Regulator ICs
System power supply for CD playerequipped audio systems
BA3950A
With 13.3V (external transistor required), 12V , 10V, and 5.6V outputs, the BA3950A power supply IC is best suited for
CD player-equipped audio systems.
Applications
CD player-equipped audio systems
Features
1) 13.3V (external transistor required), 12V, 10V, and
5.6V outputs are built in (one output for each voltage).
2) Output current limit circuit protects the IC against
short-circuiting damage.
3) Thermal protection circuit prevents heat damage to
the IC.
4) 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 BA3950A
Block diagram
Pin descriptions
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Regulator ICs BA3950A
Input / output circuits
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Regulator ICs BA3950A
Electrical characteristics (unless otherwise noted, Ta = 25C and VCC = 8V)
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Regulator ICs BA3950A
Circuit operation
The MAIN, MOTOR, and µ-COM outputs rise when ST is 1.4V (Typ.).
The CDP output rises when MODE is 1.4V (Typ.) and ST is 1.4V (Typ.).
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Regulator ICs BA3950A
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 characteristics (Fig. 4) 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.
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(3) Preventing oscillation at each output
To stop oscillation of output, make sure to connect a capacitor having a valve 1µF or greater between GND and
each output pin. Also, be sure to connect a bypass capacitor between V
output. (To avoid the noise effect, layout the grounding
close to the IC.) Oscillation can occur if capacitance is
susceptible to temperature. We recommend using a tantalum electrolytic capacitor with minimal changes in capacitance.
CC and GND for further stabilization of
Regulator ICs BA3950A
(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
F or higher). Note
that the circuit 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) Improving ripple rejection by capacitors
Ripple rejection of the CDP and MAIN outputs can be improved by installing a capacitor that reduces the AC gain.
(7) Malfunction in intense electric fields
Note that bringing the IC into an intense electric field
(such as a radio relay station) may result in malfunction.
Estimate of allowable power dissipation (P
MAX.)
S Power consumed by CDP P
S Power consumed by µ-COM P
S Power consumed by MAIN P
S Power consumed internally by each circuit P
MAX. = P1 P2 P3 P4
P
1 = (VCC CDP) maximum load current of CDP
2 = {VCC (µ-COM)} maximum load current of µ-COM
3 = (VCC MAIN) maximum load current of MAIN
4 = VCC supply current
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Regulator ICs BA3950A
External dimensions (Units: mm)
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