MB39A112EVB-01
Ripple current : Peak value
The peak ripple current must be within the rated current of the inductor.
If the peak ripple current is IL, it is obtained by the following formula.
VIN Vo2
IL IO
tON
2L
12 3.3
2 3.3 10
1
1.0
6
2300 103 0.275
1.16 A
Ripple current : peak-to-peak value
If the peak-to-peak ripple current is IL, it is obtained by the following formula.
VIN Vo2
IL
tON
L
12 3.3
1
3.3 10
2300 103 0.275
6
0.315 A
9.2.3 Flyback diode (SBE001 : SANYO product)
VR (DC reverse voltage) 30 V, average output current 2.0 A, peak surge current 20 A
VF (forward voltage) 0.55 V, at IF 2.0 A
VR : The value enough to satisfy the input voltage 30 V
On time of the diode is assumed to be tD (Max) , the diode mean current IDi is obtained by the following formula.
Vo2
VIN
IDi Io (1
) 1.0 (1 0.275) 0.725 A
On time of the diode is assumed to be tD (Max) , the diode peak current IDip is obtained by the following formula.
Vo2
IDip
(Io
tOFF) 1.16 A
2L
Document Number: 002-08322 Rev. *A
Page 19 of 23
CYPRESS [ CYPRESS ]
