| Automotive Circuit FRD, SBD Replacement Trend
| High-performance, high-reliability SBDs require high voltage resistance
| ROHM Launches Ultra-Low IR RBxx8BM200/NS200 There is a movement to replace rectifier diodes and fast recovery diodes (FRDs) in automotive and power supply circuits with Schottky-barrier diodes (SBDs).
▲ Comparison of characteristics of FRD, general SBD, and ROHM SBD
(Image provided by ROHM)
This is because many automobile OEMs are pursuing 'mechanical-electric integration' in drive systems such as 48V mild hybrids, which integrates the motor and its surrounding components into a single module.
In addition, as the requirements for high functionality and reliability become more stringent in systems using existing 150V applications, higher withstand voltage of SBDs is also required.
However, as the operating environment temperature increases, the I
R characteristics of SBD deteriorate and thermal runaway occurs easily. I
R (Reverse Current) is the reverse current that occurs when voltage is applied in the reverse direction. The smaller the value, the less power consumption.
▲ ROHM launches RBxx8BM200 and RBxx8NS200
(Image provided by ROHM)
Accordingly, ROHM announced on the 5th that it will release new ultra-low I
R 200 V withstand voltage SBD products, 'RBxx8BM200' and 'RBxx8NS200' for automotive systems. The RBxx8BM200 is released in a TO-252 package, and the RBxx8NS200 is released in a TO-263S package.
▲ Comparison of I R characteristics of general SBD and RBxx8 series
(Image provided by ROHM)
The RBxx8BM200/NS200, which employs a barrier metal optimized for high temperatures, has improved the I
R characteristics, which is the biggest problem when using SBDs in circuits of automobiles and power equipment. With its ultra-low IR characteristics, the RBxx8BM200/NS200 can replace FRDs in automotive systems that have previously required 200 V withstand voltage.
▲ Comparison of V F characteristics of SBD and FRD (Image provided by ROHM)
In addition, it can reduce the V
F characteristics by approximately 11% compared to FRD, contributing to lower power consumption in applications. V
F (Forward Voltage) is the voltage value generated across a diode when current flows in the forward direction. The smaller the value, the less power consumption.
The RBxx8BM200/NS200, which suppresses heat generation by lowering the V
F characteristic, enables a smaller package design than the previous RBxx8 series. ROHM is currently also promoting the development of middle power package products.
▲ Future miniaturization goals (Image provided by ROHM)
This allows for a replacement of the 5.9 × 6.9 mm size used in future FRDs with a smaller package of 2.5 × 4.7 mm. In other words, the mounting area can be reduced by 71%.
“As of last year, ROHM ranked third in the global diode market by a narrow margin,” said Hiroyuki Tanaka, Group Leader of the Product Development Group at ROHM’s Power Diode Manufacturing Division. “In particular, we ranked first in the global automotive diode market with a 19.8% share.”
▲ Rohm Power Diode Manufacturing Department Product Development Group Manager
Hiroyuki Tanaka (Photo = Reporter Lee Su-min)
He continued, “The RBxx8BM200/NS200 recently released by ROHM is a high-function, high-reliability, high-voltage 200 V SBD suitable for operation in high-temperature environments,” and “ROHM will continue to develop products that are helpful to customers in response to the needs of the automotive market.”
Meanwhile, the RBxx8 series began sample shipments in July, and mass production is scheduled to begin in September with a production capacity of 1 million units per month.
