Regulator ICs
System power supply for CD playerequipped audio systems
BA3963
With 5V and 7V outputs and a reset output that detects the 5V output, the BA3963 power supply IC is best suited for
CD player-equipped audio systems.
Applications
CD player-equipped audio systems
Features
1) A 5V output, a 7V output, and a reset output are built
in.
2) All output circuits use a PNP transistor with a low saturation voltage.
3) Current limit circuit protects the IC against short-circuiting damage.
4) Thermal protection circuit prevents heat damage to
the IC.
5) Compact SIP-M12 package allows a large power dissipation.
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
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Regulator ICs BA3963
Block diagram
Pin descriptions
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Regulator ICs BA3963
Input / output circuits
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Regulator ICs BA3963
Electrical characteristics (unless otherwise noted, Ta = 25C and VCC = 12V)
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Regulator ICs BA3963
Circuit operation
OUT 5V rises when MODE 1 is 1.4V (Typ.), and OUT 7V
rises when MODE 2 is 1.4V (Typ.). The reset output rises
with a delay time (td) when OUT 5V is 4.2V (Typ.), and
rises when OUT 5V is 4.1V (Typ.).
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Regulator ICs BA3963
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Regulator ICs BA3963
Application example
Operation notes
(1) Operating power supply voltage
When operating within proper ranges of power supply
voltage and ambient temperature, most circuit functions
are guaranteed. Although the rated values of electrical
characteristics cannot be absolutely guaranteed, characteristic values do not change drastically within the
proper ranges.
(2) Power dissipation (Pd)
Refer to the heat reduction curves (Fig. 5) and the rough
estimation of IC power dissipation given on a separate
page. If power dissipation exceeds the allowable limit,
the functionality of IC will be degraded (such as reduction
of current capacity by increased chip temperature).
Make sure to use the IC within the allowable range of
power dissipation with a sufficient margin.
(3) Preventing oscillation at each output
To stop oscillation of output, make sure to connect a capacitor having a capacitance of 10µF or greater between
GND and each output pin. Also, the 5V output ripple rejection is improved by connecting a capacitor having a
capacitance of 1µF or greater between pins 4 and 6.
When connecting the capacitors, be sure to connect the
polarities correctly. Oscillation of output can occur if capacitance is susceptible to temperature. We recommend
using a tantalum electrolytic capacitor with minimal
changes in capacitance.
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Regulator ICs BA3963
(4) Overcurrent protection circuit
An overcurrent protection circuit is installed in each output system, based on the respective output current. This
prevents IC destruction by overcurrent, by limiting the
current with a curve shape of “7” in the voltage-current
graph. The IC is designed with margins so that current
flow will be restricted and latching will be prevented even
if a large current suddenly flows through a large capacitor. Note that these protection circuits are only good for
preventing damage from sudden accidents. Make sure
your design does not cause the protection circuit to operate continuously under transitional conditions (for
instance, when output is clamped at 1V
mode circuit operates at 1V
F or lower). Note that the cir-
F or higher, short
cuit ability is negatively correlated with temperature.
FThermal derating curve
(5) Thermal protection circuit
A built-in thermal protection circuit prevents thermal
damage to the IC. All outputs are switched OFF when the
circuit operates, and revert to the original state when
temperature drops to a certain level.
(6) Grounding
To minimize the variation of output voltage due to variations in load current, the GND (pin 12, for large current)
and the PRE GND (pin 1 1, for small current) pins are separately provided. Make sure to connect circuits to correct
pins.
Estimate of allowable power dissipation (P
MAX.)
S Power consumed by OUT 5V P
S Power consumed by OUT 7V P
S Power consumed by the reset output P
S Power consumed internally by each circuit P
MAX. = P1 P2 P3 P4
P
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1 = (VCC 5V) maximum output current of OUT 5V
2 = (VCC 7V) maximum output current of OUT 7V
3 = (VCC 4.95V) maximum output current of the reset output
4 = VCC supply current
Regulator ICs BA3963
External dimensions (Units: mm)
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