ROHM Semiconductor – BD9227F: The Industry’s First DC/DC Converter Capable of DC Fan Motor Speed Control


The BD9227F 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 MCU. In addition to more accurate control compare to conventional discrete configurations, ROHM’s proprietary IC analog circuit design technology achieves circuit optimization along with high frequency (1MHz) drive, which resulting the use of smaller peripheral components (i.e. coil, output capacitor), reduced footprint by 75% while improving power conversion efficiency by 19% (at 300mA output) in DC fan motor applications.automotive and industrial applications.

• 6V to 20V operating input range
• 1.0MHz fixed operating frequency
• Overcurrent hiccup period protection
• Over-voltage protection
• Thermal shutdown
• 20V/200mΩ internal power MOSFET
• Current mode control
• Under-voltage locked out
• SOP-8 package