Vishay Intertechnology, Inc. has released four technical notes at its Web site that provide designers with detailed studies about the benefits of its foil resistors.
Here’s the line-up:
“Non-Linearity of Resistance Temperature Characteristic: Its Influence on Performance of Precision Resistors” shows how and why Vishay’s Z-Foil resistors exhibit the lowest temperature coefficient of resistance (TCR) over a wide range of temperatures and the smallest nonlinearity of the delta R/R = f(T) curve. The technical note demonstrates how Z-Foil’s low TCR over a wide temperature range also leads to a reduction of resistance change due to the Joule effect reducing the thermal stabilization time regardless of ambient temperature and load.
“ESD Sensitivity of Precision Chip Resistors: Comparison Between Foil and Thin Film Chips” uses test data to show that foil resistor technologies achieve two orders of magnitude superior stability over thin-film chips when subjected to high-voltage electrostatic discharge (ESD). This superiority results mainly from a lower temperature rise, a benefit of the much larger thickness and therefore heat capacity of the resistive foil layer compared to thin films, said Vishay.
“Prediction of Drift in Foil Resistors” presents a method for predicting foil resistor behavior under various load conditions and service times, which can help design engineers to select the best foil resistor for various high-precision applications. The method allows the maximum value of the drift to be calculated for any combination of load, service time, and required confidence level.
“Pulse Load Capability of Precision Chip Resistors” reports on a series of tests that were performed on precision foil and thin-film chip resistors to determine the effect of different pulse types on the devices’ stability and precision. The results show that for pulse durations down to 1 ms, the foil and the thin-film chips perform similarly, but for shorter pulses the foil chips show a very substantial advantage over thin-film chips.
Click here for more information about Vishay Bulk Metal Foil resistors.