AN4158 datasheet(30/34 Pages) STMICROELECTRONICS

부품명	AN4158

상세설명	Peak current control with automatic decay adjustment

PDF	34 Pages

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제조업체	STMICROELECTRONICS [STMicroelectronics]

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30 / 34 page

Setup and optimization

AN4158

30/34

DocID023635 Rev 2

Figure 25. TOFF_FAST and TON_MIN parameter relations

5.1.4

FAST_STEP

The FAST_STEP parameter defines the fast decay duration used at current reference

changes; the shorter fast decay value (FAST_STEP/4) is used in the first falling steps, then

the algorithm increases the fast time up to the longer value (FAST_STEP) which is used in

the final part of the sinewave (see Figure 26 and Section 4.1.2 on page 24).

ON_MIN

Reference current

ON_MIN

OFF_FAST /8

OFF_FAST /4

The fast decay time and the following

on-time are almost equal.

if t

OFF_FAST /8 < t ON_MIN than t on< tON_MIN

The minimum fast decay time (t

OFF_FAST /8)

ON_MIN

limit.

A second fast decay is always necessary.

if t

OFF_FAST /8 > tON_MIN than ton > tON_MIN

The minimum fast decay time (t

OFF_FAST /8)

ON_MIN

limit.

never satisfies the t

could satisfy the t

AM15127v1

AN4158 데이터시트(PDF) 30 Page - STMicroelectronics