Provides consistent output stability in automotive applications, even with high input voltage and substantial load variations.
With the automotive industry’s shift towards electrification, there is an increasing need for primary LDOs that can step down battery voltage to power MCUs and other components in ECUs. Vehicle batteries, particularly lead-acid types, often experience sudden voltage fluctuations. Primary LDOs must offer excellent line-transient responses in such conditions to ensure a consistent power supply.
ROHM has recently launched its new series of primary LDO regulators, the BD9xxM5-C (BD933M5EFJ-C, BD950M5EFJ-C, BD900M5EFJ-C, BD933M5WEFJ-C, BD950M5WEFJ-C, BD900M5WEFJ-C), designed to meet the growing demand for efficient power supply solutions in the automotive industry. The key features are:
- Regulators are rated at 45V.
- Can provide an output of 500mA.
- Ideal for powering automotive electronic components.
- Suitable for ECUs that operate directly from vehicle batteries.
ECUs and other downstream devices frequently undergo load current variations during operation, requiring LDOs with exceptional load-transient response characteristics. A high-frequency response is crucial for quick output voltage recovery, but achieving sufficient phase margin to ensure stable operation has been challenging. To address these issues, the company has developed the BD9xxM5-C series with its proprietary QuiCur high-speed load response technology. This technology enables the LDO to maintain output within 100mV of the set voltage, even as the load changes rapidly between 0 and 500mA in 1μs. The low current consumption of 9.5µA (typical) reduces power consumption in automotive applications.
The series is available in four packages allowing users to choose the most suitable package for their specific application. The new product lineup meets the basic requirements for automotive products, including operation at 150°C and compliance with the AEC-Q100 automotive reliability standard. With 18 models planned by FY2024, the series offers a wide range of package options, all featuring good response performance and low current consumption, thanks to the QuiCur technology.
These LDO regulators are suitable for various automotive applications, including powertrain systems like Fuel Injection (FI) and Tire Pressure Monitoring Systems (TPMS), body systems such as Body Control Modules, and infotainment systems including Instrument Clusters and Head-Up Displays (HUDs). This technology is a unique ‘Quick Current’ high-speed load response circuit. It maximises load response characteristics without causing instability in the feedback circuits of power supply ICs. This technology allows for stable operation with minimal output capacitance. It enables linear capacitance and output voltage fluctuation adjustment in switching regulators, significantly reducing the time and effort required for power circuit design.
