Sample &
Buy Product
Folder Support &
Community Tools &
Software Technical
Documents TPS53315
SLUSAE6A – DECEMBER 2010 – REVISED DECEMBER 2015 TPS53315 12-A Step-Down Regulator with Integrated Switcher
1 Features 2 Applications 1 Conversion Input Voltage Range: 3 V to 15 V
VDD Input Voltage Range: 4.5 V to 25 V
Output Voltage Range: 0.6 V to 5.5 V
5-V LDO Output
Integrated Power MOSFETs with 12-A Continuous
Output Current N Вґ ON
R7 Вґ C1
2
where N is the coefficient to account for L and COUT variation. (14) Submit Documentation Feedback Copyright © 2010–2015, Texas Instruments Incorporated Product Folder Links: TPS53315 21 TPS53315
SLUSAE6A – DECEMBER 2010 – REVISED DECEMBER 2015 www.ti.com N is also used to provide enough margin for stability. It is recommended N = 2 for VOUT ≤ 1.8 V and N = 4 for
VOUT ≥ 3.3 V or when L ≤ 250 nH. The higher VOUT needs a higher N value because the effective output
capacitance is reduced significantly with higher DC bias. For example, a 6.3-V, 22-ВµF ceramic capacitor may
have only 8 ВµF of effective capacitance when biased at 5 V.
Because the VFB pin voltage is regulated at the valley, the increased ripple on the VFB pin causes the increase
of the VFB DC value. The AC ripple coupled to the VFB pin has two components, one coupled from SW node
and the other coupled from the VOUT pin and they can be calculated using Equation 15 and Equation 16 when …
