Bulk Metal Z-Foil Wraparound Surface-Mount Resistor from Vishay

Vishay has extended the range of its wraparound termination VSM and VSMP chip resistors with the introduction of the 0603 case size. The demand for smaller components is applicable to all electronics, including precision circuitry, but their practical limits are fast approaching. The VSMP0603 retains all of the Foil attributes of accuracy, frequency response, electrostatic discharge (ESD) immunity up to 25 kV, and load and temperature stability, in exchange for a reduced range of resistance. Now for the first time, any value from 100 Ω to 5 kΩ is available with ±0.2 ppm/°C TCR and up to a 100-mW power rating at 70°C. Vishay Foil resistors are not restricted to standard values, and Vishay can supply as required values (e.g. 200.049 kΩ or 200 kΩ) at no extra cost or delivery time.

The new resistor features a full wraparound termination that ensures safe handling during the manufacturing process, as well as providing stability during multiple thermal cycling. Wraparound terminations render the VSMP0603 solderable in various board positions, and its .06-in by .03-in footprint is the smallest yet available in Foil-based technology. Smaller sizes are available in thick and thin film products, but their attachment method becomes very critical to reliability during final assembly.

The VSMP0603 is built to handle unconventional environmental conditions with minimal drift, making it well suited for military/space applications according to EEE-INST-002 specifications and MIL-PRF 55342. The ultimate component for analog applications, the resistors' construction guarantees a high level of reliability, stable operation in harsh conditions, and high resistance to thermal shock, mechanical shock, and vibrations. The device can withstand electro-static discharges (ESD) in excess of 25 kV.

The resistor allows designers to achieve much better performance by combining a range of high-precision specifications in a single device. In addition to its low TCR, tight tolerance, and excellent load life stability values, the VSMP0603 offers PCR (ΔR due to self heating) of ±5 ppm at rated power, a low voltage coefficient of < 0.1 PPM/V, and current noise of < -40 dB. The resistor provides a fast thermal stabilization of less than 1 second and a non-inductive (< 0.08 µH), non-capacitive design. The device is available with standard tin/lead or lead-free terminations.

Typical applications for the VSMP0603 will include dc-to-dc converters, feedback and sense circuits, and high precision amplifiers in test and measurement instrumentation; laboratory, industrial, and medical systems; electron beam applications; satellites and aerospace systems; commercial and military avionics; audio systems; down-hole drilling instrumentation; and weigh scales.