AN3392 datasheet(14/57 Pages) STMICROELECTRONICS

Part #	AN3392

Description	The SPV1020 is a monolithic DC-DC boost converter designed

PDF	57 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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14 / 57 page

Application efficiency

AN3392

14/57

Doc ID 018749 Rev 1

Application efficiency

In designing a boost application, a typical constraint is the maximum output current ripple.

Once frequency, input, and output voltage are defined, this ripple is directly related to the

inductance value in the application:

Equation 3

The inductance value can be designed for a single-ended architecture and then divided by 4

in the case of IL-4 architecture.

Each inductor, due to its internal resistance (RL), can affect system efficiency. For high

current applications, an inductor with a compact geometry may compromise the efficiency

requirements.

Using the same ferromagnetic material, higher inductance can be achieved by increasing

the inductor geometry, or by increasing the number of turns but using a thinner wire.

In order to save space and cost, the latter solution is preferred but this increases the internal

resistance and the saturation current of the inductor.

ripple

Lmax

Lmin

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⋅

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AN3392 Datasheet(PDF) 14 Page - STMicroelectronics