Vishay’s new RCA‑SR e3 series are AEC‑Q200 qualified thick film chip resistors designed for sulfur‑rich and thermally demanding environments in automotive, industrial, and telecom electronics.
By combining proven sulfur resistance with tight long‑term stability, they target design engineers who struggle with latent field failures caused by sulfur contamination and drift in standard thick film parts.
Key features and benefits
The RCA‑SR e3 thick film chip resistors family is positioned as a standard thick film chip platform with enhanced sulfur resistant resistors for applications exposed to polluted air, rubber and fuel vapors, or industrial atmospheres. The series is qualified to AEC‑Q200, making it suitable for automotive control units and other high‑reliability electronics where component derating and long service life are critical.
Key characteristics include:
- Sulfur withstand capability tested per ASTM B809‑25, maximum resistance drift of 1% after 1000 h at 60 °C, addressing failure modes in sulfur‑containing atmospheres where conventional silver‑based terminations can corrode and go open.
- Long‑term stability with ΔR/R ≤ 1% after 1000 h at rated power at 70 °C, helping maintain calibration and accuracy over equipment lifetime.
- Standard thick film construction with a protective coating for electrical, mechanical, and climatic protection, supporting robust performance under vibration, temperature cycling, and humidity.
- RoHS‑compliant and halogen‑free design, simplifying environmental compliance for global platforms.
- Pure matte tin terminations compatible with both lead‑free and legacy lead‑containing soldering processes, easing second‑source and redesign scenarios.
For purchasing teams, the fact that RCA‑SR e3 is framed as a standard thick film series with added sulfur robustness means it can be treated as a drop‑in improvement over conventional chips in many BOMs, rather than as a niche specialty resistor.
Typical applications
Sulfur‑resistant chip resistors are relevant wherever electronics operate near combustion, rubber, fuels, or industrial emissions. The RCA‑SR e3 series is positioned for automotive, industrial, and telecommunications equipment that must remain stable over long field lifetimes.
Typical use cases include:
- Automotive ECUs and sensors mounted in the engine compartment or underbody, exposed to exhaust gases and road pollution.
- Industrial control systems in refineries, chemical plants, or rubber processing lines where airborne sulfur compounds are present.
- Telecommunications infrastructure installed near roads or industrial areas, where long‑term stability and low drift reduce maintenance visits.
- General purpose signal conditioning, pull‑ups, voltage dividers, and bias networks where latent sulfur‑induced opens would be costly or difficult to diagnose.
In many of these applications, the main value of a sulfur‑resistant series is not a visible performance boost, but reduced field failures and fewer unplanned service events over the product lifetime.
Technical highlights
The RCA‑SR e3 family spans five popular chip sizes and covers a broad resistance range, making it easy to design in across different power and voltage levels.
Case sizes and ratings
- Available case sizes: 0201, 0402, 0603, 0805, 1206.
- Power ratings at 70 °C (P70):
- RCA0201‑SR e3: 0.05 W.
- RCA0402‑SR e3: 0.1 W.
- RCA0603‑SR e3: 0.125 W.
- RCA0805‑SR e3: 0.25 W.
- RCA1206‑SR e3: 0.25 W.
- Maximum operating voltage:
- 0201: 30 V.
- 0402 and 0603: 75 V.
- 0805: 150 V.
- 1206: 200 V.
- Operating temperature range: -55 °C to +155 °C.
In practice, the combination of -55 °C to +155 °C and AEC‑Q200 qualification allows these parts to be used in automotive and industrial designs that face aggressive thermal cycling, provided standard derating guidelines from the manufacturer datasheet are observed.
Resistance range, tolerance, and TCR
- Resistance range:
- RCA0201‑SR e3: 10 Ω to 1 MΩ; jumper (0 Ω).
- RCA0402‑SR e3, RCA0603‑SR e3, RCA0805‑SR e3, RCA1206‑SR e3: 10 Ω to 10 MΩ; jumper (0 Ω).
- Resistance tolerances: ±1% and ±5%.
- TCR options:
- 0201: ±200 ppm/K.
- 0402, 0603, 0805, 1206: ±100 ppm/K and ±200 ppm/K.
For many control and sensing circuits, ±100 ppm/K is sufficient to keep temperature‑induced error within a few tenths of a percent over a wide temperature swing, while ±200 ppm/K is adequate for less critical pull‑up and biasing roles. According to the manufacturer’s datasheet, designers should select the appropriate TCR and tolerance combination based on the total error budget of their analog or mixed‑signal chain.
Design‑in notes for engineers
When considering a switch from standard thick film chips to sulfur‑resistant devices like RCA‑SR e3, the main design‑in effort is usually at the footprint and derating level rather than circuit topology. Because the series uses mainstream case sizes and power ratings, many existing 0201–1206 pads can be reused if the designer confirms the land pattern against the manufacturer’s recommended footprint.
Practical design‑in recommendations:
- Use sulfur‑resistant types in positions exposed to air exchange or external pollution, such as near connectors, vents, or on boards placed in engine compartments or industrial cabinets with air circulation.
- Pay attention to the specified operating voltage and power rating; in high‑voltage dividers or line‑connected sensing, select 0805 or 1206 parts and follow the derating curves from the datasheet instead of operating at the absolute maximum values.
- Where long‑term calibration is important (current shunts for low current ranges, precision dividers for ADC reference scaling), prefer the ±1% tolerance and ±100 ppm/K TCR options where available.
- For jumpers (0 Ω), check the recommended current and power limits in the official documentation, as these are often constrained by track width and thermal behavior rather than the nominal “0 Ω” label.
- In automotive designs targeting AEC‑Q200, document the alignment between the component’s qualification and the system‑level environmental test plan, especially for sulfur exposure and long‑term drift.
From a supply‑chain perspective, consolidating on a sulfur‑resistant series like RCA‑SR e3 can simplify global product platforms, since the same BOM can be used in both benign and sulfur‑rich markets without separate variants dedicated to harsh environments.
Source
This article is based on an official Vishay Intertechnology press release and associated product information for the RCA‑SR e3 sulfur‑resistant thick film chip resistor series, with additional commentary aimed at design and purchasing engineers.