A7406A
AiT Semiconductor Inc.
DC-DC CONVERTER BUCK (STEP-DOWN)
40V, 600mA ASYNCHRONOUS
www.ait-ic.com
APPLICATION INFORMATION
Setting the Output Voltage
The output voltage is set using a resistive voltage divider from the output voltage to FB pin.
VFB=VOUT*R2/(R1+R2)
The feedback resistor R1 also sets the feedback loop bandwidth with the internal compensation capacitor.
Choose R1 around 124kΩ for optimal transient response.
Inductor
The inductor is required to supply constant current to the output load. A larger value inductor will result in
lower output ripple voltage. Generally, a good rule for determining the inductance to use is to allow the
peak-to-peak ripple current in the inductor to be approximately 30% of the maximum load current.
Also, make sure that the peak inductor current is below the maximum switch current limit.
Input Capacitor
The input capacitor (C1) can be electrolytic, tantalum or ceramic. When using electrolytic or tantalum
capacitors, a small, high quality ceramic capacitor, i.e.
0.1μF, should be placed as close to the IC as possible.
Output Capacitor
The output capacitor (C2) is used to maintain the DC output voltage. Ceramic, tantalum, or low ESR
electrolytic capacitors are recommended. Low ESR capacitors are preferred to keep the output voltage ripple
low.
REV1.0
- MAR 2018 RELEASED -
- 8 -
AITSEMI [ AiT Semiconductor ]
