SBVS336A September 2021 – May 2022 TPS7A94
For best transient response, use the nominal value or larger capacitor from OUT to ground as listed in the Section 6.3 table. Place the output capacitor as close to the OUT and GND pins of the device as possible.
For best transient response and to minimize input impedance, use the nominal value or larger capacitor from IN to ground as listed in the Section 6.3 table. Place the input capacitor as close to the IN and GND pins of the device as possible.
The load-step transient response is the LDO output voltage response to load current changes. There are two key transitions during a load transient response: the transition from a light to a heavy load, and the transition from a heavy to a light load. The regions shown in Figure 8-17 are broken down in this section. Regions A, E, and H are where the output voltage is in steady-state regulation.
During transitions from a light load to a heavy load:
During transitions from a heavy load to a light load:
Transitions between current levels changes the internal power dissipation because the device is a high-current device (region D). The change in power dissipation changes the die temperature during these transitions, and leads to a slightly different voltage level. This temperature-dependent output voltage level shows up in the various load transient responses.
A larger output capacitance reduces the peaks during a load transient but slows down the response time of the device. A larger dc load also reduces the peaks because the amplitude of the transition is lowered and a higher current discharge path is provided for the output capacitor.