The devices of the TPS6213x family are internally compensated to be stable with L-C filter combinations corresponding to a corner frequency to be calculated with Equation 12:

Equation 12.

Proven nominal values for inductance and ceramic capacitance are given in Table 9-2 and are recommended for use. Different values can work, but care has to be taken on the loop stability which will be affected. More information including a detailed LC stability matrix can be found in Optimizing the TPS62130/40/50/60 Output Filter Application Report.

The TPS6213x devices, both fixed and adjustable output voltage versions, include an internal 25-pF feedforward capacitor, connected between the VOS and FB pins. This capacitor impacts the frequency behavior and sets a pole and zero in the control loop with the resistors of the feedback divider, per Equation 13 and Equation 14:

Equation 13.

Equation 14.

Though the TPS6213x devices are stable without the pole and zero being in a particular location, adjusting their location to the specific needs of the application can provide better performance in power save mode, improved transient response, or both. An external feedforward capacitor can also be added. A more detailed discussion on the optimization for stability versus transient response can be found in Optimizing Transient Response of Internally Compensated DC-DC Converters Application Report and Feedforward Capacitor to Improve Stability and Bandwidth of TPS621/821-Family Application Report.