Rohm claims BD9227F is the first power supply IC capable of controlling DC fan motor speed
Rohm claims BD9227F is the first power supply IC capable of controlling DC fan motor speed: Rohm Semiconductor claims that its buck DC/DC converter optimised for DC fan motor power supplies is the industry’s first DC/DC converter capable of DC fan motor speed control. Its integrated design reduces mounting area by 75 per cent over discrete configurations, adds the company.
Nearly half of the world’s electricity demand is used to drive motors, making it necessary to achieve more intelligent, compact, high efficiency motor drive in order to protect the environment and improve structural designs. Until now, DC fan motor power supply blocks, used in refrigerators and other equipment, are primarily configured using discrete components. This makes it difficult to provide high accuracy control or carry out high frequency drive, argues Rohm Semiconductor. As a result larger coils and output capacitors are required for the peripheral circuit, increasing mounting area considerably, which can be problematic.
The BD9227F, says Rohm, is the industry’s first power supply IC capable of controlling the rotational speed of DC fan motors with high accuracy by linearly varying the output voltage based on the PWM duty signal generated by the microcontroller (MCU). In addition to more accurate control compared with conventional discrete configurations, Rohm leverages proprietary IC analogue circuit design technology to achieve circuit optimisation and high frequency (1MHz) drive. This supports the use of smaller peripheral components (i.e. coil, output capacitor), reducing the footprint by 75 per cent, while improving power conversion efficiency by 19 per cent (at 300-mA output), contributing to greater accuracy, increased miniaturisation, and higher power conversion efficiency in DC fan motor applications, says Rohm.
The BD9227F, on the other hand, features internal frequency control that allows for drive frequencies up to 1MHz, resulting in the reduced mounting area, through the use of smaller peripheral components, including coils and capacitors.
It also supports 100 per cent duty. Integrating a high-side PMOS makes it possible to generate an output voltage at 100 per cent duty, which is rare in IC design, says Rohm. The BD9227F is supplied in an SOP8 packaging, measuring 5.0 x 6.2 x 1.7mm.