Two low-Ohmic resistor series protect even at high temperatures
PCIM 2021 Digital Days: Rohm Semiconductor has released the GMR320 and the PSR low-Ohmic resistors to provide accurate current protection even in high temperature applications
The GMR320 series series of shunt resistors are rated at 10W, and are the largest rated power product in the company's GMR portfolio, for high power applications in the automotive, industrial equipment and home appliances.
The resistors have a resistance value range from 5mΩ to 100mΩ, making them particularly suitable for automotive engine ECUs and headlamps as well as motors and power supplies for industrial equipment and home appliances. According to the company, the resistors reduce surface temperature rise by 23% over standard products, for rugged operation against over-current load despite being one of the smallest 10W class resistors in the market today. They are constructed with a high-performance metal alloy to provide low temperature co-efficient of resistance (TCR) for reliable current detection even in the low resistance values, says the company.
The resistors have been introduced in response to the demand for lower power consumption in high power applications in automotive and industrial projects. As a result, shunt resistors are required to support high power and high accuracy current detection to achieve high efficiency in a variety of applications.
The second series of resistors is the PSR series, which can be used used as a high power shunt resistor. Maximum rated power is 15W and the TCR value benefits from the use of the terminal temperature derating method. Resistance is particulartly low at just 0.1mΩ to 3.0mΩ, which is combined with high rated power and high current detection accuracy.
Both series are in mass production. Thermal simualtion modules for both the GMR320 and PSR series will be available from October. They will enable designers to reduce design time by performing simulations, even in high power applications.
Both series of shunt resistors are qualified to AEC-Q200 for automotive use. They have a maximum operating temperature of 170°C for reliable operation in the engine compartment.
At PCIM, Rohm hosted two online seminars - 'Integrated 1700V SiC MOSFET for Auxiliary Power Supply Solutions' at 11am on 4 May and 'Cost-saving in xEV with SMD resistors' at 11am on Wednesday 5 May.