USR 4-1414 is a precision resistor produced by Willow Technologies, with the highest stability, near temperature independency, lowest tolerances, low capacitance and inductance, and customized resistance values.
The USR 4-1414 is a precision resistor offered by Willow Technologies. The sheet lists its electrical characteristics such as resistance range, power rating, tolerance options, temperature coefficient and voltage proof. It also provides environmental and mechanical details including substrate, housing, connector material and dimensions.
Additional information includes derating curves for operation with and without a heatsink, thermal EMF values, and ordering codes. Contact details for Willow Technologies are provided for further inquiries or custom resistance values.
| Power rating (no heatsink) | 0.8 W at 70 °C |
|---|---|
| Power rating (with heatsink) | 25 W |
| Tolerance options | 0.1 % – 1 % |
| Temperature coefficient (typical) | +3 ppm/K (-55…125 °C) |
| Maximum temperature coefficient | ±5 ppm/K (-55…155 °C) |
| Maximum voltage rating | 1.5 kV DC |
| Thermal EMF | <1 µV/°K |
| Resistor material | NiCr foil |
| Substrate | Aluminum oxide (optional AIN) |
| Housing | Plastic + epoxy |
| Connector material | Cu‑tinned, 4‑pin |
| Dimensions | 14.0 mm × 40.0 mm × 6.3 mm |
| Derating (power) | 400 W without heatsink, 120 W with heatsink |
It is rated at 0.8 W when operated at 70 °C without a heatsink.
The resistor is offered in tolerances of 0.1 %, 0.25 %, 0.5 % and 1 %.
It can handle up to 1.5 kV DC.