient ranges from ±20 ppm/°C to ±90 ppm/°C, depending on the resistance value, so the resistance drift over the specified temperature range remains moderate.

A key feature of the series is the extended temperature capability: the standard version operates from −55 °C to +275 °C, while the HT version is specified up to +350 °C. Combined with the good pulse performance, this makes the UT particularly suitable for current and voltage regulators, power and charge management, renewable energy systems and automotive control and power modules, where resistors are exposed to elevated temperatures over long periods.

Optional non-inductive windings reduce parasitic inductance and facilitate use in fast or switching power stages. The option of a 4-wire Kelvin connection enables precise current and voltage measurement directly at the resistor, without lead resistance influence – an advantage in high-accuracy control loops and measurement paths.

Options

• Resistance range: 0.01 Ω–260 kΩ with freely selectable values (in xxxkxxx format (e.g. 10k000, 10k100)
• Resistance tolerances: ±0.01%, ±0.02%, ±0.05%, ±0.1%, ±0.25%, ±0.5%, ±1%, ±2%, ±5%, ±10% (depending on value)
• Temperature coefficients: TCR classes from ±20 ppm/°C to ±90 ppm/°C, depending on resistance value
• HT version: extended operating temperature range up to +350 °C
• Non-inductive winding for applications with fast current and voltage pulses (option)
• 4-wire (Kelvin) connection for precise current and voltage measurement directly at the resistor (option)