Ballast design

AN3040

14/27

Doc ID 16181 Rev 2

3.2.4

Power MOSFET

The MOSFET's power dissipation depends on the conduction and switching losses.

this was the correct choice.

3.2.5

Boost diode

The boost freewheeling diode is a fast recovery one. The breakdown voltage is fixed with the

same criterion as the MOSFET. The value of its DC and RMS current, needed to choose the

current rating of the diode, are reported.

Equation 17

Since the PFC works in transition mode, we have used the Turbo 2 ultrafast high-voltage

rectifier STTH1L06.

3.3

Design of the half-bridge inverter and choice of preheating

inductor

According to the criteria described in AN993 chapter 5 (design tips) with regard to the

design of the resonant circuit, the following values have been selected.

●

●

●

We have used the inductor 1646-0005 manufactured by MAGNETICA.

A SuperMESH3 power MOSFET STD7N52K3 has been inserted in the half-bridge section

to reduce the power losses.

For the preheating inductor, we have selected a common mode choke-type inductor with the

A

171

.

0

V

P

I

BUSpfc

outTOT

dc

2

D

=

=

A

53

.

0

V

V

9

2

4

I

2

2

I

BUSpfc

inrmsMin

inrmsMax

rms

2

D

=

⋅

π

⋅

⋅

=

L

res

L

1

L

2

2.2 mH

=

=

=

C

res

C

9

C

14

4.7nF 1600 V

,

=

=

=

C

block

C

12

C

15

100 nF 400 V

,

=

=

=