Feb 7, 2020 – ROHM recently announced the BV2Hx045EFU-C high voltage (41V) dual channel output high side switch (Intelligent Power Devices, IPD) optimized for automotive ECUs in transmission control, engine control, and other vehicle systems. IPDs are semiconductor devices that protect electronic circuits from breakdown. Unlike conventional fuses, IPD as semiconductor fuses can protect circuits without degrading or breaking down, making it possible to achieve maintenance-free systems.
In recent years, as electrification has progressed following technological innovations in the automotive field, the concept of functional safety that can minimize risk and severity of accidents in the event of emergencies is needed to achieve safer vehicle systems. Fuses are typically used as a countermeasure to protect systems from overcurrent in the event of ECU malfunctions, but issues related to maintenance and degradation caused by aging can arise after the fuse melts, calling for increased adoption of IPDs.
The new BV2Hx045EFU-C are the industry’s first high-side IPDs capable of providing standalone protection against overcurrent by incorporating an original overcurrent protection function. Conventional IPDs only protect against inrush current at startup, so MCUs and overcurrent detection ICs are needed for protection of steady-state currents, and there is still the possibility of an out of control situation due to compatibility issues with subsequent circuits connected to the IPD output. In contrast, this new series can protect the system against both inrush and steady state overcurrent, ensuring greater system safety by providing a high reliability solution with fewer parts compared to conventional products. In addition, the overcurrent protection range can be adjusted with external components to enable broad compatibility.
ROHM is committed to developing high reliability and high functionality devices and contributing to safety, security and ecology in the automotive field.
Key Features
1. The industry’s first standalone overcurrent protection function contributes to greater system reliability: Standard high side IPDs only protect against inrush current at startup, while MCUs and overcurrent detection ICs are needed to provide overcurrent protection for steady-state currents. Once an overcurrent condition of the steady state current is detected, the IPD output is controlled (ON/OFF) by the MCU Enable signal. Therefore, depending on the capacitance value of the subsequent circuit connected to the IPD output, inrush current at startup can cause overcurrent protection to be repeatedly detected and reset, resulting in oscillation.
In contrast, the BV2Hx045EFU-C integrates a proprietary function that provides standalone protection from both inrush and steady state overcurrent, ensuring stable drive operation and greater system reliability. In addition, an error signal can be sent to the MCU when an abnormality (i.e. overcurrent) has been detected, providing functional safety for the entire system.
2. Protects ECUs in a variety of systems: This new series enables adjustment of the inrush protection time and abnormal current threshold of the steady state current by simply changing the external capacitor and resistor constants, ensuring support for a wide range of systems.
3. Significantly reduces the number of parts required: The BV2Hx045EFU-C are equipped with an original protection function that delivers standalone overcurrent protection for the entire system. This makes it possible to eliminate up to 7 external parts compared to conventional solutions, decreasing mounting area by as much as 70%.
Application Examples
- ECUs
- Transmission Control Units
- Idle-Stop Control Units
- Automotive Lamps
- Hydraulic Suspension Control Units
- Anti-Lock Braking Systems
Ideal for ECU protection in vehicle electrical systems. In addition, as semiconductor switches do not generate sound during switching, they can be used for a wide variety of relay (circuit switching) applications.
The lineup has been expanded to include the 5.0mm×2.5mm (2010 type) package GMR50 series in addition to the existing 6.4mm×3.2mm (2512 type) package GMR100.
Terminology
Intelligent Power Devices (IPD) IPDs are semiconductor devices that protect electronic circuits from breakdown. They are also called “high side and low side switch” and “e-Fuse” in the market.
Functional Safety
Functional safety includes safety measures (concepts for ensuring safety) that minimize risk by adding functionality such as monitoring and protective equipment. In the automotive market, functional safety minimizes risk to an acceptable level in order to prevent bodily injury in the event of malfunction due electronic system failure.
