Dimensioning The Power Components; Preliminary Definition; Rectifier; Input Capacitor - ST STM32F103ZE User Manual

STEVAL-ISF002V1 hardware description
3.3

Dimensioning the power components

This section describes how to dimension the power components relating to the power
section shown in
3.3.1

Preliminary definition

Based on the electrical characteristics listed in
are calculated.
Equation 1
Equation 2
Equation 3
3.3.2

Rectifier

The following equation is a calculation of the power rate for the bridge rectifier.
Equation 4
3.3.3

Input capacitor

A ripple of 20% has been chosen for the inductor current I
ripple is 6%.
Therefore:
Equation 5
Equation 6
Equation 7
This capacitor has to be in class X2 so its value must be 0.22 µF.
12/62
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Figure 5 and the electrical characteristics shown in
P
=
out
I
in(rms) ⋅ η ⋅
V PF
in(min)
=
I I
in(pk) in(rms)
2
=
I
in(avg)
= ⋅ ⋅
P 2 V I
Bridge F in(avg)
=
I 0
ripple
= ⋅
V . 0 06 V
in(ripple) in(pk)
max
I
ripple
= =
C
in
⋅ ⋅
8 f V
sw in(ripple)
Doc ID 16854 Rev 1
Section 3.1, the following maximum values
1400
= =
A . 8
⋅ ⋅
. 0 95 185 . 0 99
⋅ =
2 11 . 38 A
⋅ ⋅
I 2
in(pk)
=
. 7 24 A
π
( )
= ⋅ ⋅ =
2 0 8 . . 7 24 W 11
and it is assumed that the Vin
L
⋅ =
2 . I . 2 28 A
in(pk)
( )
= ⋅ ⋅ =
. 0 06 265 2 V
. 2 28
=
μF
. 0
⋅ ⋅ 3 ⋅
8 80 10 22 . 49
UM0877
Section 3.1.
05 A
6 . W
22 . 49 V
μF
158