However, to improve system
performance as well as eliminate possible oscillations, the
LM4780 should have its supply leads bypassed with low-inductance
capacitors having short leads that are located close
to the package terminals. Inadequate power supply bypassing
will manifest itself by a low frequency oscillation known as
“motorboating” or by high frequency instabilities. These instabilities
can be eliminated through multiple bypassing utilizing
a large tantalum or electrolytic capacitor (10μF or larger)
which is used to absorb low frequency variations and a small
ceramic capacitor (0.1μF) to prevent any high frequency feedback
through the power supply lines.
If adequate bypassing is not provided, the current in the supply
leads which is a rectified component of the load current
may be fed back into internal circuitry. This signal causes distortion
at high frequencies requiring that the supplies be bypassed
at the package terminals with an electrolytic capacitor
of 470μF or more