11/22
XC9220/XC9221
Series
■NOTES ON USE
1. The XC9220/XC9221 series are designed for use with an output ceramic capacitor. If, however, the potential
difference between input and output is too large, a ceramic capacitor may fail to absorb the resulting high switching
energy and oscillation could occur on the output. If the input-output potential difference is large, connect the output
capacitor with large performance to compensate for insufficient capacitance.
2. Spike noise and ripple voltage arise in a switching regulator as with a DC/DC converter. These are greatly influenced
by external component selection, such as the coil inductance, capacitance values, and board layout of the external
components. Once the design has been completed, verification with actual components should be done.
3. When the difference between input voltage and output voltage is large in PWM control, and the load current is light,
very narrow pulses will be outputted, and there is the possibility that some cycles my be skipped completely.
4. When the difference between input voltage and output voltage is small in PWM control, and the load current is heavy,
very wide pulses will be outputted and there is the possibility that some cycles my be skipped completely.
5. When using the CE pin by pulling up to the V
IN
pin, please be noted to the rising time of the V
IN
pin voltage. If the
rising time of the V
IN
pin voltage is much slower than the soft-start time of the XC9220/XC9221 series, the
short-protection circuit starts to operate so that the output may not rise. If you are using the A or the C series, please
use a voltage detector or something similar in order to check that the input voltage rises fully. Then, start the series via
the CE pin. If you don’t want to use an additional detector in this way, we recommend that you use the B or D series,
adjusting the soft-start period externally so that the voltage at the V
IN
pin rises fully before the soft-start period is
completed.
6. Use of the IC at voltages below the recommended minimum operating voltage may lead to instability.
7. This IC and external components should be used within the stated absolute maximum ratings in order to prevent
damage to the device.
