A7115
AiT Semiconductor Inc.
DC-DC CONVERTER
www.ait-ic.com
1.5MHZ, 1.5A SYNCHRONOUS STEP-DOWN CONVERTER
Input Capacitor Selection
The input capacitor reduces the surge current drawn from the input and switching noise from the device. The
input capacitor impedance at the switching frequency shall be less than input source impedance to prevent
high frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS
current must be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of
their low ESR and small temperature coefficients. A 22μF ceramic capacitor for most applications is sufficient.
Output Capacitor Selection
The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability.
The output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or
X7R dielectrics are recommended due to their low ESR and high ripple current. The output ripple VOUT is
determined by:
REV1.0
- APR 2013 RELEASED, NOV 2014 UPDATED -
- 10 -
AITSEMI [ AiT Semiconductor ]
