Riedon, a specialist manufacturer of resistive solutions, is looking to target the demanding requirements of current sensing and shunt applications with its comprehensive portfolio of low ohmic value resistors, ranging from the economical bare metal element MSR series through to its CLSA series chip resistors that provide AEC-Q200 compliance for use in harsh automotive environments.
By employing various technologies, Riedon is able to offer ±1% tolerance resistances from 0.5 milliohms up to 1 ohm in various package formats with TCRs as low as ±20ppm/oC and power ratings up to 5 Watts. For tolerances down to ±0.1%, Riedon is also able to supply four terminal versions of its axial lead low ohm power resistor.
The company’s MSR series uses a bare metal element in an all-welded construction for through-hole circuit board mounting to provide resistance values from 5mO to 100mO, while also achieving low inductance (<10nH) and low TCR (±20ppm/oC). MSR resistors are available in 1, 3 and 5-Watt power ratings with tolerances of ±1% or ±5%. For surface mount applications a number of chip resistor solutions are available: MNRS chip shunt resistors offer long-term stability and low inductance with 4- and 6-Watt ratings and resistances from 1mO to 4mO; the CSR family of ultra low ohm metal strip chip resistors come in three sizes (1206 / 2010 / 2512) for power ratings from 1 to 3 Watts, with standard and customised resistance values from 0.5 mO to 15mO; and featuring an alumina substrate for high power dissipation the CLS/CLSA series of chip resistors operate over -55oC to +155oC, with the CLSA parts meeting the Automotive Engineering Council’s AEC-Q200 stress test qualification.
“Current sensing applications insert a low ohmic precision resistor in series with the load current, creating a small voltage drop that can be readily measured and used to calculate the current flowing through the resistor”, explains Phil Ebbert, Riedon’s VP of Engineering, “Resistance values of just a few milliohms allow currents of several Amps, even tens of Amps, to be handled with device power ratings up to 5 Watts.”