Technical Note

8/11

www.rohm.com

2011.03 - Rev.C

© 2011 ROHM Co., Ltd. All rights reserved.

●

Peripheral Circuit Considerations

・

Vcc Terminal

Please attach a capacitor (greater than 0.33µF) between the Vcc and GND.

The capacitance values will differ depending on the application, so please take this into account when configuring the terminal.

・

GND Terminal

Please be sure to keep the set ground and IC ground at the same potential level so that a potential difference does not

arise between them.

If a potential difference arises between the set ground and the IC ground, the preset voltage will not be outputted, causing

the system to become unstable. Therefore, please reduce the impedance by making the ground patterns as wide as

possible and by reducing the distance between the set ground and the IC ground as much as possible.

・

CTL Terminal

The CTL terminal is turned ON at 2.0V and higher and OFF at 0.8V and lower within the operating power supply voltage range.

The power supply and the CTL terminal may be started up and shut down in any order without problems.

●

Vo Terminal

Fig.32 Output Equivalent Circuit

Fig.33 ESR-Io Characteristics

Fig.34 ESR vs Io Characteristics

(BA□□CC0)

(B A□□DD0)

due to factors such as temperature changes, making it impossible to completely stop oscillations. Please use a tantalum

capacitor or aluminum electrolysis capacitor with favorable characteristics and small internal series resistance (ESR) even at

low temperatures. The output fluctuates regardless of whether the ESR is large or small. Please use the IC within the stable

operating region while referring to the ESR characteristics reference data shown in Figs.32 through 34. In applications where

there are sudden load fluctuations, the use of a capacitor with large capacitance is recommended.

OUT

22μF

IC

OUTPUT CURRENT：lo(mA)

200

400

800

1000

0.1

1

10

Stable operating region

100

0

600

Unstable operating region

Unstable operating region

10000

1

0.1

1

10

100

1

OUTPUT CURRENT：lo(mA)

Unstable operating region

Unstable operating region

Stable operating region

10

100

1000