Compliant Power Wirewound Resistors
9 September 2026 
Bourns has announced the UT-A Series, a new line of AEC-Q200 compliant high-temperature power wirewound resistors engineered for demanding automotive power systems. Spanning power ratings from 1 W to 10 W and resistance values from 10 Ω to 4.5 kΩ, the UT-A Series can give automotive power system designers a single, qualified family that scales from low-power signal conditioning to high-power load and braking circuits.
In automotive power systems, resistors routinely operate near engine bays, braking assemblies, and power conversion modules, where junction temperatures can exceed what standard industrial components are rated to handle. AEC-Q200 qualification provides design teams and their procurement organisations with a documented reliability baseline tied to those conditions—reducing qualification risk during PPAP and system validation. The UT-A Series’ extended operating range of −55 °C to 150 °C, combined with tight resistance tolerances, makes it directly applicable to powertrain and chassis subsystems where thermal margin and measurement accuracy both matter.
“Automotive power system designers need resistors that maintain their characteristics under sustained high-temperature loads, not just in brief transients. The UT-A Series is built for that environment—from the wirewound construction that supports long-term stability to the AEC-Q200 qualification that simplifies their compliance path.” — Walter Garcia, Product Line Manager Resistors at Bourns
Design Features and Key Capabilities
- Wide power and resistance ranges — power ratings from 1 W to 10 W and resistance values from 10 Ω to 4.5 kΩ support selection across multiple circuit requirements
- Tight resistance tolerance — options as low as ±1 % help minimise component variation and support stable, accurate circuit performance
- Low standard TCR — ±30 ppm/°C helps limit resistance variation as temperature changes
- High-temperature operation — specified for operation from −55 °C to 150 °C when used within the applicable power derating limits
- Excellent pulse handling — wirewound technology supports applications exposed to transient energy
- Durable construction — ceramic core, flame-resistant silicone coating, and all-welded terminations support long-term reliability
- AEC-Q200 compliant and RoHS compliant*
*RoHS Directive 2015/863, Mar 31, 2015 and Annex