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Regulator ICs
Reference voltage power supply
BA3932
The BA3932 is a monolithic reference voltage power supply IC for use in CD radio cassette players.
Applications
CD radio cassette players, mini-component stereo audio systems
Features
1) With 9.0V output for audio power supply, 5.0V output
for microcontrollers, 5.0 and 8.0V outputs for CD
players, 14.7V output for motor drivers, the IC is best
suited for CD radio cassette players.
2) Precise power supply (5V ± 0.1V) can be obtained by
using external reference voltage input (only AUDIO
output has an internal reference voltage system).
Absolute maximum ratings (Ta = 25C)
3) Zero standby current. (Typ.)
4) Output current limit circuit protects the IC against
short-circuiting damage.
5) Compact SIP-M12 package allows a large power dissipation (3W: no heat sink).
6) Thermal protection circuit prevents heat damage to
the IC.
Recommended operating conditions
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Regulator ICs BA3932
Block diagram
Pin descriptions
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Regulator ICs BA3932
Input / output circuits
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Regulator ICs BA3932
Electrical characteristics (unless otherwise noted, Ta = 25C and VCC = 16.0V)
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Regulator ICs BA3932
Circuit operation
(1) Timing chart
AUDIO 9V, MOTOR 14.7V, and COM 5V are output regardless of MODE SW.
RADIO 5V rises when MODE SW is 1.4V (typical), and
CD 8V and CD 5V rise when MODE SW is 3.2V (typical).
(2) Estimate of allowable power dissipation
Except under transitional conditions, the power dissipation of this IC is 3W per unit at 25C. See Fig. 3 for heat
reduction characteristics, including some cases where
heat sinks are used.
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Regulator ICs BA3932
Calculation of PMAX
S Power consumed by AUDIO 9V
1 = (VCC – 9.0V)I1
P
S Power consumed by MOTOR 14.7V
P
2 = (VCC – 14.7V)I2
S Power consumed by CD 8.0V
3 = (VCC – 8.0V)I3
P
S Power consumed by CD 5.0V
4 = (VCC – 5.0V)I4
P
S Power consumed by RADIO 5.0V
P
5 = (VCC – 5.0V)I5
S Power consumed by COM 5.0V
6 = (VCC – 5.0V)I6
P
S Power consumed internally by each circuit
7 = VCCcircuit current
P
1 = maximum output for AUDIO 9V
∗I
I
2 = maximum output for MOTOR 14.7V
3 = maximum output for CD 8.0V
I
4 = maximum output for CD 5.0V
I
5 = maximum output for RADIO 5.0V
I
6 = maximum output for COM 5.0V
I
FOperation 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. 3) and
the rough estimation of IC power dissipation given on a
separate page. Make sure to use the IC within the allowable power dissipation with a sufficient margin.
(3) Preventing oscillation at each output and installing
a ripple filter capacitor.
To stop oscillation of output, make sure to connect a capacitor between GND and each of the AUDIO 9V (pin 1),
RADIO (pin 4), COM (pin 5), CD 5V (pin 6), CD 8V (pin
7), and MOTOR 14.7V (pin 11) output pins. We recommend using a tantalum electrolytic capacitor having a capacitance of 10µF or greater (100µF or greater for AUDIO 9V) with minimal temperature susceptibility. Also,
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sudden deterioration of the AUDIO 9V ripple rejection
during a power drop can be prevented by connecting a
capacitor (220µF or greater recommended) to the C pin
(pin 2).
(4) Overcurrent protection circuit
An overcurrent protection circuit is installed on the AUDIO 9V (pin 1), RADIO (pin 4), COM (pin 5), CD 5V (pin
6), CD 8V (pin 7), and MOTOR 14.7V (pin 11) outputs,
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, if output
is clamped at 1V
F or lower).
at 1V
F or higher, short mode circuit operates
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Regulator ICs BA3932
(5) Reference voltage
Because output voltage is dependent on the input reference voltage, unstable input results in output wavering
and degradation of ripple rejection. Take care when setting the reference voltage power supply. Note that the
AUDIO output, which has a built-in reference voltage
system, is not affected by the external reference voltage.
Thermal derating curve
(6) 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.
(7) Grounding
Each ground line in the application circuit must be adequately short regarding the PREGND (pin 3) and GND
(pin 12) pins. Make sure to arrange the ground lines, the
AUDIO system, and other outputs in a pattern that prevents electric interference.
External dimensions (Units: mm)
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