米6体育平台手机版

ZHCSQ75C June 2022 – March 2023 UCC28C50-Q1 , UCC28C51-Q1 , UCC28C52-Q1 , UCC28C53-Q1 , UCC28C54-Q1 , UCC28C55-Q1 , UCC28C56H-Q1 , UCC28C56L-Q1 , UCC28C57H-Q1 , UCC28C57L-Q1 , UCC28C58-Q1 , UCC28C59-Q1

PRODUCTION DATA

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机械数据 (封装 | 引脚)

D|8
- MSOI002K

散热焊盘机械数据 (封装 | 引脚)

订购信息

zhcsq75c_oa

9.2.2.2 Primary Magnetizing Inductance of the Flyback Transformer (LM)

Calculate the maximum primary magnetizing inductance (L_{M_CRIT}) to maintain DCM operation at full load and minimum input voltage using the following equation

Equation 8.

L_{M_C R I T} = \frac{V_{I N_M I N} \times D_{V I N_M I N} \times (1 - D_{V I N_M I N}) \times N_{P S}}{2 \times f_{S W} \times I_{O U T}} = \frac{40 V \times 0.80 \times (1 - 0.80) \times 10.3}{2 \times 42.5 k H z \times 1.3 A} = 597 µ H

To account for the inductance variance, a typical L_M of 550 µH is used in the following calculation. P_{O_MAX} occurs when the CS-pin voltage reaches at 1 V. P_{O_MAX} determines the maximum output power of the flyback converter, set 120% larger than the full-load output power of 40 W. Then, the maximum peak magnetizing current (I_{M_MAX}) can be calculated as

Equation 9.

I_{M_M A X} = \sqrt{\frac{2 \times P_{O_M A X}}{L_{M} \times f_{S W} \times η}} = \sqrt{\frac{2 \times (40 W \times 120 %)}{550 µ H \times 42.5 k H z \times 0.85}} = 2.2 A