An input capacitor, CI, is recommended to buffer line influences. Connect the capacitors close to the IC pins.
The output capacitor for the TPS7B4250-Q1 device is required for stability. Without the output capacitor, the regulator oscillates. The actual size and type of the output capacitor can vary based on the application load and temperature range. The effective series resistance (ESR) of the capacitor is also a factor in the IC stability. The worst case is determined at the minimum ambient temperature and maximum load expected. To ensure stability of TPS7B4250-Q1 device, the device requires an output capacitor between 1 µF and 50 µF with an ESR range between 0.001 Ω and 20 Ω that can cover most types of capacitor ESR variation under the recommend operating conditions. As a result, the output capacitor selection is flexible.
The capacitor must also be rated at all ambient temperature expected in the system. To maintain regulator stability down to –40°C, use a capacitor rated at that temperature.