Field-Plated Super Barrier Rectifier: An Evolution in Power Rectifier Technology
A central component to a power circuit, or any type of circuit where a signal needs to be conditioned, is a rectifying diode. Traditionally, diodes from one of two families are used in these applications: the pn-junction diode and the Schottky Barrier diode. These technologies are well-established in circuit design and form the basis of most IC fabrication techniques. The Schottky diode came first: in 1926, followed by the pn junction diode in 1940. Here, we will discuss a ground-breaking innovation in rectifier technology that uniquely captures the benefits provided by each of these traditional devices and integrates them into a single component.
Today's rectifying devices are a far cry from those of the early 20th century, but still possess physical limitations that preclude their use in certain applications, and offer many limitations where they are used. These products often provide only partial design satisfaction, and significant design trade-offs have to be made to compensate for parametric deficiencies when designing for a strength of a particular technology.
A typical trade-off comparison looks like this:
|
pn-junction diode |
Schottky barrier diode |
"fast recovery" diode |
Forward Voltage, Vf |
High |
Low |
High |
Reverse Leakage Current, Irm |
Low |
High |
Low |
Breakdown Voltage range, Vrrm |
High |
Medium |
High |
Surge reliability |
High |
Low |
High |
Thermal immunity |
High |
Low |
High |
Switching Speed, (1/trr) |
Low |
High |
High |
As seen from the above table, important operating characteristics are complementary between the pn-junction and the Schottky barrier diode. This is due to the fundamental physics that describes the mode of operation of the two device types.
No device from these families satisfies relevant parameters, until the Super Barrier Rectifier was introduced by Diodes. Our state-of-the-art, integrated circuit, wafer-processing technology allows the design and manufacturability of a device that is able to integrate and improve the benefits of the two existing rectifier technologies into a single device. The creation of a finite conduction cellular IC, combined with inherent design uniformity, has allowed manufacturing costs to be kept competitive with existing power-device technology, thus producing the first real breakthrough in rectifier technology in over two decades. This technology was designed with the following key objectives:
We launched this next generation of SBR products in 2020 with the Field-Plated Super Barrier Rectifier (SBRFP). It features lower forward voltage to minimize conduction losses, thereby increasing power efficiency. It is also robust enough against thermal runaway at high temperatures to withstand reverse energy, which improves system reliability.
We have embodied these desirable functions into a single component, which, through increased efficiency of power-conditioning circuits, increases the value of subsystem design. Traditionally incompatible in a single component, the unification of these features permits the development and integration of systems previously not considered.
SBR Application Notes
Item # Title (Abbreviated)
AN1010A SBR® Avalanche Energy
AN1158 Super Barrier Rectifier (SBR®) Improves Automotive Supply Line Protection to ISO7637
AN1149 Super Barrier Rectifiers (SBR®) Improve Daytime Running Lamp (DRL) Efficiency