Current sensing stages keep getting pushed harder as automotive and industrial systems move toward higher power densities and tighter thermal envelopes. Designers often need resistors that handle more heat while still delivering low drift and long term reliability. ROHM’s new UCR10C shunt resistor family is built around that challenge, offering a 2012 size device rated for power levels normally reserved for wider terminal or larger format components.
A Small Footprint With Power Handling Normally Found in Larger Packages
The UCR10C series uses a copper based resistive element formed on an alumina substrate through a sintering process. This choice of structure gives the part a thermal path that supports 1.0W and 1.25W ratings in the same footprint where many existing thick film or metal plate resistors operate at roughly half that level. In practice this lets engineers drop component count or replace oversized parts without compromising temperature rise or derating margins. For compact power stages or densely packed automotive modules, that reduction in board area can help ease mechanical constraints without altering current measurement accuracy.
The construction avoids the need to move to wide terminal styles simply to gain extra heat dissipation. This is particularly relevant when PCB layouts already have fixed pad geometries or when switching to a larger resistor would disrupt trace routing, creepage distances or sensing accuracy.
Stability Over Temperature for Precision Current Measurement
The series achieves a low temperature coefficient of resistance ranging from 0 to +60 ppm per degree Celsius depending on value. For current sensing, this limits measurement drift when ambient or junction temperatures rise, keeping control loops predictable. In systems such as motor drives, battery management and industrial power supplies, maintaining accuracy under fluctuating temperatures reduces the amount of software compensation needed to stabilise readings.
Durability testing matches the performance level more commonly associated with metal plate devices. The parts withstand 1000 temperature cycles between minus fifty five and one hundred fifty five degrees Celsius, which demonstrates bonding reliability when exposed to the thermal swings seen in automotive power domains and industrial enclosures over long deployment periods.
Material and Environmental Considerations
ROHM specifies the UCR10C as fully lead free, including areas that fall under optional RoHS exemptions. For manufacturers aligning with long life sustainability targets or preparing for tightening environmental requirements, this simplifies compliance without needing to requalify multiple resistor variants across different regions.
Roadmap and System Level Use Cases
The company also plans a 3216 2W version under the UCR18C name, which expands the same sintered metal approach into larger packages for higher power systems. For engineers working across multiple platforms, having a family of resistors that share similar thermal behaviour and drift characteristics helps create consistent current measurement performance across product lines.
Applications likely to benefit include traction inverters where shunts operate near hot switching devices, industrial drivers that demand low drift under continuous cycling and consumer designs that require dependable current measurement in tight enclosures. The design emphasis on long term stability and efficient thermal performance aligns with the broader movement toward high precision sensing in electrically dense systems.
Learn more and read the original announcement at www.rohm.com
You may also like
