Pass Stress and High Temperature Test Requirements For ADAS Development with KEMET T598 Capacitors

about 2 years ago by Sam Holland

Even though tantalum polymer capacitors have a lot of significant features like high volumetric efficiency, low equivalent series resistance, high capacitance, high ripple handling, etc, it has always been a great challenge to pass the Automotive Electronics Council's AEC-Q200 stress test...
The reason for this is that such capacitors were previously not able to withstand the extreme temperatures involved—something which is one of the core qualifying criteria for AEC-Q200. This is also why they’ve mostly been used as low-voltage DC to DC converters in computers, telecom power supplies, and similar devices. On the other hand, the automotive industry has resultantly not been able to utilise tantalum polymer capacitors in their applications.
Now, however, Kemet Electronics has addressed this concern by improving temperature resistance and ultimately developing the T598 series: the market’s first tantalum polymer surface-mount capacitor series to pass AEC-Q200 guidelines.
The Kemet T598 tantalum polymer capacitors are made with a conductive polymer cathode, capable of delivering a single-digit equivalent series resistance (ESR), which significantly reduces the self-heating of capacitors and minimises energy losses. The low ESR helps to—not only achieve stable performance—but also enable the devices to retain the capacitance at higher frequencies. 
Simply put, the T598 capacitors combine the high capacitance of aluminium electrolytic, the low ESR of multilayer ceramic, and the high volumetric efficiency of tantalum—all into a single package. And given that the single-digit ESR allows the usage of single components instead of multiple devices, it will help designers to achieve cost savings. 
A Kemet organic capacitor. Image courtesy of Kemet.

Product Features

The T598 polymer capacitors are specifically designed to operate under harsh environmental conditions with a temperature between −55°C to 105°C/125°C/150°C. These capacitors also offer high capacitance/voltage ratings, with a capacitance range of 10 to 470 µF and a voltage range of 2.5 to 50 V. 

Furthermore, they can handle large ripple currents without undergoing any thermal stress. T598 polymer capacitors can deliver robust and stable performance for up to 2,000 hours, which is equivalent to a lifecycle of approximately 15 years. These capacitors are manufactured in an ISO TS 16949-certified plant and are subject to a PPAP/PSW (Production Part Approval Process/Part Submission Warrant) and change control.



Since T598 Electrolytic capacitors are strictly designed to meet the needs of the automotive industry, they are ideal for a variety of ADAS (advanced driver assistance systems) features in automotive applications, such as blind spot detection, emergency brake assistance, and adaptive cruise control. They can also be used in other safety-related features, including airbag occupant detection and alarm systems. T598 capacitors can also be used in the in-vehicle infotainment systems. 

In addition to providing reliable, stable and long-lasting performance under harsh environments, the Kemet T598 polymer electrolytic capacitors help engineers to design more space-efficient automotive modules (consider the single-digit ESR). Since these capacitors are halogen-free and RoHS-compliant, they are also environmentally-friendly.

With the increased demand for the transition of manual to hybrid/fully automatic vehicles, the need for innovative and miniature components will also increase significantly—and the T598 tantalum polymer capacitors prove a perfect reflection of that.