BD95242MUV Datasheet, PDF (19/21 Pages) Rohm – 2ch Switching Regurators for Desktop PC

Technical Note
7. Operation in strong electromagnetic fields
Use in strong electromagnetic fields may cause malfunctions. Use extreme caution with electromagnetic fields.
8. Thermal shutdown circuit
This IC is provided with a built-in thermal shutdown (TSD) circuit, which is activated when the operating temperature
reaches 175℃ (standard value), and has a hysteresis range of 15℃ (standard). When the IC chip temperature rises to
the threshold, all the inputs automatically turn OFF. Note that the TSD circuit is provided for the exclusive purpose shutting
down the IC in the presence of extreme heat, and is not designed to protect the IC per se or guarantee performance when
or after extreme heat conditions occur. Therefore, do not operate the IC with the expectation of continued use or
subsequent operation once the TSD is activated.
9. Capacitor between output and GND
When a larger capacitor is connected between the output and GND, Vcc or VIN shorted with the GND or 0V line – for any
reason – may cause the charged capacitor current to flow to the output, possibly destroying the IC. Do not connect a
capacitor larger than 1000uF between the output and GND.
10. Precautions for board inspection
Connecting low-impedance capacitors to run inspections with the board may produce stress on the IC. Therefore, be
certain to use proper discharge procedure before each process of the operation. To prevent electrostatic accumulation and
discharge in the assembly process, thoroughly ground yourself and any equipment that could sustain ESD damage, and
continue observing ESD-prevention procedures in all handling, transfer and storage operations. Before attempting to
connect components to the test setup, make certain that the power supply is OFF. Likewise, be sure the power supply is
OFF before removing any component connected to the test setup.
11. GND wiring pattern
When both a small-signal GND and high current GND are present, single-point grounding (at the set standard point) is
recommended, in order to separate the small-signal and high current patterns, and to be sure the voltage change
stemming from the wiring resistance and high current does not cause any voltage change in the small-signal GND. In the
same way, care must be taken to avoid wiring pattern fluctuations in any connected external component GND.
●Thermal Derating Curve
[mW]
1000
880mW
800
70mm×70mm×1.6mm Glass-epoxy PCB
θj-a=142.0℃/W
600
With no heat sink θj-a=328.9℃/W
400
380mW
200
0
25
50
75
100
125
150 [℃]
Ambient Temperature [Ta]
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19/20
2009.04 - Rev.B