BD9142MUV Datasheet, PDF (4/5 Pages) Rohm – Silicon Monolithic Integrated Circuit

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○NOTES FOR USE
(1) Absolute Maximum Ratings
We are careful enough for quality control about this IC. So, there is no problem under normal operation, excluding
that it exceeds the absolute maximum ratings. However, this IC might be destroyed when the absolute maximum
ratings, such as impressed voltages or the operating temperature range, is exceeded, and whether the destruction is
short circuit mode or open circuit mode cannot be specified. Take into consideration the physical countermeasures
for safety, such as fusing, if a particular mode that exceeds the absolute maximum rating is assumed.
(2) GND Potential
Make setting of the potential of the GND terminal so that it will be maintained at the minimum in any operating state.
Furthermore, check to be sure no terminals are at a potential lower than the GND voltage except for SW, PGND, GND
terminals including an actual electric transient.
(3) Thermal design
Do not exceed the power dissipation (Pd) of the package specification rating under actual operation, and design
enough temperature margins.
(4) Short circuit mode between terminals and wrong mounting
In order to mount the IC on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous
mounting can destroy the IC. Furthermore, if a short circuit occurs due to foreign matters entering between terminals
or between the terminal and the power supply or the GND terminal, the IC can destroy
(5) Operation in Strong electromagnetic field
Be noted that using the IC in the strong electromagnetic radiation can cause operation failures.
(6) TSD(Thermal Shut-Down) circuit
The thermal shutdown circuit (TSD circuit) is built in this product. When IC chip temperature becomes higher, the
thermal shutdown circuit operates and turns output off. The guarantee and protection of IC are not purpose.
Therefore, do not use this IC after TSD circuit operates, nor use it for assumption that operates the TSD circuit.
(7) GND wiring pattern
Use separate ground lines for control signals and high current power driver outputs. Because these high current
outputs that flows to the wire impedance changes the GND voltage for control signal. Therefore, each ground terminal
of IC must be connected at the one point on the set circuit board. As for GND of external parts, it is similar to the
above-mentioned.
(8) Operation in supply voltage range
Functional Circuit operation is guaranteed within operation ambient temperature, as long as it is within operation
supply voltage range. The electrical characteristics standard value cannot be guaranteed.
However, there is no drastic variation in these values, as long as it is within operation supply voltage range.
(9) We are confident in recommending the above application circuit example, but we ask that you carefully check the
characteristics of this circuit before using it. If using this circuit after modifying other external circuit constants, be
careful to ensure adequate margins for variation between external devices and this IC, including not only static
characteristics but also transient characteristics. If switching noise is high, insert the Low pass filter between Vcc pin
and PVcc pin, insert the schottky barrier diodes between SW pin and PGND pin.
(10) Overcurrent protection circuit
The overcurrent protection circuit is built in the output. If the protection circuit operates more than for specific hours
(when the load is short.), the output will be latched in OFF. The output returns when EN is turned on or UVLO is
released again. These protection circuits are effective in the destruction prevention by broken accident. Do not use in
continuous circuit operation.
(11) Selection of inductor
It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. 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.
REV. A