BA□□BC0 Series,BA□□BC0W Series,BA00BC0W Series
Technical Note
6/8
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2009.04 - Rev.A
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31kΩ
2kΩ
27kΩ
CTL
Notes for use
Vcc pin
Insert a capacitor (0.33
F approx.) between VCC and GND.
The capacitance will vary depending on the application. Use a suitable capacitance and implement designs with
sufficient margins.
GND pin
Verify that there is no potential difference between the ground of the application board and the IC.
If there is a potential difference, the set voltage will not be output accurately, resulting in unstable IC operation.
Therefore, lower the impedance by designing the ground pattern as wide and as short as possible.
CTL pin
The CTL pin turns on at an operating power supply
voltage of 2.0 V or higher and turns off at 0.8 V or lower.
There is no particular order when turning the power
supply and CTL pins on or off.
Fig.20 Input Equivalent Circuit
Vo pin
Iinsert a capacitor between the Vo and GND pins in order to prevent output oscillation.
Fig.21 Output Equivalent Circuit
Fig.22 ESR vs IO(22μF)
The capacitance may vary greatly with temperature changes, thus making it impossible to completely prevent oscillation.
Therefore, use a tantalum aluminum electrolytic capacitor with a low ESR (Equivalent Serial Resistance). The output will
oscillate if the ESR is too high or too low, so refer to the ESR characteristics in Fig. 20 and operate the IC within the stable
region. Use a capacitor within a capacitance between 22
F and 1,000F.
Below figure,it is ESR-to-Io stability Area characteristics,measured by 22μF-ceramic-capacitor and resistor connected in series.
This characteristics is not equal value perfectly to 22F-aluminum electrolytic capacitor in order to measurement method.
Note, however, that the stable range suggested in the figure depends on the IC and the resistance load involved, and can
vary with the board’s wiring impedance, input impedance, and/or load impedance. Therefore, be certain to ascertain the final
status of these items for actual use.
Keep capacitor capacitance within a range of 22F~1000μF. It is also recommended that a 0.33μF bypass capacitor be
connected as close to the input pin-GND as location possible. However, in situations such as rapid fluctuation of the input
voltage or the load, please check the operation in real application to determine proper capacitance.
OUT
22 F
IC
200
400
600
800
1000
0
0.05
0.075
0.1
0.2
0.5
1.0
2.0
Io [mA]
ESR
[
]
Oscillation region
Stable region
10.0