Although an input capacitor is not required for stability if input impedance is very low, good analog design practice is to connect a 0.1-μF to 1-μF low equivalent series resistance (ESR) capacitor across the input supply near the regulator. This capacitor counteracts reactive input sources and improves transient response, noise rejection, and ripple rejection. A higher-value capacitor can be necessary if large, fast rise-time load transients are anticipated or the device is located several inches from the power source.

The TPS737 requires a 1-μF output capacitor for stability. The device is designed to be stable for all available types and values of capacitors. In applications where multiple low-ESR capacitors are in parallel, ringing can occur when the product of C_OUT and total ESR drops below 50 nF·Ω. Total ESR includes all parasitic resistances, including capacitor ESR and board, socket, and solder joint resistance. In most applications, the sum of capacitor ESR and trace resistance meets this requirement.