ROHM Touts 200V Schottky Diodes for Ultra-Low Leakage Current
The latest line of RBxx8 Schottky diodes is able to withstand 200V forward voltage while their predecessor was able to withstand up to 150V.
ROHM recently announced its latest 200V, ultra-low IR Schottky barrier diode. ROHM foresees that RBxx8BM/NS200, an expansion of ROHM's RBxx8 lineup of SBDs, will be able to replace Fast Recovery Diodes (FRD) and rectifier diodes typically found in vehicles.
ROHM claims that the new SBDs improve forward voltage—specifically, reducing VF by 11%, compared to other FRDs.
Forward voltage comparison. Image from ROHM
The company attributes RBxx8BM/NS200's ability to withstand 200V to its low leakage current characteristics.
Specifications
Forward Voltage and Reverse Current
The latest line of RBxx8 Schottky diodes is able to withstand 200V forward voltage while their predecessor was able to withstand up to 150V.
Leakage current comparison. Image from ROHM
The new range of diodes has a very low reverse leakage current (up to 90% less than standard Schottky barrier diodes (as low as 8µA)) while having a forward current up to 10A and an average forward rectifier current of up to 20A.
Reduced Sized
The RBxx8BM/NS200 comes in a reduced package size with the new range of diodes 71% smaller than standard fast recovery diodes.
TO-252 DPAK and TO-263S D2PAK. Image from ROHM
All devices in the range are available in an automotive-qualified package and come in either TO-252 DPAK and TO-263S D2PAK.
Temperature
The SBD's reduction in the forward voltage drop significantly reduces heat generation. The diodes have a maximum junction temperature of 150°C. ROHM touts that the barrier metal, designed to withstand high temperatures, also improves low leakage current.
Many of these characteristics are thanks to the diode's construction, which incorporates two parallel diodes that share a common cathode connection but have two separate anode connections.
The RBxx8BM/NS200 is an expansion of ROHM's RBxx8 lineup of SBDs. Image from ROHM
This culmination of features opens a range of applications for the RBxx8 series, including automotive spaces, power supply design, motor control, and drive systems.
Silicon-based Signal Diodes vs. Schottky Diodes
The new diode is designed to solve many issues associated with a Schottky diode, especially those issues related to forward voltage, reverse current, on-resistance when conducting, and operation speed.
As a contrasting example, signal diodes based on silicon have very low leakage current and are able to withstand large reverse voltages, but can be slow to respond (i.e. not ideal for high frequency) and have large forward voltages.
On the other hand, Schottky diodes like the eight new SBDs to the RBxx8 series have a far lower forward voltage drop (typically less than 0.2V), which makes them useful for power applications.
However, they often have large reverse leakage current due to their construction (consisting of a silicon-metal junction as opposed to a PN junction). They also can't withstand reverse voltages as large as the reverse voltages that PN-based diodes can handle.
For more information on rectifiers—fast, ultrafast, standard, soft, Schottky—refer to our guide to choosing a rectifier for your power circuit.
