Technical Note
BD4154FV
10. Electrical characteristics
The electrical characteristics in the Specifications may vary, depending on ambient temperature, power supply voltage,
circuit(s) externally applied, and/or other conditions. Therefore, please check all such factors, including transient
characteristics, that could affect the electrical characteristics.
11. Capacitors applied to input terminals
The capacitors applied to the input terminals (V3_IN, V3AUX_IN and V15_IN) are used to lower the output impedance of
the connected power supply. An increase in the output impedance of the power supply may result in destabilization of
input voltages (V3_IN, V3AUX_IN and V15_IN). It is recommended that a low-ESR capacitor be used, with a lower
temperature coefficient (change in capacitance vs. change in temperature), Recommended capacitors are on the order of
0.1 μF for V3AUX_IN, and1 μF for V3_IN and V15_IN. However, they must be thoroughly checked at the temperature
and with the load range expected in actual use, because capacitor selection depends to a significant degree on the
characteristics of the input power supply to be used and the conductor pattern of the PC board.
12. Capacitors applied to output terminals
Capacitors for the output terminals (V3, V3_AUX, and V15), should be connected between each of the output terminals
and GND. A low-ESR, low temperature coefficient output capacitor is recommended-on the order of 1 μF for V3 and V15
terminals, and 1μF less for V3_AUX. However, they must be thoroughly checked at the temperature and with the load
range expected in actual use, because capacitor selection depends to a significant degree on the temperature and the
load conditions.
13. Not of a radiation-resistant design.
14.Allowable loss (Pd)
With respect to the allowable loss, please refer to the thermal derating characteristics shown in the Exhibit, which serves
as a rule of thumb. When the system design causes the IC to operate in excess of the allowable loss, chip temperature
will rise, reducing the current capacity and decreasing other basic IC functionality. Therefore, design should always
enable IC operation within the allowable loss only.
15. Operating range
Basic circuit functions and operations are warranted within the specified operating range the working ambient temperature
range. Although reference values for electrical characteristics are not warranted, no rapid or extraordinary changes in
these characteristics are expected, provided operation is within the normal operating and temperature range.
16. The applied circuit example diagrams presented here are recommended configurations. However, actual design
depends on IC characteristics, which should be confirmed before operation. Also, note that modifying external circuits
may impact static, noise and other IC characteristics, including transient characteristics. Be sure to allow sufficient
margin in the design to accommodate these factors.
17. Wiring to the input terminals (V3 IN, V3AUX IN, and V15 IN) and output terminals (V3, V3AUX and V15) of the built-in FET
should be carried out with special care. Using unnecessarily long and/or thin conductors may decrease output voltage
and degrade other characteristics.
18. Heatsink
The heatsink is connected to the SUB, which should be short-circuited to the GND. Proper heatsink soldering to the PC
board should enable lower thermal resistance.
●Power Dissipation
Mounted on board
70mmx70mmx1.6mm glass-epoxy PCB
θj-a=153.8℃/W
[mW]
1000
812.5mW
800
Without heat sink
θj-a=250.0℃/W
500mW
600
100℃
400
200
0
0
25
50
75
125
100
150
[℃]
Ambient Temperature (Ta)
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2009.05 - Rev.A
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