BD3951F

Technical Note

8/9

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2009.07 - Rev.A

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10. Output capacitor between output terminal and GND must be used to prevent undesirable oscillation. Ceramic Capacitor

3.3μF～2200μF can be used. When selecting the value of the output capacitor, please make sure that the operation

on the actual application takes these conditions into account: rapid input or load transient response.

11. BD3951F might be damaged from the exceed inflow current from the terminals to VCC (for instance, VCC is short to

GND while the output capacitor is charging.). In those cases, VCC series diode (to prevent inflow current) or bypass

diode (connected from terminals to VCC) should be used externally in an application.

12. The over-current protection circuits are built in at the output to prevent the IC from being damaged when the load is

short-circuited or over-current. This protection circuit is droop type and designed not to latch-up in an unexpected huge

current driven.

13. BD3951F has thermal Shut Down protection (TSD) which performs Power Tr OFF in high Tj condition. If Tj increase

more than TSD temperature, output power transistor would OFF. After Tj cooled down, the device would be recovered

automatically. This function is designed for to protect the device at the accidental unexpected conditions. Since TSD

setting is higher temperature than absolute maximum ratings, thermal design must has done not to use this function.

14. Bypass capacitor 0.33μF～10mF into the nearest position between VCC pin and GND is recommended.

15. Insert power zenner diode between VCC terminal and GND terminal is necessary, if more than 50V serge voltage would

be supplied to VCC terminals.

16. The SOUT terminal is only activated (“H”/“L”) while the RESET is “H”. While the RESET terminal is “L”, the SOUT

terminal is always “L”.