A7330
DC-DC CONVERTER BUCK (STEP-DOWN)
SENSORLESS CC/CV
AiT Semiconductor Inc.
www.ait-ic.com
capacitors, choose a capacitor with less than 50mΩ ESR.
Rectifier Diode
Use a Schottky diode as the rectifier to conduct current when the High-Side Power Switch is off. The Schottky
diode must have current rating higher than the maximum output current and a reverse voltage rating higher
than the maximum input voltage.
Stability Compensation
The feedback loop of the IC is stabilized by the components at the COMP pin, as shown in figure below.
NOTE ①: CCOMP2 is needed only for high ESR output capacitor
The DC loop gain of the system is determined by the following equation:
0.8V
AVDC
=
x AVEA x GCOMP
I
OUT
The dominant pole P1 is due to CCOMP
:
G
EA
∫
P1
=
2πAVEA
C
COMP
The second pole P2 is the output pole:
I
OUT
∫
=
P2
2πVOUT
C
OUT
The first zero Z1 is due to RCOMP and CCOMP
:
1
∫
Z1
=
2πRCOMP
CCOMP
And finally, the third pole is due to RCOMP and CCOMP2 (if CCOMP2 is used):
1
∫
=
P3
2πRCOMPCCOMP2
The following steps should be used to compensate the IC:
REV1.0
- JAN 2016 RELEASED -
- 10 -
AITSEMI [ AiT Semiconductor ]
