Stackpole Electronics’ range of products designed for medical applications includes high- and medium-voltage chip resistors, divider networks, high-precision resistors, and special precision resistors with superior moisture-resistance characteristics. The high-voltage and pulse resistors are well suited for EKG, ECG, heart defibrillators, and a vast array of other types of medical equipment. The precision resistors are suited for all types of medical instrumentation and measurement.
The HVC series of high voltage SMD chip resistors is available in sizes ranging from 0402 to 2512, resistance values from 1 kΩ to 10 GΩ, TCRs as low as 25 ppm and tolerances as low as 0.25%. Most importantly, this product series offers design engineers the ability to withstand up to 2500 V in a single standard chip resistor. Given that the normal voltage rating for a 2512 size chip is typically between 200 V and 500 V, the HVC series offers a tremendous improvement over other SMD devices and is capable of replacing much larger leaded devices. This improvement is critical to all medical equipment being downsized and adapted for use in portable applications.
For applications that don’t require such high voltage or that only require pulse power performance, there are the RVC and RPC series. The RVC series is a medium voltage SMD chip resistor that effectively doubles the voltage capability of each particular resistor size. For medium voltage requirements where cost is the driving factor, this is the ideal choice. It is available in sizes from 0603 to 2512, resistance values from 47 Ω to 51 MΩ and tolerances as low as 1%.
The RPC series is a pulse-withstanding chip that greatly improves the pulse power capability for a given size of chip. Depending on the duration of the pulse, the resistance capability for each chip size is improved by a magnitude of two to five. Sizes for this series range from 0805 to 2512 with resistance values from 0.27 Ω to 22 MΩ and tolerances as low as 1%.
The HVD series is a leaded high voltage divider SIP network that utilizes the same manufacturing technology as the HVC series. It is offered in sizes from 0.5 in. to 4 in. in length, ohmic values up to 2.0 GΩ, tolerances as low as 0.25% and voltage ratings as high as 40 kV. This product is ideal for designers seeking a single component voltage divider with outstanding TCR tracking and VCR performance.
Stackpole also offers a leaded high voltage resistor called the MG series. This product is available in standard leaded resistor sizes from 0.25 W to 2 W, resistances from 100 kΩ to 200 MΩ, voltage ratings up to 3500 V and tolerances as low as 1%. This product uses metal glaze technology.
The RNC and RNCS series are SMD precision chip resistors with proven nichrome resistance elements. Nichrome is an inexpensive resistance material well known for its outstanding precision capabilities. The RNCS adds the capability to withstand high moisture / humidity environments as good as or better than more costly tantalum nitride resistors. The RNC resistor is available in sizes from 0402 to 2512, in resistance values from 10 Ω to 2 MΩ, tolerances as low as 0.01% and TCRs as low as 5 ppm. The RNCS chip is available in a more limited range of sizes, resistance values, tolerances and TCRs.