RP100x

NO.EA-140-160425

6

TYPICAL APPLICATION

C1

RP100x

Series

CE

GND

C2

(External Components)

C2

1.0

μF

MURATA: GRM155B31A105KE15

TECHNICAL NOTES

When using these ICs, consider the following points:

Phase Compensation

In these ICs, phase compensation is made for securing stable operation even if the load current is varied. For

this purpose, use a capacitor C2 with good frequency characteristics and ESR (Equivalent Series Resistance).

Ceramic capacitors have different temperature characteristics and bias characteristics depending on their

dimensions and manufacturers. If the setting voltage is 2.5V or more and the capacitor’s dimensions for V

OUT

equal to 1.0mm by 0.5mm or smaller than that, the capacitance value might be extremely low. As a result, the

capacitance might be much less than expected value. In such cases, the operation might be unstable at low

temperature. (

−20°C or less) In that case, use a larger capacity, or a large dimensions’ capacitor. (For

example 1.6mm by 0.8mm)

If a tantalum capacitor is selected as an output capacitor, large ESR may be a cause of unstable operation.

Evaluate the operation of PCB with considerable frequency characteristics.

PCB Layout

Connect a capacitor C1 with a capacitance value as much as 1.0

close as possible to the pins.

Set external components, especially the output capacitor C2, as close as possible to the ICs, and make wiring

as short as possible.