SMD Resistor MSI - wirewound

Robust SMD wirewound resistor for current sensing, shunt applications and high continuous temperatures

The SMD wirewound resistors of the MSI series are designed for applications that require high continuous load capability, very low resistance values and a wide operating temperature range. Depending on the type, the resistors offer rated powers of 0.5 W, 1 W, 2 W or 4 W at 70 °C and can be used in an extended operating temperature range from −55 °C to +275 °C. The epoxy-moulded package is flame-retardant in accordance with UL94 V-0 and provides reliable protection of the resistive element against mechanical and environmental influences.

With a resistance range from 0.005 Ω to 50 kΩ, the MSI series covers both very low-ohmic shunt and current-sensing resistors and higher values for power and control circuits. Different power versions allow a suitable balance between package size and load capability. Resistance tolerances from ±0.05% up to ±5% support both simple power applications and more demanding measurement and control tasks. The temperature coefficient from ±20 ppm/°C (for R > 10 Ω, typically ±50 ppm/°C in the low-ohmic range 1–10 Ω) ensures that the resistance value changes only moderately across the specified temperature range.

Wirewound technology inherently offers high robustness against continuous load and short-term overload. In addition, the MSI series is optionally available with non-inductive winding, which is particularly useful for current-sensing and shunt applications in circuits with steep current edges – for example in switched-mode power supplies or drive and power electronics, where parasitic inductance can cause measurement errors or overshoot.

Typical qualification tests such as dielectric withstand, load life, storage, humidity resistance, thermal shock, overload, mechanical shock and solderability are specified for the series. This ensures that MSI resistors maintain stable characteristics even under harsh operating conditions, making them a good choice wherever currents must be measured accurately and high power levels safely handled over long periods.

Options

• Power ratings: 0.5 W, 1 W, 2 W and 4 W at 70 °C (types MSI-1, MSI-2, MSI-4, MSI-5)
• Resistance range: 0.005 Ω–50 kΩ, with resistance ranges depending on the power rating
• Resistance tolerances: ±5%, ±1%, ±0.5%, ±0.25%, ±0.05% (depending on resistance value)
• Temperature coefficients: ±20 ppm/°C (R > 10 Ω), ±50 ppm/°C (R = 1–10 Ω)
• Custom resistance values within the specified range, including finely stepped values (in xxkxxx format e.g. 10k100)
• Non-inductive winding option for defined resistance ranges (min. 0.1 Ω, depending on the maximum value of the series)
• Supplied either on tape-on-reel or in bulk to support different assembly and logistics concepts