BD9150MUV Datasheet, PDF (17/19 Pages) Rohm – Output 1.5A or Less High Efficiency Step-down Switching Regulator with Built-in Power MOSFET

BD9150MUV
Technical Note
7. Ground wiring pattern
If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND pattern from
the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that resistance to the wiring
pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of the small-signal GND. Pay attention
not to cause fluctuations in the GND wiring pattern of external parts as well.
8 . Selection of inductor
It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. Especially, in case output
voltage is set 1.6V or more, note that use of a high DCR inductor will cause an inductor loss, resulting in decreased output
voltage. Should this condition continue for a specified period (soft start time + timer latch time), output short circuit protection
will be activated and output will be latched OFF. When using an inductor over 0.1Ω, be careful to ensure adequate margins
for variation between external devices and this IC, including transient as well as static characteristics. Furthermore, in any
case, it is recommended to start up the output with EN after supply voltage is within operation range.
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2009.05 - Rev.A