A load transient is a sudden change in the load current, and an LDO response to a load transient is an important characteristic of the LDO. Load transient response is influenced by the LDO internal compensation, the dynamic bandwidth of the internal error amplifier, and by both output capacitance and parasitics. A poor load transient response (excessive undershoot, overshoot, or ringing) can impact the operation of components to which the LDO provides power. For additional information on load transients, refer to Understanding the Load-Transient Response of LDOs analog design journal.

In the following section, two load transient setup conditions are described. Conditions were tested using the device TPS7A57, which is a high speed LDO. With a high speed LDO, additional circuit inductance becomes apparent in a transient measurement. One condition has significant trace parasitics due to long cabling, while the other condition has limited trace parasitics and a closer connection to the DUT.