lm2735xsdx National Semiconductor Corporation, lm2735xsdx Datasheet - Page 18

• Manufacturer Part Number: lm2735xsdx
• Description: 520khz/1.6mhz - Space-efficient Boost And Sepic Dc-dc Regulator
• Manufacturer: National Semiconductor Corporation

www.national.com
Substituting I
The average inductor current of L2 is the average output load.
FIGURE 15. Inductor Volt-Sec Balance Waveform
L1
into I
L2
FIGURE 16. SEPIC CONVERTER Schematic
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Applying Charge balance on C1:
Since there are no DC voltages across either inductor, and
capacitor C6 is connected to Vin through L1 at one end, or to
ground through L2 on the other end, we can say that
Therefore:
This verifies the original conversion ratio equation.
It is important to remember that the internal switch current is
equal to I
so that the minimum guaranteed peak switch current limit
(2.1A) is not exceeded.
L1
and I
L2
. During the D interval. Design the converter
V
C1
= V
IN
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