ROHM BAOOST

Regulator ICs
Low saturation voltage type regulator
with ON / OFF switch
BAST series
The BAST series are variable, fixed output low drop-out type voltage regulators with an ON / OFF switch. These
regulators are used to provide a stabilized output voltage from a fluctuating DC input voltage.
Fixed output voltages are 3V∗, 3.3V, 5V, 6V∗ 7V, 8V, 9V, 10V, 12V, and 15V∗. The maximum current capacity is 1A for
each of the above voltages. (Items marked with an asterisk are under development.)
Applications
Constant voltage power supply
Features
1) Built-in overvoltage protection circuit, overcurrent
protection circuit and thermal shutdown circuit.
2) TO220FP-5 package can be used in wide range of
applications.
3) 0µA (design value) circuit current when switch is off.
4) Richly diverse lineup.
5) Low minimum I / O voltage differential.
Product codes
Absolute maximum ratings (Ta = 25°C)
87
Regulator ICs
Block diagram
88
BAST series
Regulator ICs
BAST series
Pin descriptions
Recommended operating conditions
BA00ST
BA08ST
BA03ST (under development)
BA09ST
BA033ST
BA10ST
BA05ST
BA12ST
BA06ST (under development)
BA15ST (under development)
BA07ST
89
Regulator ICs
Electrical characteristics
BA00ST (unless otherwise noted, Ta = 25°C, VCC = 10V, Io = 500mA)
BA03ST (unless otherwise noted, Ta = 25°C, VCC = 8V, Io = 500mA) (under development)
90
BAST series
Regulator ICs
BAST series
BA033ST (unless otherwise noted, Ta = 25°C, VCC = 8V, Io = 500mA)
BA05ST (unless otherwise noted, Ta = 25°C, VCC = 10V, Io = 500mA)
91
Regulator ICs
BA06ST ( unless otherwise noted, Ta = 25°C, VCC = 11V, Io = 500mA) (under development)
BA07ST (unless otherwise noted, Ta = 25°C, VCC = 12V, Io = 500mA)
92
BAST series
Regulator ICs
BAST series
BA08ST (unless otherwise noted, Ta = 25°C, VCC = 13V, Io = 500mA)
BA09ST (unless otherwise noted, Ta = 25°C, VCC = 14V, Io = 500mA)
93
Regulator ICs
BA10ST (unless otherwise noted, Ta = 25°C, VCC = 15V, Io = 500mA)
BA12ST (unless otherwise noted, Ta = 25°C, VCC = 17V, Io = 500mA)
94
BAST series
Regulator ICs
BAST series
BA15ST (unless otherwise noted, Ta = 25°C, VCC = 20V, Io = 500mA) (under development)
95
Regulator ICs
BAST series
Measurement circuits
(The C pin only exists on the BA00AST, For the BA00AST, place a 6.8 kΩ resistor between the OUT and C pins, and
a 2.2 kΩ resistor between the C and GND pins.)
96
Regulator ICs
Operation notes
(1) Operating power supply voltage
When operating within the normal voltage range and
within the ambient operating temperature range, most
circuit functions are guaranteed. The rated values cannot
be guaranteed for the electrical characteristics, but there
are no sudden changes of the characteristics within
these ranges.
(2) Power dissipation
Heat attenuation characteristics are noted on a separate
page and can be used as a guide in judging power dissipation.
If these ICs are used in such a way that the allowable
power dissipation level is exceeded, an increase in the
chip temperature could cause a reduction in the current
capability or could otherwise adversely affect the performance of the IC. Make sure a sufficient margin is allowed
so that the allowable power dissipation value is not exceeded.
(3) Output oscillation prevention and bypass capacitor
Be sure to connect a capacitor between the output pin
and GND to prevent oscillation. Since fluctuations in the
valve of the capacitor due to temperature changes may
cause oscillations, a tantalum electrolytic capacitor with
a small internal series resistance (ESR) is recommended.
A 22µ F capacitor is recommended; however, be aware
that if an extremely large capacitance is used (1000µ F
or greater), then oscillations may occur at low frequencies. Therefore, be sure to perform the appropriate verifications before selecting the capacitor.
Also, we recommend connecting a 0.33µ F bypass capacitor as close as possible between the input pin and
GND.
(4) Current overload protection circuit
A current overload protection circuit is built into the out-
BAST series
puts, to prevent IC destruction if the load is shorted.
This protection circuit limits the current in the shape of a
’7’. It is designed with a high margin, so that even if a large
current suddenly flows through the large capacitor in the
IC, the current is restricted and latching is prevented.
However, these protection circuits are only good for preventing damage from sudden accidents. The design
should take this into consideration, so that the protection
circuit is not made to operate continuously (for instance,
clamping at an output of 1VF or greater; below 1VF, the
short mode circuit operates). Note that the capacitor has
negative temperature characteristics, and the design
should take this into consideration.
(5) Thermal overload circuit
A built-in thermal overload circuit prevents damage from
overheating. When the thermal circuit is activated, the
various outputs are in the OFF state. When the temperature drops back to a constant level, the circuit is restored.
(6) Internal circuits could be damaged if there are
modes in which the electric potential of the application’s
input (VCC) and GND are the opposite of the electric potential of the various outputs. Use of a diode or other such
bypass path is recommended.
(7) Although the manufacture of this product includes
rigorous quality assurance procedures, the product may
be damaged if absolute maximum ratings for voltage or
operating temperature are exceeded. If damage has occurred, special modes (such as short circuit mode or
open circuit mode) cannot be specified. If it is possible
that such special modes may be needed, please consider using a fuse or some other mechanical safety measure.
(8) When used within a strong magnetic field, be aware
that there is a slight possibility of malfunction.
97
Regulator ICs
Electrical characteristic curves
External dimensions (Units: mm)
98
BAST series