JAJSU64A April 2024 – August 2024 TPS7H4011-SP
PRODMIX
デバイスごとのパッケージ図は、PDF版データシートをご参照ください。
The soft-start capacitor CSS, determines the amount of time it takes for the output voltage to reach its nominal programmed value during power up. This is useful if a load requires a controlled voltage slew rate. This is also used if the output capacitance is large (as is typical with space grade buck converters), which would require a large amount of current to quickly charge the capacitor to the output voltage level. The large currents necessary to charge the capacitor may make the TPS7H4011 reach the current limit, draw excessive current from the input power supply, or cause the input voltage rail to sag. Limiting the output voltage slew rate solves these problems. The soft-start capacitor value can be calculated using Equation 7.
A reasonable soft start time for many space grade buck regulators is 5.8ms, which results in a CSS capacitor of 22nF.