VOLTAGE REGULATION STEP-UP CHARGE PUMP DC-DC CONVERTER

S-8821 Series

Seiko Instruments Inc.

11

External Capacitor Selection

capacitor with a small equivalent series resistance (ESR). Although this figure varies according to the

impedance of the power supply that is used as well as the load current value, it is generally in the range

of 4.7

μF to 10 μF.

voltage. A value of 10

μF is recommended for the capacitance value. Use of a capacitor with a

capacitance lower than 10

μF results in a larger ripple voltage. Conversely, use of a capacitor with a

capacitance greater than 10

μF results in the output voltage not being able to rise up to setting value

and the impossibility to obtain the desired output current.

small ESR. A capacitance value of 0.10

μF is recommended. Use of a capacitor with a capacitance

greater than 0.10

μF results in a larger ripple voltage. Conversely, use of a capacitor with a capacitance

lower than 0.10

μF results in the output voltage not being able to raise up to setting value and the

impossibility to obtain the desired output current.