Vishay extends its high-precision thin film surface-mount wraparound chip resistor array offering with new PRA series devices in compact 073 and 074 case sizes. Without compromising precision or reliability, the new PRA073 and PRA074 resistor arrays save board space and replace more expensive matched resistors in instrumentation, calibration, and data conversion systems in aircraft engine controls and flight command computers; precision scales; automatic test equipment; and medical applications.
The new thin film chip resistor arrays are the industry's smallest such devices available with up to eight resistors of different ohmic values, tight tolerance ratios down to 0.01 %, and TCR tracking to 1 ppm/°C.
The PRA073 and PRA074 feature: dimensions of 1.4mm x 0.75 mm x 0.7 mm and 1.4 mm x 1 mm x 0.7 mm, respectively; ohmic ranges of 10 Ω to 50 KΩ and 10 Ω to 100 KΩ, respectively; power ratings to 30 mW and 40 mW (respectively) per resistor at +70 °C; and limiting voltages to 20 V and 40 V, respectively. They also provide tight TCR of 10 ppm/°C, very low noise of ≤ 35 dB, and a low voltage coefficient of ≤ 0.01 ppm/V.
A high-stability passivated nichrome resistive layer enables the surface-mount wraparound chip resistor arrays to offer a load-life ratio of 0.02 % for 1,000 hours at +70 °C. The PRA073 and PRA074 feature simply designs by eliminating the necessity of digital drift compensation. This is thanks to their proprietary patterning and laser trimming technique, as well as the high-quality contacts between the resistive and conductive layers.
Surface mount and ROHS-compliant, the PRA073 and PRA074 high-precision thin film chip resistor arrays conform to Vishay "Green" standards and are available with humidity withstand testing to AEC-Q200. Offered with lead times of nine weeks for larger orders, the PRA073 and PRA074 are available now for sampling and in production quantities.