Multilayer ceramic capacitors are an excellent choice for the input decoupling of the step-up converter as they have extremely low ESR and are available in small footprints. Input capacitors should be located as close as possible to the device.

Take care when using only 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 can induce ringing at the V_IN pin. This ringing can couple to the output and be mistaken as loop instability or can even damage the part. Place additional "bulk" capacitance (electrolytic or tantalum) in this circumstance, between C_IN and the power source lead, to reduce ringing that can occur between the inductance of the power source leads and C_IN.