JAJSMG2 データシート

JAJSMG2 November 2023 TPS6287B10 , TPS6287B25

PRODMIX

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）

RZV|24
- MPQF690A

サーマルパッド・メカニカル・データ

発注情報

jajsmg2_oa

9.4.2.2 Selecting the Output Capacitors

If the converter remains in regulation, the minimum output capacitance required is given by:

Equation 26.

C_{O U T (m i n) (r e g)} = (\frac{τ \times g_{m} \times R_{Z}}{2 \times π \times \frac{L}{N_{ϕ}} \times \frac{f_{S W}}{4}}) (1 + \sqrt{{T O L}_{I N D}^{2} + {T O L}_{f S W}^{2}})

Equation 31.

C_{O U T (m i n) (r e g)} = (\frac{12.5 \times 10^{- 6} \times 1.5 \times 10^{- 3} \times 3.3 \times 10^{3}}{2 \times π \times \frac{105 \times 10^{-9}}{2} \times \frac{1.5 \times 10^{6}}{4}}) (1 + \sqrt{20 %^{2} + 10 %^{2}}) F = 612.7 μ F

If the converter loop saturates, the minimum output capacitance is given by:

Equation 28.

C_{O U T (m i n) (s a t)} = \frac{1}{∆ V_{O U T}} (\frac{\frac{L}{N_{ϕ}} \times {(∆ I_{O U T} + \frac{I_{L (P P)}}{2})}^{2}}{2 \times V_{O U T}} - \frac{∆ I_{O U T} \times t_{t}}{2}) (1 + {T O L}_{I N D})

Equation 29.

C_{O U T (m i n) (s a t)} = \frac{1}{24 \times 10^{- 3}} (\frac{105 \times 10^{- 9} \times {(24 + \frac{1. 84}{2})}^{2}}{2 \times 0.75} - \frac{24 \times 1 \times 10^{- 6}}{2}) (1 + 20 %) F = 623 μ F

In this case, choose C_OUT(min) = 623 µF, as the larger of the two values, for the output capacitance.

When calculating worst-case component values, use the value calculated above as the minimum output capacitance required. For ceramic capacitors, the nominal capacitance when considering tolerance, DC bias, temperature, and aging effects is typically two times the minimum capacitance. In this case the nominal capacitance is thus 1246 µF.