321
Regulator ICs
DC / DC converter unit
BP51L05 / BP51L12
The BP51L05 and BP51L12 are DC / DC converter units that use a pulse width modulation (PWM) system. They contain
built-in control circuits, switching devices, rectifiers, and coils, and operate if only an I / O smoothing capacitor is con-
nected. With a wide range of input voltage, the ICs are best suited for obtaining a stable local power source from a main
power supply with a large voltage variation.
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Applications
Power supplies for copiers, personal computers, word processors, industrial equipment, and maintenance tools
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Features
1) Wide range of input voltage.
2) High power conversion efficiency.
3) Heat sink unnecessary.
4) Compact SIP 9-pin package.
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Absolute maximum ratings
322
Regulator ICs
BP51L05 / BP51L12
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Electrical characteristics
S
BP51L05 (unless otherwise noted, V
I
= 15V, I
O
= 50mA, and Ta = 25
_
C)
S
BP51L12 (unless otherwise noted, V
I
= 15V, I
O
= 50mA, and Ta = 25
_
C)
F
Block diagram and measurement circuit
323
Regulator ICs
BP51L05 / BP51L12
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Pin descriptions
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Operation notes
(1)
Reduce output current according to an increase in
ambient temperature. Use the IC within the derating
curve range.
(2)
Sudden power increase at the input pin (pin 9) re-
sults in increased rush current, and may cause damage
to the hybrid IC and overshooting of output voltage.
Check for this problem, which is dependent on the rise
time of input power supply and load conditions, in the ac-
tual application. As a guide, input power supply of 10ms
or greater is required against rush current, and 100ms or
greater against overshooting. Suppress the peak value
of rush current to 2A or less.
(3)
Pins 2 to 7 are ground pins that are connected to
each other internally. Not all pins have to be used.
(4)
The IC contains no circuit to protect the output cur-
rent. If short circuit is feared, use the ICP or other protec-
tion measures.
F
Electrical characteristic curves
S
BP51L05
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ZIP