Higher power chip resistors extend current sense range

TT Electronics has extended its MFC series of metal foil chip resistors with a new 2817 size that can dissipate up to 3W. Ideal for current sensing in the 1A to 30A range, the MFC2817 chip resistors enable designers to achieve highly compact power conversion circuits in demanding industrial and medical applications. In addition to power supply and DC-DC converters, these metal foil on ceramic resistors, also meet the current measurement requirements of driver circuits for motors, actuators, lighting and HVAC systems. This growing market for distributed power management and motion control faces pressure to reduce power loss whilst maintaining accuracy, leading to a demand for lower ohmic values and reduced TCRs. The device addresses this need with values from 3m to 150m and a low TCR of 30ppm/C compared to the 4m minimum value and 50ppm–100ppm TCR specification of the nearest competitive part. Metal foil on ceramic technology provides superior reliability compared to other resistor technologies: its surge tolerance is better than thick-film resistors ensuring improved reliability in the presence of current surges; and its self-heating is lower than thick-film or metal-strip types, which avoids hot-spots and further improves product reliability.