TLE8386-2EL Datasheet, PDF (24/32 Pages) Infineon Technologies AG – Basic Smart Boost Controller

TLE8386-2EL
Application Information
The value of the sense resistor R_CS can be calculated as follows:
R_CS
=
0----,_-8---0-----×_{-----V----S---W-----C---S-}
I_BOOSTPEAK
• I_BOOSTPEAK = peak current through the boost inductor L_BOOST (will be calculated at boost inductor selection)
Boost inductor L_BOOST selection:
The important parameters for selecting the boost inductor are:
• Inductor L_BOOST
• Maximum RMS current rating I_BOOSTRMS for thermal design
• Saturation current threshold I_BOOSTSAT
The maximum average inductor current is:
I_BOOSTMAX
=
I_BOMAX
×
-----------1-------------
1 – D_MAX
The ripple current through the boost inductor is:
∆I_BOOST
=
χ × I_BOOSTMAX
=
χ
×
I_BOMAX
×
-----------1------------
1 – D_MAX
The peak current through the boost inductor is:
I_BOOSTPEAK = I_BOOSTMAX × _1 + ^χ-2-_ < I_BOOSTSAT
(The peak current trough the boost inductor must be smaller than the saturation current threshold!)
The RMS current through the boost inductor is:
I_BOOSTRMS = I_BOOSTMAX ×
1 + -^χ---²-
12
The boost inductor value L_BOOST can be calculated by the following equation:
L_BOOST = -_∆----I--_B---_O--V--_O---^IS--^N-_T--^M--_×---^I-^N-f--_F---_R---_E---_Q-- × D_MAX
Data Sheet
22
Rev. 1.0, 2010-10-25