Rainbow Electronics BA178MххT_FP - Manual (Page 10)

BA178M!!T / BA178M!!FP series
Regulator ICs
0 25 50 75 100 125 150
2.5
5
7.5
10
12.5
0
AMBIENT TEMPERATURE : Ta ( ° C)
POWER DISSIPATION : Pd (W)
(1) 10.0
(2) 1.0
Fig.10 Thermal derating characteristic
(TO252
− 3)
(1) Infinite heat sink, θ j − c = 12.5 ( ° C / W)
(2) No heat sink θ j − c=125.0 ( ° C /W)
" " " " Operation notes
(1) Although the circuit examples included in this handbook are highly recommendable for general use, you should
thoroughly familiar yourself with the circuit characteristics as they relate to your own conditions. If you intend
to change the number of external circuits, leave an ample margin, taking into account discrepancies in both static
and dynamic characteristics of external parts and Rohm ICs. In addition, please be advised that Rohm cannot
provide complete assurance regarding patent rights.
(2) Operating power supply voltage
When operating within the normal voltage range and within the ambient operating temperature range, most circuit
functions are guaranteed. The rated values cannot be guaranteed for the electrical characteristics, but there are no
sudden changes of the characteristics within these ranges.
(3) Power dissipation
Heat attenuation characteristics are noted on a separate page and can be used as a guide in judging power
dissipation.
If these ICs are used in such in a way that the allowable power dissipation level is exceeded, an increase in the chip
temperature could cause a reduction in the current capability or could otherwise adversely affect the performance of
the IC. Make sure a sufficient margin is allowed so that the allowable power dissipation value is not exceeded.
(4) Preventing oscillation in output and using bypass capacitors
Always use a capacitor between the output pins and the GND to prevent fluctuation in the output and to prevent
oscillation between the output pins and the GND of the application’s input (V
IN
µF should be used.)
Changes in the temperature and other factors can cause the value of the capacitor to change, and this can cause
oscillation. To prevent this, we recommend using a tantalum capacitor which has minimal changes in nominal
capacitance.
Also, we recommend adding a bypass capacitor of about 0.33
µF between the input pin and the GND, as close to the
pin as possible.
(5) Thermal overload circuit
A built-in thermal overload circuit prevents damage from overheating. When the thermal circuit is activated, the various
outputs are in the OFF state. When the temperature drops back to a constant level, the circuit is restored.
(6) Internal circuits could be damaged if there are modes in which the electric potential of the application’s input (V
IN
) and
GND are the opposite of the electric potential of the various outputs. Use of a diode or other such bypass path is
recommended.
(7) Although the manufacture of this product includes rigorous quality assurance procedures, the product may be
damaged if absolute maximum ratings for voltage or operating temperature are exceeded. If damage has occurred,
special modes (such as short circuit mode or open circuit mode) cannot be specified. If it is possible that such special
modes may be needed, please consider using a fuse or some other mechanical safety measure.
(8) When used within a strong magnetic field, be aware that there is a slight possibility of malfunction.