The BD49101AEFS system power supply IC incorporates the multiple power supplies required for car audio systems. A 2ch DCDC converter, 5ch linear regulator, and high side switch are built in, making it possible to power an MCU, CD, tuner, USB, lighting, audio, and more using just a single IC. The optimized design, based on the high efficiency DCDC converter, minimizes heat generation and makes it possible to adopt a surface mount package without requiring thermal countermeasures. In addition, low current consumption mode switching and power supply control functions are included, improving efficiency and reducing dark current while simplifying power supply design.

■During normal operation

Conventional high-efficiency DC/DC converters require a relatively large number of external parts, leading to increased costs and larger mounting area. In response, performing a comprehensive review of the entire system and optimizing the combination of DC/DC converters and linear regulators allowed ROHM to minimize the dual DC/DC converter system and increase efficiency while reducing costs, making it possible to significantly decrease power consumption during operation (i.e. CD mechanism, MCU) to industry-low levels.

■During standby

Since DC/DC converters are prone to voltage drops when the load current is light (i.e during standby), dedicated linear regulators are built in for driving continuously operating MCUs.
Switching operation from DC/DC converters to linear regulators during standby makes it possible to minimize quiescent current when the engine is stopped.