Linear Technology announces the LS8 reference family, a series of hermetic precision-voltage references packaged in a 5 mm x 5 mm surface-mount, low-stress ceramic package. These precision-voltage references offer outstanding long-term stability and consistent predictable behavior over time and operating conditions. For instrumentation that demands the best possible performance over years or decades of operation, the LS8 package offers an alternative to large metal can or ceramic DIP packages. Mechanical stress on the internal die of a voltage reference frequently causes a shift in its output voltage. The LS8 package achieves superior stability, minimizing die stress in a number of ways. First, the LS8 is a hermetic package, which eliminates humidity effects. This significant and often unrecognized source of error is due to the absorption of water in non-hermetic plastic packaging. Typically, non-hermetic parts can experience 150 ppm or more of error with 25% changes in relative humidity. In addition, the LS8 package has minimal direct die contact, reducing die stress from the package. In contrast, plastic molding applies stress directly to a silicon die over time and temperature. Because silicon and plastic have different thermal coefficients of expansion, temperature cycling a plastic part will apply inelastic stress to the die. The result is residual error, even when the part returns to 25°C. Similarly, a large component of long-term drift error is due to the plastic package settling over time. All of this is significantly reduced in the LS8 reference family. “The LS8 package is a break-through for voltage references,” said Brendan Whelan, design manager for Linear Technology.