New Schottky Diodes Up Performance With Materials and Architecture
This roundup highlights how multiple companies and research teams have boosted the performance of a common component: the Schottky diode.
In applications that require fast switching characteristics and high-power operation, the diode of choice for most designers is the Schottky diode. Unlike a standard diode, which consists of a P-N junction, Schottky diodes consist of the junction of metal with either a P or an N. The result is a diode with a lower forward voltage drop and a faster reverse recovery time.
The symbol and structure of a Schottky diode. Image courtesy of Cadence
Despite their advantages compared to traditional diodes, Schottky diodes still face a number of shortcomings. Recently, several different organizations across both industry and academia have been developing better Schottky diodes to remedy such limitations.
Nexperia Releases 650 V SiC Schottky Diodes
Last week, Nexperia announced a new silicon-carbide (SiC) Schottky diode for high-power applications.
The new product, the PSC1065K, is a 650 V, 10 A diode designed explicitly for industrial-grade applications that require a high-power operation. Designed with silicon carbide, the new diode offers improved power efficiency, switching speed, and breakdown voltage compared to non-SiC offerings. Additionally, the PSC1065K can operate at temperatures up to 175°C.
The merged-PiN Schottky structure of the new 650 V SiC diodes makes them performant in demanding power conversion applications. Image courtesy of Nexperia
According to Nexperia, the part is ideally suited for applications such as switched-mode power supplies, uninterruptible power supplies (UPS), and solar inverters.
Toshiba Designs MOSFET With Embedded SBDs
At the end of last year, Toshiba had its own Schottky diode announcement—specifically, a new MOSFET created out of Schottky diodes.
Toshiba’s new SiC FET. Image courtesy of Toshiba
The new MOSFET consists of embedded Schottky barrier diodes (SBD) arranged in a check pattern. The goal of this design is to improve the on-resistance of SiC MOSFET channels associated with the bipolar conduction of SiC body diodes during reverse operation. Toshiba’s new check-pattern SiC SBD inactivates body diodes without trading off conduction or reliability.
According to the company, the resulting FET recorded an on-resistance of 2.7 mΩ・cm2, a number that is 20% lower than standard SiC MOSFETs. Importantly, this improvement in efficiency comes without any impact on the device’s reliability, according to Toshiba.
Diodes Incorporated Unveils Its First SiC SBDs
Earlier this year, Diodes Incorporated released its first silicon-carbide Schottky barrier diodes.
According to the company, the new solutions benefit from SiC’s wide-bandgap features, resulting in a more efficient and faster-switching diode. The new SBDs are said to offer a low capacitive charge, resulting in negligible switching losses and fast switching operation. Additionally, the devices offer a low forward voltage and high surge current capability, making them a useful solution for high-power solutions where thermal mitigation is important.
Diodes is releasing its first offering of SiC Schottky barrier diodes. Image courtesy of Diodes Incorporated
The new products come in two variants: the DSCxxA065 series, which features 650 V-rated products from 4 A to 10 A, and the DSCxx120 series, which features 1200 V products from 2 A to 10 A.
Penn State Devises Rubbery SBD for Flexible Electronics
Penn State University is taking a materials science approach to new Schottky diodes, with researchers recently developing a rubbery SBD.
Based on stretchable electronic materials, the resulting flexible diode offers a forward current density of 6.99 × 10−3 A/cm2 at 5 V as well as a rectification ratio of 8.37 × 104 at ±5 V. Additionally, the flexible diode and resulting logic gates made from the diodes were shown in a study to maintain their electrical properties under up to 30% tensile stretching.
A schematic of the rubbery power management system. Image courtesy of Science Advances
As described in their recently published paper, the team incorporated the flexible diodes into a variety of flexible electronic circuits, including AC-DC converters, power management systems, and logic gates. The team hopes this research can help pave the way toward a future where flexible electronics are more feasible, even for power circuits that are historically rigid.