Datasheet

Input Capacitor Selection
LAYOUT CONSIDERATIONS
TPS62250
www.ti.com .......................................................................................................................................................................................... SLVS842 – SEPTEMBER 2008
An input capacitor is required for best input voltage filtering, and minimizing the interference with other circuits
caused by high input voltage spikes. For most applications, a 4.7 µ F to 10 µ F ceramic capacitor is recommended.
Because ceramic capacitor loses up to 80% of its initial capacitance at 5 V, it is recommended that 10 µ F input
capacitors be used for input voltages > 4.5V. The input capacitor can be increased without any limit for better
input voltage filtering. Take care when using only small ceramic input capacitors. When a ceramic capacitor is
used at the input and the power is being supplied through long wires, such as from a wall adapter, a load step at
the output or VIN step on the input can induce ringing at the VIN pin. This ringing can couple to the output and
be mistaken as loop instability or could even damage the part by exceeding the maximum ratings.
Table 2. List of Capacitors
CAPACITANCE TYPE SIZE SUPPLIER
4.7 µ F GRM188R60J475K 0603 1.6x0.8x0.8mm
3
Murata
10 µ F GRM188R60J106M69D 0603 1.6x0.8x0.8mm
3
Murata
Figure 37. Suggested Layout for Fixed Output Voltage Options
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