Precision Resistor UMX - metal film

Metal film precision resistor with low TCR for demanding signal paths

The UMX precision resistors are designed as general-purpose metal film precision resistors for accurate analogue and measurement circuits. The thin metal film on a ceramic substrate and the epoxy-moulded housing provide stable characteristics and low noise, making the UMX suitable for temperature and data acquisition, test and measurement electronics, precision op-amp stages and high-quality audio circuits. Its low-inductance and virtually capacitance-free design reduces parasitic effects in fast or wideband signal paths.

The resistance range from 10 Ω to 1 MΩ covers typical tasks from current sense paths and voltage dividers to reference networks. Resistance tolerances from ±0.05% to ±0.2% allow precise dimensioning without complex trimming. The temperature coefficient ranges from ±5 ppm/°C to ±25 ppm/°C depending on version, with particularly low TCR values offered in the core range. The series includes two power classes: UMX30 with 0.25 W and UMX50 with 0.5 W at 70 °C. Maximum working voltages are 350 V and 500 V, respectively, with an operating temperature range from −55 °C to +125 °C.

Tests such as load life at rated power, damp heat, temperature cycling, resistance to soldering heat and dielectric strength are specified in the datasheet and limit permissible resistance changes to small values. This makes the UMX suitable for long-term operated measurement, control and signal conditioning circuits where temperature drift, parasitic inductance and additional capacitance must be kept as low as possible.

Options

• Types: UMX30 (0.25 W) and UMX50 (0.5 W), both with 5.08 mm lead spacing
• Resistance range: 10 Ω–1 MΩ, depending on type, with finely stepped values in standard notation (e.g. 10k000, 10k200)
• Resistance tolerances: ±0.2%, ±0.1%, ±0.05% (depending on resistance value)
• Temperature coefficients: TK classes ±5 ppm/°C, ±10 ppm/°C, ±15 ppm/°C and ±25 ppm/°C depending on resistance value
• Radial, tinned brass leads for THT assembly